Nema 250 PDF
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NEM
250
COPYRIGHT National COPYRIGHT National Electrical Electrical Manufacturers Manufacturers Association ssociation
Licensed by Licensed by Information Information Handling Handling Services Services
ANSI Approval Date August 3 0 ,2 0 0 1
NEMA Standards Publication No. ANSIINEMA 250-1997 Enclosures for Electrical Equipment I O
Volts Maximum)
Published by: National Electric al Manufacturers Asso ciation 1300 North 17th Street, Suite 1847 Rosslyn, VA 22209
O Copyright Copyright 2001 by the National Nation al Electrical Manufacturers Association. All rights including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the th e Protection P rotection of Literary and Artistic Works, and the International and Pan American Copyright Conventions.
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NOTICE AND DISCLAIMER The information in this publication was considered considered technically sound by the consensus of persons engaged in the development and approval of the document at the time it was developed. Consensus does not necessarily mean that there is unanimous un animous agreement among every person participating in the development develo pment of this document. The National Electrical Electri cal Manufacturers Association Association (NEMA) (NEMA) standards and guideline publications, of which the document contained herein is one, are developed through a voluntary consensus standards development process. This process brings together volunteers volun teers and/or seeks out the views of persons who have an interest in the topic covered by this publication. While NEMA administers the process and establishes rules to promote fairness in i n the development de velopment of consensus, it does not write the document and it does not independently test, evaluate, or verify the accuracy or completenes completeness s of any information or the soundness of any judgments contained in its standards and guideline publications. publications. NEMA disclaims liability for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, application, or reliance on this document. NEMA NEMA disclaims and makes mak es no guaranty or warranty, expressed or implied, as to the accuracy or completeness of any information published herein, and disclaims and makes no warranty that the information in this document will fulfill any of your particular purposes or needs. NEMA NEMA does does not undertake undertake to guarantee the performance pe rformance of any individual individu al manufacturer or seller’s products o r services by virtue of this standard or guide. In publishing pub lishing and making this document available, available, NEMA NEMA is not undertaking to render professional or other services for o r on behalf of any person or entity, nor is NEMA NEMA undertakingto perform any duty owed by any person o r entity to someone someone else. else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable reasona ble care in any given circumstances. circums tances. Information and other standards standards on the topic top ic covered by this publication may be available from other sources, which the user may wish to consult for additional views or information not covered by this publication. NEMA has no power, nor does it undertake to police or enforce compliance with the contents of this document. NEMA NEMA does not certify, certify, test, or inspect products, designs, or installations for safety or health purposes. Any certification certific ation or other statement of compliance with any health or safety-related safety-r elated information in this document document shall not be attributable attributable to NEMA NEMA and is solely the responsibility of the certifier or maker of of the statement. sta tement.
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STDaNEMA NEMA NEM A 250-1997 250-1997
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........................................................... ........................................................... ................................... ......19 5. 5.2. 2.2 Ventilated Enclosures E nclosures Test Method............................. .......................................................... .......................................................... ........................................................... .............................................. ................19 5.2.3 Evaluation............................. 5.3 DRIP TEST ........................................................................................................................................... 19 5.3.1 Method A ....................................................................................................................................... 19 5.3.2 Method B ...................................................................................................................................... 19 5.3.3 Evaluation..................................................................................................................................... 19 5.4 RAIN TEST ........................................................................................................................................... 19 5.4.1 Method.......................................................................................................................................... 19 5.4.2 Evaluation 20 5.5 DUST TEST .......................................................................................................................................... ..................................................................................................................................... 23 5. 5.5. 5.1 1 Outdoor Outd oor Dust Test Tes t ........................................................................................................................ 23 5. 5.5. 5.2 Indoor Indo or Dust Tests ......................................................................................................................... 24 5. 5.6 6 EXTERNAL ICING TEST ...................................................................................................................... 25 5. 5.6.1 6.1 Test Method Metho d.................................................................................................................................. 25 5.6.2 Evaluation..................................................................................................................................... 26 5.7 HOSEDOWN TEST .............................................................................................................................. 26 5. 5.7. 7.1 1 Test Method.................................................................................................................................. 26 5.7.2 Evaluation..................................................................................................................................... 26 5.8 Indoor Corrosion Corro sion Protection Protect ion (Rust-ResistanceTest (24-Hour (24-Hour Salt Sa lt Spray Test)) .................................. 26 .......................................................... ........................................................... ........................................................... ..................................... ........26 5. 5.8. 8.1 1 Test Equipment Equipm ent............................. 5. 5.8. 8.2 2 Salt Soluti Sol ution on ................................................................................................................................. 27 5.8.3 Air Supply............. .......................... .......................... ........................... ........................... .......................... .......................... .......................... ........................... ........................... ............... .. 27 .......................... ............. .......................... .......................... .......................... ........................... ........................... .......................... .......................... ........................ ........... 5.8.4 Temperature 27 5.8.5 5.8 .5 Test Procedure Proce dure ............................................................................................................................. 27 5.8.6 Evaluation..................................................................................................................................... 27 5.9 OUTDOOR CORROSION PROTECTION PROTECTION ........................................................................................... 27 5. 5.9. 9.1 1 600 Hour Salt Spray Spra y Test.............................................................................................................. 27 5.9.2 Evaluation..................................................................................................................................... 27 5. 5.9. 9.3 1200 Hour Moist Carbon Dioxide . ulfur Dioxide . ir Test ........................................................27 5.1 O TYPE 4X CORROSION PROTECTION PROTECTION ............................................................................................. 28 ................................... .................................... .................................... .................................... ..................................... ..................................... ....................... ..... 28 5. 5.1 1 0. 0.1 1 Evaluatio Evalu ation n................. 5.1 1 SUBMERSION TEST.......................................................................................................................... 28 5.1 i1 Test Method................................................................................................................................ 28 .......................... ........................... ........................... .......................... .......................... .......................... ........................... ........................... ......................... ............ 28 5. 5.1 1 1. 1.2 2 Evalu Ev aluati ation on............. 5.12 PRESSURE TEST .............................................................................................................................. 28 5. 5.1 1 2.1 Altern A lternate ate Tests............................................................................................................................ 28 5.13 OIL EXCLUSION TEST ...................................................................................................................... 29 ................................................................................................................................ 5.13. 5.1 3.1 1 Test Method 29 5.13. 3.2 2 Evalua Eva luatio tion n................................................................................................................................... 29 5.14 GASKET TESTS TEST S................................................................................................................................. 29 5.1 4. 4.1 1 Aging Test................................................................................................................................... 29 ....................................................... .......................................................... .......................................................... ............................................... .................. 30 5.14.2 Evaluation.......................... .......................................................... .......................................................... ......................................................... ................................ .... 30 5.1 4.3 Oil immersion est .............................
APPENDIX A
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NEMA NEM A 250-1997 250-1997
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FOREWORD This Standards Sta ndards Publication Publ ication covers covers the classification classification and description of enclosures for electrical equipment. equipme nt. Enclosur Encl osures es or o r rotating rotatin g apparatus apparatu s have not been included. The T he primary purpose of this publication s to permit a potential user to determi determine: ne:
1. The type of enclosure appropriate for the application application.. 2. The features the enclosure s expected to have. 3. The tests applied app lied to the enclosure to demonstrate ts conformance o the description. These standards standard s are used by the electrical industry o provide guidelines for the manufactureand proper application of enclosures and to promote the benefits o off repetitive manufacturing manufacturingand widespread enclosure availability.
Each type of enclosure s described in general and functional terms where where practicable, and omits reference o structural struct ural details and specific applications except where they are essential to the identification of the enclosure type. For such structural details and specific specific applications, see the appropriate NEM NEMA A product standards standards publication. publicatio n. Individual product standards publications incorporating enclos enclosure ure construction unique to the th e product design may reflect the type of designations contained herein provided the design desig n tests for such construction equal or exceed the requirements of these Standards Publication. Publication. User needs have been considered consi dered throughout throughout the developmentof this publication. Proposedor recommended recomm ended revisions revi sions should shou ld be submitted submit ted to: to: Vice President EngineeringDepartment National Electri El ectrical cal Manufacturers Association 1300 N. N. 17th Street Suite 1847 Rosslyn, VA 22209 Publication250-1 Publication 250-1997 997 revises and supersedes Publication250-1991. 250-1991.
This Standar Standards ds Publication Publ ication was developed by the NEMA Section Sections s lilisted sted below. Section Section approval appr oval of the standard standa rd does not necessarily necessari ly imply that all al l section members members voted for its approva approvall or participated n its development. At the time it was approved, the the Sections were composed of the following following members: INDUSTRIAL CONTROL & SYSTEM SYSTEMS S SECTIO SECTION N
AB6 Control, Inc.-Wichita Falls, TX Automatic Switch Switch Company-Florham Park, N J Baldor Electr Electric ic Company-Woodinville Company-Woodinville,, WA Balluff, Inc.-Florence, KY Bussmann Bussm ann Div/Cooper Indust.-Ellisville, Indust.-Ellisville, M O CEGELEC Au Autom tomati ation on 1nc.-Pittsburgh, PA Control Concepts Corporation-Beaver, Corporation-Beaver, PA Cutler-Hammer, Cutler-Hamm er, Inc.-Milwaukee, Inc.-Milwaukee, WI Cyberex, Inc.-Mentor, Inc.-Mentor, OH Eaton Corporati Corporation-Cu on-Cutler tler Hammer-Milwau Hammer-Milwaukee, kee, WI Echelon-Palo Alto, CA Electrica Elec tricall Power Systems, Inc.-Tulsa, OK Electro Switch Corporation-Weymouth, MA Elliott Control Company-Hollister, CA Emerson Electric Company-Grand Island, NY
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NEMA 250-1997
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Entrel ec, Inc-Irving, TX Entrelec, Firetrol, Firet rol, Inc. -Car y, NC GE-Plainville, CT General Gene ral Equipment Equ ipment & Mfg. Co., Co., Inc.-Loui Inc.-Louisvill sville, e, Gettys Corporation-Amherst, Corporation-Amhers t, NY Gidding Gidd ings s & Lewis, 1nc 1nc..-Fo Fond nd Du Lac, WI Hamischfeger Hamischfeg er Corportion-Milw Corportion-Milwaukee, aukee, W I Honeywell IA IADD- Ft Ft.. Washi Washington ngton,, PA PA Hubbell IncorporateckMadison, OH Joslyn Clark Controls, Inc.-lancaste Inc.-lancaster, r, SC
KY
Killark Kil lark Electri Ele ctric c Mfg. Company-S Company-St. t. Louis, MO Klo ckner-Moe Klockne r-Moeller ller Corporation-Franklin, MA Lexington Switch & Cont rotMa diso n, OH OH MagneTek, MagneT ek, Inc. Inc.-Ne -New w Berlin, Berlin , WI Master Mast er Control Contro l Systems, System s, Inc.-La Inc.-Lake ke Bluff, IL Metron, Metr on, Inc.-Denver, CO Micro Switch-Freepor Switch-Freeport, t, IL 0 - Z Gedneyíünit Of General General Signal Corporation-Tulsa, OK Omron Electroni Elec tronics, cs, Inc.-Schaum Inc.-Schaumburg, burg, IL Onan Corporation-Minneapolis, MN Pepperl + Fuchs Fuchs,, Inc.-Twinsburg, Inc.-Twinsburg, OH Phoenix Phoeni x Contact, Inc.-Har Inc.-Harrisbu risburg, rg, PA R Stah Stahl, l, Inc.-Woburn Inc.-Woburn,, MA Reliance Electric Co./Rockwell Automation-Euclid Automation-Euclid,, Rittal Corporation-Springfield, OH Robicon-New Kensington, PA
OH
Rockwel l Automation-Mi Rockwell Automation-Milwaukee, lwaukee, WI Russel Rus selectr ectric, ic, Inc.-Hingh Inc.-Hingham, am, MA Siemens Energy & Automation, Automati on, Inc.-Alph Inc.-Alpharet aretta, ta, GA Siemens-Fumas Siemens-Fu mas Controls-Batav Controls-Batavia, ia, IL Sprecherr & Schuh, Inc.-Hous Spreche Inc.-Houston. ton. TX Square D Company-Lexington, KY Texas Instruments, Inc.-Dallas, TX Toshiba Intemational Intematio nal Corporation-H Corporation-Houston, ouston, TX Turck, Inc.-Minneapolis, MN WAG0 WA G0 Corporation-Brown Deer, WI Yaskawa Yaskaw a Electri Ele ctric c America, Inc.-Nor Inc.-Northbr thbrook, ook, IL Zenith Zenit h Control Controls, s, I ncorporated-Chi ncorpora ted-Chicago, cago, L
MOLûED CASE BREAKER SECTION ABB Control, Control , Inc.-Wichita Falls, TX America n Circuit American Circ uit Brea Breaker ker Corp.-Albe Corp.-Albemarl marle, e, NC GE-Farmington, CT Cutler-Hammer CutlerHammer Inc.-Piitsburgh, PA Klockner-Moeller Klockner-Mo eller Cotporation-F Cotporation-Franklin ranklin,, MA Siemens Energy Automation, Automati on, Inc.-Norc Inc.-Norcross ross,, GA SPD Technologies-Philadelphia, PA Square Squar e D Company-C Compa ny-Ceda edarr Rapids, Rapids, IA Thomas & Be Betts tts Corporation-Memphis, TN CONDUïï COND Uïï FITTINGS FITTINGS SECTION
Adalet-Plm-Cleveland,OH Applet App leton on Electric Electric Company-Ch Co mpany-Chicago, icago, IL Arlington Industries, Industries, Inc.-Scra Inc.- Scranto nton, n, PA Brid idg geport F ~ n g s ,nc.-Bridgeport, nc.-Bridgeport, CT Crouse Crous e Hinds Division-Syracuse, NY Erico, Inc.-Solon, OH Halex Company Company,, The- Clevel Cle veland and,, OH Hubbell Incorporated-Bridgeport, CT
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NEMA 250-1997
Page v Killark Electric Mfg. Comp Company-S any-Stt Louis, MO Minerallac Compa Company-Ad ny-Addison dison,, IL Myers Electri Electric c Products, Inc. Inc.-Full -Fullerto erton, n, CA Neer ManufacturingCom Compan pany, y, In Inc.-Le c.-Lexing xington, ton, OH 0-Z edney-Tenyville, CT Pass & Seymour/Legrand-Syracuse, NY Producto Electric Corporation-Orangeburg, NY . Progressive Progres sive Machin Machine e Die, Inc.-W Inc.-Walt alton on Hills Hills,, OH Raco, Inc.-South Bend, IN Red Dot Dot Div isi oMo sto n, MA Regal Manufacturing-Industry, CA Steel City-Memphis, TN Steell Electri Stee Electric c Product Products s Co, Inc.-B Inc.-Broo rookly klyn, n, NY The Halex Company-Clevel Company-Cleveland, and, OH Thepitt The pitt Manufac Man ufacturi turing ng Co. Co.,, 1nc. 1nc.-Mea eado dow w Lands Lands,, PA Thomas Betts Be tts Corporation-Mem Corporation-Memphis, phis, TN
SWITCH SECTION American Circ Circuit uit Breaker CorpCorp-Albem Albemarle, arle, NC Boltswit Bolt switch, ch, Inc.-C Inc .-C tystal tys tal Lake Lake,, IL Bussmann Div/Cooper Industries-St. Louis, MO CutlerCut ler-Ham Hammer mer Inc.-Pittsb Inc.-Pittsburgh, urgh, PA GE-Plainville, CT Hubbell Incorporated-Bridgeport, CT Pringle Pringl e Ele Electri ctrical cal Mfg. Co., The-Fo The-Fort rt Washin Washington, gton, P PA A Siemens Sieme ns Ene Energy rgy Automa Automation, tion, Inc.Inc.-Norcr Norcross, oss, GA Square D Company-Lexington, KY Test SwitchTechnolo Technology, gy, Inc.Inc.-Canto Canton, n, OH Thomas Bet Betts ts Corporation-Me Corporation-Memphis, mphis, TN
PANELBOARD PANE LBOARDAND DISTRIBUTION DISTRIBUTIONBOARD BOARD SECTION American Circ Circuit uit Breake Breakerr Cor Corp.p.-Alb Albema emarle rle,, NC B-Line B-L ine S Systems ystems,, 1nc 1nc.-P .-Port ortland land,, OR Lamson Lam son Sessio Sessions ns Company-Cleve Company-Cleveland, land, OH Curren Cur rentt Techn Technolog ology, y, Inc.-Irving, Inc.-Irving, TX Cutler-Hamm Cutle r-Hammer er Inc.-Pittsbu Inc.-Pittsburgh, rgh, PA GE-Plainville, CT Hubbell Incorporated-Bridgeport, CT Milbank Milban k Manufac Manufacturing turing Compa Company-Ka ny-Kansas nsas City, MO Penn Panel Box Company-C Company-Collingd ollingdale, ale, PA Pnngle Electri Electrical cal Mfg. Co., Th The-F e-Fort ort Washin Washington, gton, P PA A Siemens Energy 8 Automat Automation, ion, Inc.-G Inc .-Gra rand nd Prairie, TX Square Company-Lexington, K YMO The DurD Durham ham Comp Company-L any-Leban ebanon, on, Thomas & Bett Betts s Corporation-Me Corporation-Memphis, mphis, TN
PIN 81SLEEVE PLUG, PLUG, RECEPT RECEPTACL ACLE E& CONNECTORSECTION Adalet-Plm-Cleveland, OH Adalet-Plm-Cleveland, Appleto Appl eton n Electric Company-Chica Company-Chicago, go, IL Arrow Hart Wiring Devicec-Syracuse, Devicec-S yracuse, NY Bryantt Elect Bryan Electric, ric, Inc.Inc.-Milfor Milford, d, CT Crouce Hinds Divi Division sion-Syra -Syracuse cuse,, NY Hubbell Incorporated-Bridgeport, CT Joy Molded Rubber ProdJDiv. of Cooperr Industries-L Coope Industries-Lagrange, agrange, NC Kil Killark lark Electri Electric c Mfg. Compa Company-St ny-St Louis, MO Meltric Corporati Corporation-Cudahy on-Cudahy,, WI
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NEMA 250-1997 Page vi
Pass & SeymouriLegrand-Syracuse, R Stahl Stahl,, Inc.-Woburn, Inc.-Woburn, MA
NY
-
Thomas & Betts MIPCO-Brooksville, FL Thomas & Betts Corporation-Memph Corporation-Memphis, is, TN W. W.T. T. Store Sto rey y Inc.-Dalmati Inc.-Dalmatia, a, PA
STEEL RIGID CONDUIT & ELEC. METALLICTUBING SECTION Allied Tube Condui Conduitt Corporation-Harvey Corporation-Harvey,, IL Conduit Pipe Products-Westerville, OH LTV LTV Steel Tubular Products Co.-Young Co.-Youngstow stown, n, OH OCAL, Inc.-Van Inc.-Van Nuys, Nuys, CA Perma-Cote Industries-Uni Industri es-Uniontown, ontown, PA Picoma Industries, Indust ries, Inc.-Waynesboro, Inc.-Waynesboro, PA Robroy Industri Indu stries, es, Inc.-V Inc.-Vero erona, na, PA Shamrock Conduit Products, Inc.-Barnesville, Inc.-Barnesville, OH Western Tube & Condui Conduitt Corp.-Lon Corp.-Long g Beach, CA Wheatl Whe atland and Tube Compa Company-Col ny-Collings lingswood, wood, NJ WIRING DEVICE SECTION AMP Incorporated-Harrisburg, PA Arrow Arro w Har Hartt Wiring Devices-Syracuse, Devices-Syracuse, NY Bryant Electric, Elec tric, Inc.-Milfor Inc.-Milford, d, CT Carlon Car lon Electric Electrical al Productc Productc-Clev -Cleveland eland,, OH Daniel Woodhead Company-Northbrook Company-Northbrook,, I L Eagle Electric Electri c Mfg. Company, Inc.-Long Inc.-Long Island Isl and City, NY Ericson Manufacturing Company -Willoughby, -Willoughby, OH GE-Warwick, R I Hubbell Incorporated-Bridgeport, CT Leviton Manufacturing Manufac turing Company, Inc.-Little Inc.-Little Neck, NY Lutron Electronics Company, Company, Inc.-Co Inc .-Coope opersb rsburg urg,, PA Marinco/Marine Industries Industri es Company-N Company-Napa, apa, CA McGill Electrical Electri cal Product Group-Valparaiso, Group-Valparaiso, IN MYTECH Corporation-Austin, Corporation-Austin, TX Pass & SeymourAegrand-Syracuse,NY Steel City-Memphis, TN Technol Tec hnology ogy Research Research Corporation-Cl Corporati on-Clearwa earwater, ter, FL The Wiremold Company-West Company-West Hartford, UNENCO Servic Services, es, Inc.-Alameda, Inc.-Alameda, CA Watt Stopper, Inc, The-Can The-Canta ta Clara, CA Wiremo Wir emoid id Compan Company, y, T h e W e s t Hartfor Hartford, d, CT ELECTRICAL MEASURING EQUIPMENT SECTION ABB Power Powe r T D Company Compa ny Inc.-Raleigh, NC APTECH, Inc.-Charlotte, NC B-Line Systems, Inc.-Portland, Inc.-Portland, OR GE-Somersworth, NH Meter Met er Devices Company, Company, Inc.-C Inc .-Cant anton, on, OH Milba Milbank nk Man Manufact ufacturing uringComp Co mpan anyK yKan ansa sas s City, MO Siemens Energy & Automa Automation, tion, Inc.-Norcross, Inc.-Norcross, GA Square D Company-Lexington, Company-Lexington, KY The Durham Durha m Company-Lebanon, MO Thomas & Betts Corporation-Memph Corporation-Memphis, is, TN
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Section 1 1.1
GENERAL
SCOPE
This standard stan dard covers enclosures en closures for electrical equipment rated not more than 1000 Volts and intended to be installe i nstalled d and used as follow follows: s: a.
Non-hazardous locations 1. Enclosur Enclosures es for indoor locations, locations, Types Types 1,2,5, 1,2 ,5, 12, 12K , and 13; 13; and and 2.
b.
Enclosures for indoor or outdoor locations, locations, Types 3,3R, S, ,4X, 6, and 6P.
Hazardous locations locatio ns 1. Enclosures for indoor locations, Types 7 and 9; 2. Enclosures for indoor or outdoor locations, Type 8; and Enclosures sures for mining applications, applications, Type 10. 3. Enclo
Requirements for enclosures for non-hazardous locations are contained in the body of the standard. Requirements for enclosures for hazardous locations are contained in Supplement A of the standard. This standard stand ard covers the requirements to provide pro vide protection to the enclosed equipment against specific environmental conditions. This standard standa rd supplements requirements requiremen ts for enclosures that are contained in the individual product standards. This standard stan dard does not cover the requirements requirements for protection of of devices against against conditions such as condensation, icing, corrosion, or contamination which may occur occur within the enclosure or which may enter via conduit or unsealed openings. openings.
A product that contains conta ins features, characteristics, components, components, materials, materials, or systems new or different
from those those in use when the standard was was developed, developed, and that involves a risk of of fire, electric shock, or injury to persons shall shal l be evaluated eva luated using the appropriate approp riate additional component and end-product requirements as determine de termined d necessary necessary to maintain the level of safety for the user of of the product as as originally anticipated by the intent of this standard. 1.2
REFERENCES
The following publications are adopted in part, by reference in this publication, and are available from the organizations organ izations below. 1.2. 1.2.1 1
Normativ Norm ativ e References References
The following followin g normative documents contain provisions, provisions, which which through reference in this text, constitute c onstitute provisions of this Standards Publication. Publication . By reference herein these these publications are are adopted, in whole or in part as indicated, in this SP.
American Americ an National Standards Insti tut e ((ANS ANSI) I) 11 West West 42nd St Street reet New York, NY 10036 American Society of Mechani Mechanical cal Engineers Eng ineers (ASME) (ASME) 345 East 47th Street New York, NY 1O017-2392 7-2392 ANWASME 81.20.1 ANSVASME 894.1 1M
Pipe Threads, General Purpose inch) Twis t Drills Drills
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Americ an Society fo r Testi ng and Materials (ASTM (ASTM)) 1O0 Barr Harbor Drive West Conshohocken. PA PA 19428 1942 8
ASTM A 6531A 653M ASTM B117 ASTM B555 ASTM ES27 0471 ASTM
Standard Specificationfor Steel Sheet Sheet,, Zinc-Coated Galvanized)or ZincIron Alloy-Coated Galvannealed)by Galvannealed)by the Hot-Dip Hot -Dip Process Salt Fog Testing Standard Standa rd Guide for Measurement Measurement of Electrodepo Electr odeposited sited Metallic Metalli c Coating Thickness Thickne ssby tthe he Dropping Test P
ßubber Establishing ope@-€ ffect of Liquids ßubber-Establis ßubberhing Replacement Replaceme nt Immersion Reference Referen ce Oils for ASTM No. and No. 3 mmersion Oils Used in Test Method 0471 04 71 Internation al E Electrotechnical lectrotechnical Commission (IEC) 3, rue de Varembé Varembé P.O. Box 131 1211 121 1 Geneva 20 Switzerland
IEC 529
Degrees of protection protect ion provided provide d by enclosures enclosures IP Code) National Electric al Manufacturers Manufacturers As sociation (N (NE EMA) 1300 North 17th 17t h Stree Street, t, Suite 1847 1847 Rosslyn,, VA 22209 Rosslyn 22209 National Natio nal Fire Protecti on Assoc iation (NFP (NFPA) A) 1 Batterymarch Park PO Box 9101 Quincy, MA MA 02269
ANSIMFPA 70 ANSIMFPA 496 ANSIMFPA 497M
National Electrical Code Purged and Pressurized Press urized Enclosures Enclosures for Ele Electrical ctrical Equipment Classification Classific ation of Gases, Vapors Vapors and Dust for Electric Elec trical al Equipment in Hazardous Classified)Locations Classified)Locations Superintendent of Documents US Government Printing Office Washington, DC 20402
30 CFR Part 18
Electric Motor-Driven Mine Equipmen Equipmentt and Accessories Underwrit Unde rwrit ers Laboratories Inc. (UL) 333 Pfingsten Road Northbrook, Northbroo k, IL 60062
ANSIAJL 50 ANSIIUL 94 ANSVUL 514B ANSVUL ANSVUL 698 ANSINL ANSIN L 74 66 ANSINL 877 ANSINL 886 ANSVUL 894
Enclosures for Electrical Enclosures Electri cal Equipment Equipment Tests for for Flammabili Fla mmability ty of Plastics Plas tics Materials for Parts in Devices and Appliance Fittings for Conduit and Outlet Boxes Boxes Industrial Industri al Control Equipment for Use in Hazardous Classified) Classifi ed) Locations Locatio ns Pol’eric Materia Mat erials ls Use in Electri Ele ctrical cal Equipment Evalua Evaluation tions s Circuit Circ uit Breakers Breakers and Circuit-B Ci rcuit-Breaker reaker Enclosures Enclosures for f or Use in Hazardous Classified)Locations Outlet Boxes and Fittings for Use in Hazardous Hazardous Classified) Classifie d) Locations Locatio ns Switches Switche s for Use in Hazardous Hazardous Classified) Classifie d) Locatio Locations ns
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ANSIíüL 1332
1.3
Organic Coatings for Steel Enclosure for Oufdoor UseElecfrical Equipment
DEFINiTIONS The following definitions are applicable in this standard.
Cover: An unhinged portion of an enclosure that covers an opening. Degree of Protection: The extent of protection provided by an enclosure against against access to hazardous parts, against ingress of of fforeign oreign solid objects and/or against against ingress of water and verified verifie d by standardized test methods. Design les ts : Tests to demonstrate performance of of a product designed to applicable standards. N ote: D esign tests are not inten ded to b e production tests.) Door: A hinged hinge d portion o off an enclosure that covers an opening. opening. surroundin g case constructed to provide a degree of protection to personnel against Enclosure: A surrounding incidental inciden tal contact with the enclosed enclose d equipment and to provide a degree of protection to the enclosed en closed equipment against specified environmental en vironmental conditions. Hazardous (Classifi ed) Locations: Areas which may contain hazardous (classified) materials in Hazardous sufficient quantity to create an explosion. (See Article 500 50 0 of the National Electrical Code. Code.)) Hazardous Ha zardous (Classif (Classif ied) Ma Materiais: teriais: Gases, vapors, combustible dusts, fibers, or flyings which are explosive under certain conditions. incidental Contact: Accidental or unintentional contact. contact. protec ted from from exposure to the th e weather. weather. indoor Locations: Areas which are protected Knockout: A portion of the wall wa ll o off an enclosure enclosure so fashioned that it ma may y be removed readily by a hammer, screw- driver, and pliers at the time of installation install ation n order to provide a hole for the attachment attach ment o off an auxiliary auxili ary device or raceway, cable, cable, or fitting. (classified) materials in sufficient Non Hazardous Hazardous Loc ations: Areas which do not contain hazardous (classified) quantity to create an explosion. Nonventiiated: Constructed so as to provide no intentional circulation of extemal air through the enclosure. Oii-Resist Oii-Re sist ant Ga Gaskets: skets: Gaskets made of of material which which is resistant to oil o il and oil oi l fumes. fumes. exposed to the weather. Outdoor Locations: Areas which are exposed of external air through the enclosure e nclosure to Ventilated: Constructed so as to provide for the circulation of remove excess heat, fume fumes, s, or vapors. vapors.
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NEMA 250-1997 Page 5
Section 2
ENCLOSURE TYPES, FEATURES, AND APPLICATIONS 2.1
GENERAL
The features of each enclosure Type Type are applicable only when when the enclosure is completely and properly installed.
All mechanical and electrical parts mounted on or through an enclosure shall pass the applicable tests
for the enclosure Type unless otherwise specified. 2.2
SPECIFIC TYPES
Table 2-1 and Table 2-2 are guides for comparing specific applications app lications of enclosures. The specific enclosure Types, Types, their th eir applications, applicati ons, and the environmental conditions they are designed to protect against are as follows: Type 1 Enclosures constructed for indoor use to provide a degree deg ree of of protection to personnel perso nnel against incidental contact with with the enclosed equipme equipment nt and to provide a degree of protection against falling dirt. Type 2 - Enclosures constructed for indoor use to provide prov ide a degree of of protection to personnel perso nnel against incidental contact with the enclosed enclo sed equipme equipment, nt, to provide prov ide a degree of of protection against falling dirt, and to provide a degree of protection against dripping and light splashing of of liq liquids. uids. Type 3 - Enclosures constructed for either indoor in door or outdoor outdo or use to provide a degree of protection pro tection to personnell against incidental contact with the enclosed personne enclose d equipment; to provide provi de a degree of protection pr otection against falling dirt, rain, sleet, snow, and windblown dust; and that will be b e undamaged by the extemal formation of ice on the enclosure. Type 3R - Enclosures constructed for either indoor in door or outdoor o utdoor use to provide prov ide a degree of of protection to personnell against incidental contact with the enclosed personne enclo sed equipment; equipment; to provide a degree of protection protectio n against falling dirt, rain, sleet, and snow; snow; and that will wi ll be undamaged by the external ex ternal formation of ice on the enclosure.
-
Type 3s Enclosures constructed for either indoor ind oor or outdoor o utdoor use to provide pro vide a degree of of protection p rotection to personnel against incidental contact with the enclosed equipment; to pr provide ovide a degree of of protection against falling dirt, rain, sleet, snow, and windblown dust; and iin n which which the external mechanism(s) remain operable when ice laden.
-
Type 4 Enclosures constructed for either indoor ind oor or outdoor outdo or use to provide provid e a degree of of protection to personnell against incidental contact with the enclosed personne en closed equipment; to provide pro vide a degree of protection protectio n against falling dirt, rain, sleet, snow, windblown windblown dust, splashing sp lashing water, water, and hose-directed hose-di rected water, and that will be undamaged undamaged by the external externa l formation of of ice on the th e enclosure. Type 4 X - Enclo Enclosures sures constructed constructed for either indoor or outdoor use to provide a degree degree of protection to personnel against incidental incid ental contact with the enclosed equipment; to provide prov ide a degree o off protection against falling dirt, rain, sleet, snow, windblown dust, splashing water, hose-directed hose-dire cted water, and corrosion; and that will be undamaged by the external formation formati on of ice ic e on the enclosure. Type 5 - Enclosures constructed for indoor ind oor use to pro provide vide a degree of protec p rotection tion to personnel personne l against incidental contact with the enclosed enclos ed equipme equipment; nt; to provide prov ide a degree of protect pr otection ion against falling fallin g dirt; against settling airborne dust, lint, fibers, and flyings; a and nd to provide a degree of protection against dripping and light splashing of liquids.
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1997
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9
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Type 6 Enclosur Enclosures es constructed for e either ither ind indoor oor or outdoor use to provid provide e a degree of protection o personnelagainst incide incidental ntal contact with the th e en enclosed closed equipment; to provide a degree of protection against again st falling dirt; against ho hosedi sedirect rected ed water a and nd the en entry try of water during occasional temporary submersi subm ersion on at a limite limited d depth depth;; and that will b be e undamaged by the e extemal xtemal formation of ice on the enclosure. Type 6P - Enclosures constructed for either indoor or outd outdoor oor use to provide a degree of protection to personnel against incide incidental ntal contact with th the e enc enclosed losed equipment; to provide a degree of protection against again st falling dirt; against hose-directed water and the th e entry of water during prolonged submersion at a limited depth depth;; and that wi will ll be undamaged by the external exte rnal formation o off ice on the enclosur enclosure. e. Type 12 - Enclosures constructed (without knockou knockouts) ts) for indoor use to provide a degree of p protection rotection to personnelagainst incident incidental al contact with th the e en enclosed closed equipment; to provide a degree of protection against again st falling dirt; against circulatin circulating g dust, lint, fibers, and flyings; and against dripping and light splashing of liquids.
-
Type 12K Enclosure Enclosures s constructed (with knockou knockouts) ts) for indoor in door use to provide a degree of protection to personnelagainst incident incidental al contact with the e enclose nclosed d equipme equipment; nt; to provide a degree of protection against agai nst falling dirt; against circulating dust, lin lint, t, fibers, and flyings; and against dripping and light ligh t splashing of liquids. Type 13 - Enclosures constructed for indo indoor or use to provide a degree of p protection rotection to p personnel ersonnel against incidental contact with the enclose enclosed d equipment; to provid provide e a degree o off protection against falling dirt: against agai nst circulating d dust, ust, lint, fibers, and flyings; and ag against ainst the spraying, splashing, and seepage of water, oil, and no noncorrosive ncorrosive coolants. coolants.
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S T D N E M A i50-ENGL
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b470247 0 5 L b 4 7 0 0 0 8
NEMA 250-1997 Page 7
Table 2-1 Compa Co mparison rison of Specific Specific Applications Appl ications o f Enclosures for Indoor Nonhazardous Locations Type of Enclosure
Provides a Degreeof Protectio Protection nAgainst th the e Following Environmental Environ mentalConditions
1'
Incidental contact with the enclosed equipment equipment
x
Falling dirt
4
4X
5
6
6P
12
12K
13
x
x
x
x
x
x
x
x
x
x ...
x x
x x
x x
x x
x x
x x
x x
x x
x x
Settling Settlin g airborne dust, dust, lint, fibers, and flyings **
...
...
x x
x x
x
..
x ...
x
...
x x
x
Hosedown and splashing splashin g wat water er
x x
Oil or coolant spraying and splashing
...
...
...
...
...
...
... ...
... ...
Occasional temporary submersion Occasional prolonged prolong ed submersion
...
... ...
... ... ... ...
...
Corrosive agents
...
...
...
...
Falling liquids and light splashing
2
Circulating dust, lint, fibers, and flyings **
Oil and coolant seepage
................................................................ ............................................................ ...........................
**
... ... ...
x ... ...
... ...
x x x
...
...
...
...
...
x
... ...
...
These endosu endosures res may may be ventilated. 111
Class and lyings fibers Thes These e fibers nonhazardous considered ignitable or combustible are notsee are andflyings typ Code, flyings. For Class type ignitable fibers or materials combustible the National Article Electrical 500.
Table 2-2 Comparison of Specific Applications of Enclosures f or Outdoor Nonhazardous Locations Type of Enclosure
Provid es a Degreeof Protectio Provides Protection n Against the Following EnvironmentalConditions
3
3R* 3R*
3s
4
4x
6
6P
Incidental contact with the enclosed equipm equipment ent
X
X
X
X
X
X
X
X
X
X
X
X
X
...
...
Rain, snow, and sleet ** Sleet *** ................................................................. ........................ Windblown dust, lint, fibers, and flyings
X........................ ... ... ............. ................. .......................... ......................... ............ ......................... ..........
Hosedown Corrosiveagents .........................................
................................. ............................... ..............
X
... ...
... 1
... ........
................................
...................
X
...
X
X
X
X
X
X
X
X
...
...
...
X
...
X
...
...
...
...
...
X
Occasional temporary submersion Occasional prolonged prolong ed submersion
...
These enclosures may be ventilated. ventilated. hen n the enclosure s ice ice covered. covered. External operating mechanisms are not required to be operable whe nisms are operable when the e enclosur nclosure e is ice covered. See 5.6. *** External operating mechanisms
**
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Page 9
Section 3
3.1
CONSTRUCTION
GENERAL
The construction constructio n requirements n this Standard are supplemental supplementalto the construction requirements n the individual product standards. standards. In cases of conflict the product standards shall shall take precedence. UNITS OF MEASUREMENT
3.2
Unless noted otherwise the the first units of measur measurement ement shown in this standard standa rd are metric metr ic units. These measurements are normally n ormally followed by an English unit of measurement measurement in parenthesis. pare nthesis. The units of measurement measurement are intended as alternative measuremen measurements ts and are not inten i ntended ded to be exact conversions. 3.3
MATERIALS
- GENERAL
Enclosures shall be made of metal or polymeric polymer ic materials w which hich meet the requirements requi rements of 3.4. 3.4
MATERIALS
- POLYMERIC
A polymeric enclosure or a polymeric part of an enclosure necessaiy to maintain he integrity integ rity of an
electrical enclos enclosure, ure, shall comply with the applicable requirements requirements n the UL Standardfor Polymeric Materials - Use in Elect Electrical rical Equipment Evaluat Evaluations, ions, UL 746C and also with any additional requirements specified in i n this Standa Standard. rd. A for polymeric plug orofother closure made oParts f a material classed accordance with UL Standard Standar d for Tests Flammability Plastic Pl astic Material Materia l or of in Devices Devices andin Applianc App liances, es, UL 94 the is acceptable acceptab le under any one of the following conditions: Not more than 650 65 0 mm2 (1 in2) n area and is: 1. Cla Classe ssed d as 94-5VA, 94-5VA, 94-5VB, 94-5VB, 94V-O, 94V-O, 94V-1, or 94\11-23 23 or Classed as 94HB 94H B and complies comp lies with the Flammability Flammabi lity 127 mm mm (5 inch) test in i n the UL 2. Standard for Pty P tyme meri ric c Materials Use in Electrical Equipment Evaluations, UL 746C. b. More than 650 mm (1 in2) n area and is: 1. Classed as 94-5VA 94-5VA or'94-5VB or'94-5V B and complies complies with the Resistance Re sistance to Impact (normal (norma l and cold) test in the UL Standard for Polymeric Materials Materials - Use in Electrical Equipment Evaluations, UL 746C; or 94V-O, O, 94V-II94 94V- II94V-2 V-2,, or 94HB 94HB and and complies with the Flammability Flamm ability 127 mm (5 2. Classed as 94Vinch) Flame and the resistanceto Impact Impact (normal and cold) test in the UL Standard for Polymeric Materials Use in Electrical Electri cal Equipment Equipment Evaluations, UL 746C.
a.
3.5
CORROSION PROTECTION
- GENERAL
Enclosures shall not be constructed of metals in any any combination such as to cause galva galvanic nic action which will adversely affect any part of the equipment exposed to moisture. Copper,, bronze, brass containing Copper containing at least 80 percent percent copper, stainless steel, or aluminum may be used without additional protection against corrosion. Hinges and other attachments used on an enclosureshall be resistant to corrosion and shall s hall comply with the same same requirementsas the enclosure. 3.5.1
Indoor Corrosion Corrosion Protecti on
Both the inside and outside surfaces of an enclosure made of of ferrous fe rrous material shall be protec p rotected ted against corro c orrosion sion by enameling, enameling, galvanizing galvanizing,, or other equivalent means. means. Types 1,2, 5, 12, 12K, nd 13
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ferrous enclosures, and external ferrous parts attached attached to these enclosure Types Types and not protected p rotected by
one of these means shall be tested as described in 5.8. 3.5 3.5.2
Outdoor Outdo or Corros ion Protect Protection ion
Types 3,3R, 3,3 R, 3S 3S,, 4,4X, 4, 4X, 6, and 6P ferrous ferrous enclosures, and extemal ferrous parts par ts attached to these enclosure Types, Types, shall shal l be protected against corrosion by one of the coatings or finishes finis hes in 3.5. 5.2. 2.1 through 3.5.2.5. 3.5.2. 3.5 .2.1 1
Galvan Gal van ized G90
Hot-dipped mill-galvanized sheet sheet steel conforming conforming with the coating Designation G90 in Table I of ASTM Designation ASTM Designatio n A653lA653M-95. A653lA653M-95. 3. 3.5. 5.2. 2.2 2
Zinc Zin c Coating Coati ng
A zinc coating, other than that provided on hot- dipped mill-galvanized sheet steel, uniformly applied to
an average thickness of not less than 0.015 0.015 mm (0.00061 (0.00061 inch) in ch) on each surface with a minimum mini mum thickness of 0.014 mm (0.00054 inch). The thickness thickness of coating shall be established by the metallicmetall iccoating-thickness coating-thick ness test described in ASTM ASTM B555. An annealed coating coat ing shall shall comply with with 3.5.3. 3.52.3 3.5 2.3
Zinc Coating wi with th Paint Paint
A zinc coating coat ing conformi conf orming ng with 3. 3.5. 5.2. 2.3. 3.1 1 or 3.5 3.5.2.3.2 and with one coat coa t of an organic orga nic finis fin ish h of the
epoxy or alkyd-resin type or other outdoor paint applied after forming on each surface. The acceptability of the paint may be b e determined by consideration conside ration of of its composition or by corrosion tests if these are considered necessary. 3. 3.5.2 5.2.3 .3.1 .1 Galv Galvani anized zed G60 Hot-dipped mill-galvanized mill-galvanized sheet steel conforming conforming with with the coating Designation G60 or A60 in Table I of ASTM Designation De signation A653lA653M-95. 3.5. 3.5.2. 2.3. 3.2 2
Zin Zinc c Coating Coati ng ot other her than th an Galvani zed
on hot- dipped dipped mill-galvanized sheet steel, uniformly applied to A zinc coating, other than that provided on an average thickness of not less than 0.01 0.010 0 mm (0. (0.0004 00041 1 inch) on each surface with wit h a minimum thickness of 0.009 mm (0.00034 inch) inch).. The thickness thickness of of the coating shall be established by the metalliccoating-thickness coating-thi ckness test described in i n ASTM ASTM 8555.
3.5.2.4
Paint
Paint may be accepted accepted when when the applicable requirem requirements ents for Organic Coatings for Steel Enclosures for Outdoor Use Electrical Elect rical Equipment, Equipment, UL 1332, indicate that it provides equivalent protection. 3. 3.5. 5.2. 2.5 5
Ot Other her Finis Fin is hes
3. 3.5. 5.3 3
Annealed An nealed Coating Coati ng
All other finishes shall shal l comply with 5.9.
An annealed coating on sheet steel that is bent or similarly formed or extruded or rolled at edges of holes after after annealing shall be additionally painted painted in the affected area if the process damages the zinc coating. 3.5.4
Bends and Forms on Zinc Coatings
If flaking or cracking of of the zinc zinc coating at the outside radius radius of of the bent or formed section is visible at
25 power magnification, magnifica tion, the zinc coating is considered to be damaged. damaged. Simple sheared or cut cu t edges and punched holes are not required to be additionally additionall y protected.
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NEMA 250-1 250-1997 997
Page 11
3.5. 3.5.5 5
Hot Ripp Ripped ed Galvani Galvanized zed Damage
A hot-dipped mill-galvanized G90 coating shall not be damaged during handling or fabrication to the
extent that the base metal is exposed.
Exception No. 1 Uncoated cross-sectional surfaces at cut edges and dril drilled led openings are acceptable. Exception No. 2: The base metal may be exposed exposed if (1) the maximum maximum width and length le ngth of of tthe he exposed metal me tal does not exceed the thickness and length of of any cut edge on the sheet or (2) the surface has one coat of an organic finish of the epoxy or alkyd-resin a lkyd-resin type, type, or other outdoor paint applied after fabrication. Sheet steel ste el that employs a hotd ho tdip ippe ped d mill-galvanized G90 coating that is drawn, formed, formed, extruded, or rolled shall be additionally painted with one coat of an organic organic finish of of the epoxy or alkyd-resin type or or other outdoor outdo or paint in i n the areas that are affected by b y a process that damages the coating coatin g as determined by the requir requirement ement in 3.5.4. 3.5. 3.5.6 6
Cast ir on
An enclosure of cast iron or malleable iron at least 3.2 mm (1/8 inch) thick shall be protected against corrosion by (1) a 0.0038 mm (0.00015 inch) thick coating of of zinc, zinc, cadmium, cadmium, or the equivalent, on the outside outsid e surface and a visible visibl e coating of such metal on the inside surf surface, ace, or (2) one coat of an organic finish fini sh of the epoxy of alkyd-resin type or other outdoor paint on each surface. surface. The acceptability of of th the e paint may be determi determined ned by consideration consideration of its composition or, if neces necessary sary,, by the corrosion tests specifi spe cified ed in 5.9. 5.9. 3.5.7 Type 4 X Corrosion Protection Type 4X enclosures, and extemal ext emal parts attached to these enclosures, enclosures, shall be manufactured manu factured of Amencan Amenc an Iron an and d Steel Institute AISI) Type 304 Stainless steel, steel, polymencs, or materials mate rials with equivalent corrosion corros ion resistance. If material other than Type 304 Stainless Steel Steel is used it shall be tested in accordance accordan ce with 5.9 and 5.10. 3.6
OPENINGS
Openings provided in an enclosure shall comply with the tests tests for the enclosure type with the openings op enings unfilled except that openings in accordance with 3.6.1, if provided in the test te st enclosure, shall be filled to maintain the environmental en vironmental integrity of of the enclosure. 3.6. 3.6.1 1
Equipment Equipm ent Openings
All enclosures may be provided with openings intended o be closed at insta installation llation by equipment. Such openings shall comply with the performance requirements requirements in this standard and with the requirements in the appropriate app ropriate end product standard when the intended intende d equipment equipment is installed. See 4.6. 3.6.2
Ventilation
Type 1,2, and 3R enclosures may be ventilated. 3.6. 3.6.3 3
Drainag Drainage e Openings Openi ngs
Type 2 and 3R enclosures shall have provisions for drainage. drainage. Drainage openings shall not be less than 3.2 mm in diameter (1/8 inch in diameter) or more than 6.4 mm in diameter (1/4 inch in diameter) diameter) unless baffled baffl ed or provided provid ed with a drainage draina ge fitting. For Type 2 and 3R enclosures that also meet the requirements requirements of other enclosure en closure types, types, the drainage draina ge openings shall be closed close d by a removable plug. The enclosure shall meet the requirements of of th the e other othe r enclosure types with the plug installed. See 4.7.
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S T D - N E M A 250-EMGL
Page 12
3.7
MOUNTING
3997
6470247 0536494 7 5 3
M
If mounting means are provided for Types 3,3S, 4,4X, 6,6P, 12,12K and 13 these means means shall be external to the equipment equipment cavity. cavity. 3.8
CONDUIT CONNECTION
Enclosures shall be designed for use with appropriate condu conductor ctor entty provisions to maintain the specified environmental capability after proper installation. 3.9
HUBS AND FITTINGS FITTIN GS
A conduit hub or fitting may be shipped separateiy if the necessary hardware, gaskets, and
instructions are provided either with the enclosure o orr the fitt fitting. ing.
An enclosure provided without conduit hubs shall be mark marked ed iin n accordance with 4.5.
3.10
KNOCKOUTS
All enclosure types except Type 12 shall be permitted to have knockouts. When knockouts are provided, dimensions should be as shown in Table 3-1. Knockouts shall meet the appropriate design tests for the enclosure Type in which they are provided.
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Table 3-1 Knockout Dimensions
Conduit Size Trade Sue
Metric Designator
Minimum
Nominal
Ma Maximum ximum
112
16
0.859
0.875
0.906
314
21
1 O94
1.109
1.141
1 1-114
27 35
1.359 1.71 9
1.375 1.734
1.406 1.766
1-112
41
1.958
1.984
2.106
2
53
2.433
2.469
2.500
2-11 2-1 12
63
2.938
2.969
3.000
3
78
3.563
3.594
3.625
33-1 12
91
4.063
4.125
4.156
4
103
4.563
4.641
4.672
129
5.625
5.71 9
5.750
155
6.700
6.813
6.W
5 6
3.1 1
Knockout Diameter,Inches
I
EXTERNAL OPERATING MECH MECHANISMS ANISMS
External operating mechanis mechanisms, ms, when mounted on or through the enclosure, enclosure, shall pass the applicable applicab le test for the t he enclosure en closure Type unless otherwise specified. specified. External operating mechanisms on a Type 3s enclosu enclosure re shall support the additiona a dditionall w weight eight of ice and shal l withstand the removal shall removal of ice by a hand tool. See 5.6. 5.6.2. 2. 3.12
ACCESS TO INTERIOR
Type Ty pe 3, 3R, 3S, 5, 12, and 12K enclosures shall require the use of a tool to gain access to the equipment cavity or shall have provisions for locking. 3.1 3
CLOSING HARDWARE
closing ng hardware for Type 5, 12, 12K enclosures shall be captive. All closi 3.14
GASKETS
A gas gasket ket of an elastomeric or thermopl thermoplastic astic material used to comply comply with the requirements requirements for a Type 2,
3, R, 3S, 4,4X, 5,6,6P, 12,12K, or 13 enclosure, enclosure, shall be subjected to the th e tensile strength and elongation elo ngation tests tes ts in 5.14.1 5.14.1..
If gaskets are provided or Type Type 12, 12K, and 13 enclosuresthey they shall be oil o il resistant and and shall sha ll comply with the Oil ImmersionTest ImmersionTest in 5.14.3. 5.14.3. b e secured with with adhesive or by mechanical mean means. s. The gasket gasket and an d its i ts securing means mea ns A gasket shall be shall not be damaged when the joint is opened. opened.
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3.15
S T D - N E M A 2 5 0- E N G L
3997
b470247 051b49b 5 2 b
OBSERVATIONWINDOWS
A mate material rial covering an observation obser vation opening opening and forming a part of of the enclosure shall be relia r eliably bly
secured in such a manner manner that it i t cannot be readily displac displaced ed in service, shall provide mechanical protectio prot ection n of the enclosed enclose d parts, and shall meet the requirements for the enclosure enclo sure Type Glass used use d for an opening not more mor e than 102 mm mm (not more than 4 inches) in any dimension shall not be less than 1.40 mm (not less than 0.055 inch) thick. Glass used for an opening having no dimension dimensi on greater than 305 mm (greater than 12 inches) shall be not less than 2.92 mm (not less le ss than 0.1 0.1 15 inch) thick. Glass used to cover a larger opening shall have the necessary mechanical strength and shall sha ll otherwise be acceptable for the th e purpose. purpose.
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Section 4 MARKING
4.1
TYPE DESIGNATIONS
Enclosures shall be designated by the Type number to indicate indica te the environmental conditions for which they are suitable. See Section 2 and Table 2-1 and Table 2-2. Enclosures which which meet the requirements requirements for more than one Type Typ e enclosure may be b e designated by a combination of Type numbers, numbers, the lower number being given first. 4.2
SUPPLEMENTAL SUPP LEMENTAL MARKINGS
Enclosures may may be additionally marked with with the followin following g supplemental markings. These are relative terms for reference purposes only and do not imply enclosure capabilities. Raintight
-
Type 3, 3S, 4 , 4 X , 6, or 6P enclosure may be marked Raintight .
Rainproof - A Type 3R enclosure may be marked Rainproof Ra inproof . Watertight
- A Type 4 , 4 X , 6, or 6P enclosure may be marked
Corros ion Resistant Resistant Driptight
4.3
- A Type 4X or 6P enclosure may be marked
2,5, 12,12K 12K,, - A Type 2,5,12,
Dusttight
watertig wate rtight ht . Corrosion Resistant Resistant .
or 13 enclosure enclosure may be marked Driptight Driptight .
- A Type 3,3S, 5,12,12K,
or 13 enclosur enclosure e may be marked Dusttight Dusttight .
LOCATION OF MARKINGS
Type designation and and supplemental markings may may be placed place d at any point p oint on the inside or outside surface of of the enclosure or door where where they will be readily visible after a fter installation. Other required markings may be provided in instruc instructions tions providedwith the enclosure
4.4
ENCLOSURE ORIENTATION
If the acceptability o off a Type 2 or 3R enclosure is dependent upon a particular mounting orientation, the enclosure shall be marked to indicate the required orient orientation ation unless u nless the mounting is obvious. If a Type 2 or 3R enclosure has knockouts for conduit in the sides or back of of the th e enclosure in which
the equipment to be installed is not known, it shall be marked to indicate indica te the area in which live parts are to be installed.
4.5
CONDUIT HUBS HUBS and CLOSURE PLATES
If a Type 3, R or 3s 3 s enclosure has provisions for one or more field-installed separable conduit hubs or closure plates, the enclosure shall be marked with the name or trademark of the manufacturer of of the hubs or plates, the catalog number, number, or conduit sizes sizes of fittings fitti ngs that tha t have ha ve been found acceptable for use with the enclosure. plate s are provided with th the e enclosure the If the field-installed separable conduit hubs or closure plates marking may be omitted. enclosure e has no provisions provisions for field installation of of conduit hubs, the enclosure enclosure If a Type 3, 3 R or 3s enclosur
shall be marked to indicate that raintight hubs that comply with the th e requiremen requirements ts of the th e UL Standard for Fittings Fitting s for Conduit C onduit and Outlet Boxes, UL 514 8 are to be used.
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A Type 4 , 4 X , 6 or 6P enclosu enclosure re shall sha ll b be e marked to ind indicate icate that watert watertight ight fittings are to be use used. d.
A Type 2 , 5 , 1 2 , 1 2 K , or 13 enclosur enclosure e shall be marked to indicate the type of fittings to be used.
4.6
EQUIPMENT OPENINGS
Enclosures provided wit Enclosures with h equipment openings intended to b be e closed at installation ins tallation b by y field installed equipmentt shall be marked to indi equipmen indicate cate that tthe he fie field ld inst installed alled equipment s shall hall be suitable for the same environmental conditions and shall be iinstalled nstalled in accorda accordance nce with the installation instructions provide provided. d.
4.7
DRAINAGE OPENINGS
Types 2 and 3R enclosures that also comply with other e enclosure nclosure shall be provided wit with h instructions indicating that the drainage h hole ole plugs shal shalll be b e removed for Type 2 or 3 R applications and shall be in place for other applications.
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Section 5 DESIGN TESTS
-
5.1
GENERAL
Each enclosure enclosure Type Type shall be evaluated to the specific design tests as outlined in Table 5-1 to demonstrate conformance with this standard. To assure realistic realisti c testing, testing, the enclosure and its enclosed equipment shall be mounted as intended for use in service.
Table 5-1 Applicable Design Tests Enclosure
Applic able Tests
Clause
1
Rod Entry
5.2
2
Rod Entry Drip Indoor Corrosion Corrosion Protection Gasket
5.2 5.3
Outdoor Dust External Icing Outdoorr Corrosion Protection Outdoo Prote ction Gasket
5.5.1 5.6 5.9 5.14
Rod Entry
5.2 5.4 5.6 5.9 5.14
Type
3
.3R
3s
4
Indoor Corrosion Protection
5.8
5.8
5.14
Rain External Icing Outdoor Outdo or Corrosion Protection Gasket
External Icing Outdo Outdoor or Corrosion Protection Protectio n Gasket
5.5.1 5.6 5.9 5.14
External Icing Hosedown Outdoor Corrosion Corrosion Protection Gasket
5.6 5.7 5.9 5.14
Outdoor Dust
Continued
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NEMA 250-1997 Page 18
S T D N E M A 250-ENGL
1997
b470247 7 051b500 88 7 m b47024
Table 5-1 (Continued)
Enclosure TYP
App licabl e Tests Tests
Clause
4x
External Icing Hosedown Outdoor Corrosion Protection 4 X Corrosion Protection
5.6 5.7 5.9 5.10
Gasket
5.14
5
Settling Dust Indoorr Corrosion Protection Indoo Gasket
5.5.2.2 5.8 5.1 4
6
External icing Hosedown Outdoor Corrosion Protection Submersion Gasket
5.6 5.7 5.9 5.11 5.1 4
6P
Extemal icing Hosedown Outdoor Corrosion Protection
5.6 5.7 5.9
4 X Corrosion Protection Air Pressure Gasket
5.1 O 5.12 5.14
12,12K
Circulating Dust Indoor Corrosion Protection Gasket
5.5.2.1 5.8 5.14
13
indoor Corrosion Protection Oil Exclusion Exclusion Gasket
5.8 5.13 5.14
ROD ENTRY TEST
5.2
This test is i s intended to simulate incide in cidenta ntall contact with enclosed equipment. equipment. 5.2.1
Non-ventilated Enclosur es Te Test st Method Method
For Nonventilated Enclosures with live parts pa rts located less than 102 mm (less than 4 inches) from the opening this test shall be made by attempting attem pting to insert a rod having a diameter of 3.2 mm (a diameter of 118 inch). For Nonventilated Enclosures with live parts p arts located 102 mm or more 4 inches or more) from the opening this test shall be made by attemp attempting ting to insert a rod having a diameter of 12.7 mm a diameter of 112 inch).
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Page 19
5.2.2
Ventilated Enclosures Test Method
For Ventilated Enclosures with live parts located loc ated less than 102 mm (less than 4 inches) from the opening openi ng this test shall sha ll be made by attempting to insert inser t a rod ro d having a diameter of of 12.7 mm (a diameter of
112 inch).
For Ventilated Ventilated Enclosures with live parts located locat ed 102 mm or or more mor e (4 inches or more) from the opening this test shall be b e made by attempting to insert a rod having hav ing a diameter of of 19 mm (a diameter of 314 inch). 5.2.3
Evaluation
The enclosure shall be considered to have met the requirements f the rod cannot enter the enclosure.
DRIP TEST
5.3
This test is intended to simulate dripping drippi ng and light ligh t splashing of of liquids. 5.3.1
Method A
The enclosure shall be mount mounted ed beneath a drip dr ip test apparatus which extends beyond beyond all exposed exposed sides of the enclosure. enclosure. The drip test appara a pparatusah tusahall all be equipped equipped with uniformly distributed drip drip sources. sources. There shall be one drip source for each 129 cm (20 in2)of test surface area and each drip source source shall have a drip rate of at least 20 20 drops of of water per p er minute. The enclosure shall be subjected to continuously dripping water for 30 minutes. Conduit shall be connected as intended. 5.3.2
Method B
The enclosure with conduit connected shall be mounted as inte intended nded and the top exposed to a water spray falling for 1 hour at the rate of 25 1 m m h at any angle angle up to 15 from the vertical.
*
5.3.3
Evaluation
A Type 2 enclosure shall shall be considered to have met the requirements f at the conclusion of the test there is no significant significan t accumulation of water within withi n the enclosure and no n o water has entered the enclosure at a level higher than the lowest live part. constructed d that tha t Exception: Water shall be permitted to enter above live parts if he equipment is so constructe no water is visible on the live parts, insulating material, or mechanism parts and no water has entered any space within within the enclosure in which wiring may be present under any proper installation install ation conditions. conditions.
RAIN TEST
5.4
This test is intended to simulate falling rain.
A device that meets the requirements requiremen ts of this test t est also meets the requirements requireme nts of the Drip Dr ip Test (5.3). 5.4.1
Method
A complete enclosure with conduit connected shall sh all be b e mounted as in actual service except that the
conduit shall be connected without using pipe thread sealing seal ing compound compound.. Rigid conduit shall sha ll be threaded into the opening opening in the enclosure and tightened with the torque as specified in Table 5-2. 5-2. The test test apparatus shall consist of of a att least three thr ee spray heads mounted in a water water supply pi pipe pe rack as shown in Figure 5-1. Spr Spray ay heads shall be constructed constructe d in accordance with the details shown in Figure 5-2. The enclosure is to be positioned in the focal area of the spray heads so that the greatest quantity quantity of water is likely to enter the enclosure. water enclosure. The water water pressure is to be maintained at 34.5 kPa (5 psi) at each spray head and a continuous water water spray shall be applied app lied for one hour.
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5.49
Evaluation
A Type 3R enclosure enclosure shall be considered to have met the requirements f at the conclusion of of the test there is no significant accumulation of water within the enclosure and no water has entered the enclosure at a level higher than the lowest live part.
Exception: Water shall be permitted to enter above live li ve parts if the equipment is so constructedthat no water water is visible on the live parts, parts, insulating material, or mechanism parts and no water has entered entere d any space within the enclosure in which wiring may be present under any proper installation conditions.
Table 5-2 Tighteni ng Torque Tightening
I
Torque
Conduit Size
Newton-Meters
Pound Pound-Inches -Inches
Trade Size
Metric Designator Designator
90.4 113
800
3/4 nd smaller
1 O00
1 , 1-1/4, and 1-1/2
180.8
1600
2 and larger
21 and smaller 27,35, nd 41 53 and larger
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STDmNEMA 250-ENGL
1997
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b 4 7 0 2 4 7 05Lb503 5 9 b
m NEMA 250-1 250-1997 997 Page 21
SEE DE DETAI TAIL L 'AI7
l
/
WATER PRES WATER P RESSUR SURE E G GAGE AGE FOR EACH SPRAY HEAD
p I E Z O M E T E R ASSEMBLY DETAIL A
EACH SPRAY HE
item
mm
inch
A
B
71 1400
28 55
C
55
2-114
D
230
9
E
75
3
This material s repm duc ed, with pennission, from U nd em ite rs Laboratories Inc. St Standard andard for for Safety for Enclosures for for Electicai Equipment, UL 50 Copyright 1995 by Underwriters La Laboratories boratories Inc.), copies of which may be purchased from Underwriters Labo ratories lnc ., Publications Publications Stock, 333 Pfingsten Road, Northbro ok, Illinois Illinois 6ûû62-2û96.
Figure 5-1 Rain-test spray-head piping
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S T D - N E M A 250-ENGL
3997
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6470247 0 5 3 b 5 0 4 422
Laboratories inc. Standard for Safety for Enclosures for Electrical This material is reproduc ed, with petmission, from Underwriters Laboratories Equipment, UL 50 Copyright 1995 by Underwritem Laboratories lnc .), copie copiess of whi h mav be ourchased from Underwriters Labor atories nc., Publications Publications Stock, 333 in gs ten Road, Norlhbroo k, IIliinois liinois 60062-2096: 60062-2096: '
are available
~
rom Underwriters Laboratories
b ANWASME ~ 9 4 . 1 1r~i i i ize
Optional To serve as wenc h gdp. ~~
Figure 5 2 Rain-test spray head
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STDmNEMA 250-ENGL 1 9 9 7
5.5
DUST EST
5.5.1
Outdoor Dust Test
=
This test is intended to simulate windblown windblown dust. dust.
05 3 b î b 4 7 0 2 4 7 0 5511 iibb 5 05
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NEMA 250-1997 Page 23
A device that meets the requirements requirem ents of this test also meets the requirements of the Circulating Circulat ing Dust
Test (5.5.2 (5.5.2.1) .1),, th the e Settling Settling Dust Test Tes t (5 (5.5 .5.2 .2.2 .2), ), the Rod Entry Test 5.2),he Drip Dr ip Test Test (5.3), (5.3), and the Rain Test (5.4). 5.5.1.1
Dust Blast Method
en closure shallabe bsuction-type e subjected a blast ofgun compressed air mixedwith withadry general-purpose general-purpo PortlThe Portland andenclosure cement, cement , using suction -typeto sand blast which is equipped 4. 4.7 7Type mm 1 diameter (3/16 (3/16 se inch diameter) air jet and a 9.5 mm diameter (3/8 inch diameter) nozzle. The air shall s hall be dry and at a pressure of 620 to 690 kPa (90 to 100 psi). psi). The cement shall be applied at at a rate of 2. 2.27 kg hi nu te 5 pounddmin pounddmin). ). The nozzle shall be held 305 to 380 38 0 mm (12 to 15 1 5 nches) away from the enclosure, and the blast bla st of air and cement shall be directed at all points p oints of poten p otential tial dust entry, such as seams, seams, joints, external operating mecha mechanisms nisms,, and so forth. The total volume of concrete co ncrete sprayed sprayed shall be at least 5.9 kg per linear lin ear meter of test length (4 pounds per linear foot of test te st length). length) . The test length len gth is equal to the sum of of the height, width, width, and depth of the test specimen.
A conduit shall sh all be permitted to to be installed to equalize the internal an and d extemal pressures. pressures. 5.5.1.2
Evaluation
The enclosure enclo sure shall shal l be considered to have met the requirements if at the conclusion of of the test no dust has entered the enclosure. 5.5.1.3
Hose Method
This test te st is an alternate to the Dust Blast Method described in 5.5.1.1, The enclosure and its external mechanisms shall be subjected to a stream of water from a hose which has a 25 mm inside diameter (1 inch i nch inside diameter) nozzle that delivers at least 170 Umin Umi n (45 gaVmin). gaVmin). The water shall s hall be directed dir ected at all al l points of of potential dust entry such as seams, seams, joints, joints, external ext ernal operating mechanisms, and such from a distance of 3.0 to 3.5 m (10 to 12 feet). The nozzle shall be moved along each test point one time at a uniform nominal rate of 6 mmlsec (Y* inlsec).
A conduit shall be permitted permitte d to be installed installe d o equalize equalize internal and and external pressures pressures but but shall not serve as a drain. 5.5.1.4
Evaluation
The enclosure shall be considered to have met the requiremen requirements ts if at the conclusion of the test no water has entered the enclosure. water enclosure.
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5.5. 5.5.2 2
Indo Indoor or Dust T e s t s
5. 5.5. 5.2. 2.1 1
Circulating Circu lating Dust Test
This test is intended inte nded to simulate an indoor industrial environment of circulating circulatin g dust, lint, l int, fibers, and flyings.
A device that meets the requirements of this test also meets the requirements requireme nts of the th e Settlin Se ttling g Dust
Test (5 (5.5 .5.2 .2.2 .2), ), the Rod Rod Entry Test (5.2), (5.2), and the Drip Test (5.3). 5.5.2.1 5.5 .2.1.1 .1
Dust Method Meth od
The enclosure enclosure shall be placed placed in its intended mounting mounting position position in an airtight chamber having an internal volume not less th than an 0.169 0.169 m3 (6 fi3. The volume volume of of the chamber shall be not less than 150 percent of the volume of the th e enclosure under test (L x W x H). The test chamber shall be b e maintained main tained at at ambient room ro om temperature and 20-50 percent relative humidity. At least le ast 1.5 1.5 kg of dry Type 1 general-purpose Portland cement per cubic meter of te test st chamber cha mber (at least 1.5 ounces per cubic foot) shall be circulated by means of a blower blowe r suction unit uni t for five fiv e minutes min utes so as to completely envelop the enclosure under test. The air velocity at the outlet of of the th e blower blowe r is to be maintained at approximately 305 &min (1O00 ft/min). 5.5.2.1.2
Evaluation
- Dust Method Method
The enclosure shall sha ll be considered to have met met the requirements if at the conclusion of the test no dust has entered entere d the enclosure. 5.5.2 5.5 .2.1. .1.3 3
Atom At omized-Water ized-Water Method Metho d (Meth (Method od A)
This test is an alternate to the Dust Method describe desc ribed d iin n 5. 5.5. 5.2. 2.1. 1.1. 1. The enclosure shall be subjected to a spray of atomized water using a nozzle which produc pr oduces es a round pattern 75 o 100 nm in diameter when measured 300 mm from the nozzle (3 o 4 inches in diameter when measured 12 inches inch es from the nozzle). The air pressure shall be 200 kPa (30 si) and the nozzle shall deliver del iver water at a rate of 11.4 L 3 gallons) per hour. The nozzle shall be held from 300 to 380 mm (12 to 15 inches) from the enclosure and the th e spray of water shall shal l be directed at all points of of potential po tential dust entry such as seams, seams, joints, external exter nal operati ope rating ng mechanisms, and such. The nozzle shall be moved along each test point poi nt one time at a uniform nominal rate of 6 mrrúsec Yi idsec).
A conduit shall shall be permitted to be installed o equal equalize ize the intemal and external pressures pressure s but shall not
serve as a drain.
A seam is the junction junc tion of, or the joint between, between, two two pieces. When two covers or doors
re
adjacent,
their common edges shall be b e considered a single sea seam. m. 5.5.2.1.4
Evaluation
- Ato Atomized mized Wa Water ter Method (Metho (Method d A)
The enclosure shall sha ll be considered to have met the requirements if at the conclusion of the test no water has entered the enclosure. 5.5. 5.5.2. 2.2 2
Settlin Settl ing g Dus Dustt Test
This test is intended to simulate an indoor industrial environmen environmentt of settling settl ing airborne dust, lint, fibers, and fiyings.
A device that meets the requirements of this test also meets the requirements of of the th e Rod Ro d Entiy Ent iy Test
(5.2) and the Drip D rip Test 5.3).
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5. 5.5.2 5.2.2. .2.1 1
Dus Dustt Method Metho d
At least 0.85 kg of dry Type 1 General Purpose Portland cement per cubic meter of test chamber (at least 0.85 ounces per cubic foot) foot) is i s to be circulated by means of of a blower blow er suction sucti on unit so as to completely envelop the enclosure under test. The air velocity at the outlet of the blower blow er is to be 304.8 d m i n (1000 Wmin). The blower shall be cycled 15 seconds on and 30 seconds off for seven complete cycles.
5.5.2.2.2
Evaluation
- Dust Method
The enclosure shall be considered to have met the requirements if at the conclusion of the test no dust has entered the th e enclosure. 5.5. 5.5.2. 2.2. 2.3 3 Ato Atomized-Water mized-Water Method (Method B) This test is an alternate to the dust method method described in 5.5.2.2.1.
The enclosure shall be subjected to a spray of of atomized water using usin g a nozzle that produces produce s a round pattern 75 to 100 mm in diameter when measured 300 mm from the nozzle n ozzle (3 o 4 inches in diameter when measured 12 inches from the nozzle). nozzle). The air pressure shall be 170 kPa (25 psi) and the nozzle shall deliver de liver water at a flowrate of 1 1.4 ühour (3 gaihour). The nozzle no zzle shall be held from 460 to 530 mm (18 to 21 inches) away from the enclosure and the spray of of water shall sh all be directed at ali points of of potential potentia l settling airbor ai rborne ne dust entry such as seams, joints, joints, external operating operati ng mechanism mechanisms, s, and such. such. The nozzle noz zle shall shal l be moved move d along each test point poin t one time at a uniform nominal nomin al rate of 11 mmls (7/16 irúsec). permitted to be installed to equalize the internal and external pressure, pressure, but bu t shall not A conduit shall be permitted
serve as a drain.
A seam is the junction of, or the joint between, two pieces. When two covers or doors are adjacent,
their common edges shall be considered conside red a single sin gle seam. 5.5 5.5.2.2 .2.2.4 .4
Evaluatio Evalu atio n Atom Atomized ized Water Test (Method B
The enclosure shall be considered to have met the requirements if at the th e conclusion of of the test no water has entered en tered the enclosure.
5.6
EXTERNAL ICING TEST
This test te st is intended intend ed to simulate freezing rain, sleet, and snow. snow.
A Type 3,3R, 4,4X, 6, and 6P 6P enclosure which has no external exter nal cavities caviti es to trap water when mounted
in the normal position shall shall be considered to be acceptable and need not be b e tested. tested.
5.6.1
Test Test Method
The enclosure shall be mount mounted ed in a room which which can be cooled to -7°C (20°F). A metal test bar ba r which is 25.4 mm in diameter by 600 mm long (1 inch in i n diameter diameter and 2 eet long) shall be mounted in a
horizontal position position in a location location where it will receive receive the same general water spray as the enclosure under under test. Provision shall be made made for spraying the entire enclosure from above abo ve with water at an angle of approximately 45 degrees from the vertical. The water shall be between 0°C and 3°C (32°F nd 37°F).
Spraying Sprayin g facilities facil ities which provide between 40 and 80 L per hour per pe r square meter meter (1 and 2 gallons per hour per square foot) of area to be sprayed have been found effecti eff ective. ve. The room temperature temperature shall shall be b e lowered to 35°F (2°C). The spray of water shall be started and continued for at least 1 hour, maintaining the room temperature between betwe en 1 OC and 3°C (33°F and 37°F).
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At the end of of this thi s time, the room temperature shall sha ll be lowered low ered to between -7°C and -3°C (20°F and 27°F) while continuing the water spray. spray. (T (The he rate of change chan ge in i n the room temperature is not critical and shall be whatever is obtainable with the cooling means employed employed.) .) The water spray shall shall be controlled so as to cause ice to build bui ld up on the bar at a rate of approximately appr oximately 6.35 mm/hour 1/4 inhou inhour) r) and shall be continued until 20 mm (314 inch) of of ice has formed on the top surface of the bar. bar. The spray shall then be
discontinued discontin ued but the room tempera temperature ture shall shal l be maintained between -7°C and -3°C 20°Fand 27°F) for 3 hours to assure that all a ll parts of the enclosure and ice coatings have been equalized to a constant temperature. 5.6.2
Evaluation
A Type 3s enclosure and and its extemal mechanisms shall be considered to have met the requirements of this test if while ice laden, they can be manually manu ally operated by one pers person on without without any damage to the enclosure, the enclosed en closed equipment, or mechanism. When an auxiliary mechanism is provided to break the ice, it shall be included and utilized utilize d in the test. test. A separate test is required requir ed for each maintained maintain ed position of each external externa l operator. If necessary, it shall be possible possi ble to to gain access to the enclosure enclosure interior inter ior using an appropriate hand tool without causing functional damage to the enclosure.
A Type 3,3R, , 4X, 6, and 6P enclosure shall be considered to have met the requirements f at the conclusio conc lusion n of of the th e test the enclosure is found to be undamaged after the ice has melted. HOSEDOWNTEST
5.7
This test is intended intend ed to simulate simula te a hosedown condition.
A device that meets the requirements of of this th is test also meets the requirements requireme nts of the Rod Entry Test 5.2), rip Test 5.3), ain Test (5.4), and Dust Tests (5.5). 5.7.1
Test Method
Th The e enclosure and its external mechanisms shall be subjected subjecte d to a stream of water from a hose which has a 25 mm inside diameter (1 inch inside diameter) nozzle that delivers delive rs at least 240 L per min (65 gallons per minute). The nozzle shall be held he ld from 3.0 to 3.5 m (10 to 12 feet) away from the enclosure and the spray of of water shall be directed at all points of potentia pot entiall water entry en try such as seams, joints, external operating operatin g mechani mec hanisms sms,, and such. such. The nozzle nozzl e shall be moved along each test point po int one time at a uniform nominal rate of 6 mmlsec (W idsec).
A condu conduit it shall be permitted to be installed install ed to equalize internal inter nal and external pressures but shall not serve as a drain. Evaluation 5.7.2 The enclosure enclosure shall be considered to have met the requirements if at the conclusion of the test no water has entered the enclosure. 5.8
indoor Corros ion Protect ion (Rust (Rust -Resis -Resistance tance Test (24(24-Hour Hour Salt Spray Test)) Test))
Unless the enclosures comply with 3.5.1, the enclosures, or representative representative parts of the enclosures enclosures,, shall be subjected to the test described below or in i n Salt Spray (Fog) Testing, ASTM B117-1985. Test Equipment
5.8.1
The test apparatus shall consist of a fog chamber, a salt-s s alt-solut olution ion reservoir, a supply of compressed air, atomizing nozzles, support for the enclosure, provision provi sion for heating heat ing th the e chamber, chamber, and means of control. It shall not permit drops of solution which accumulate accumu late on the ceiling ceil ing or cover of the chamber to fall on the enclosure being tested, tested, s shall hall not permit drops of soluti s olution on which fall from fro m the enclosure to be returned to
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250-1997 997 NEMA 250-1 Page 27
the solution reservoir reservoir for respraying, respraying, and shall be constructed of of materials which will not affect the corrosiveness corrosive ness of the th e fog. 5.8.2
Salt Solutio n
The salt solution shall be prepared by dissolving 5 parts by weight of salt in 95 parts by weight weigh t of
either distilled water either water or water containing not more than 200 parts per million mi llion of total tot al solids. solids. The salt shall be sodium chloride which is i s substantially free of nickel n ickel and copper and which contains, when dry, not more than 0.1 percent of of sodium iodide and not more more than 0.3 percent perc ent of total tota l impurities. impuri ties. 5.8.3
Air Ai r Sup uppl ply y
The compressed air supply to the nozzle(s) for atomizing the sait solution solu tion shall sha ll be free of oil oi l and dirt and shall be maintain maintained ed between between 69 69 and 172 17 2 kPa (between 10 and 25 psi). 5.8.4
Temperature
The temperature of the salt spray chamber shall be maintaine maintained d between 33°C and 36°C (between 92 92°F °F and 97°F) 97°F).. The noul no ule( e(s) s) shall be directed or baffled so that none of the t he spray can impinge impin ge directly directly on the enclosure enclo sure being tested. 5.8.5
Test Procedure
The chamber shall be closed and and the spray operated cont continuously inuously except for the short daily d aily interruption interrup tion necessary to inspect, rearrange, or or remove the test specimens, to check and repleni rep lenish sh the solution in the reservoir, and to make necessaiy recordings. The test shall be run continuously continuously for 24 hours. hours. At the end of of the test, test , the specimens shall shal l be removed from the th e chamber and washed in clean running water which is not warmer than 38°C 100°F) to remove remov e salt deposits from their surface, surface, and then dried immediately. Corrosion products, products, o other ther than rust, shall be permitted pe rmitted to be removed by by light brushing f required, to observe the condition con dition of of tthe he underlying stratum. 5.8.6
Evaluation
The enclosure shall be considered o have met met the requirements of this tes testt if there is no n o rust except except at those points where protection is impractical, such as machined and mating surfaces of cast ca st enclosures and sliding slidin g surfaces of hinges, shafts, shafts, and so forth. OUTDOOR CORROSION PROTECTION
5.9
Finishes other than as described in 3. 3.5. 5.2. 2.1 1 to 3.5. 3.5.2. 2.5, 5, such as special spec ial metallic meta llic finishes, finishes, or metallic metall ic finish combined comb ined with paint p aint shall be tested as described describe d in 5. 5.9. 9.1 1 and 5.9. 5.9.3. 3. 5.9.1
600 Hour Salt Spray Test
Comparative tests shall sh all be conducted in accordance with 5.8 except the test time shall be 600 hours. The comparison shall be with G90 galvanized sheet steel (without annealing, wiping, or other surface surface treatmen trea tment) t) conforming confor ming wi with th 3.5. 5.2. 2.1. 5.92
Evaluation
An enclosure shall be considered considered to have met the requirements of this thi s test if upon completion it does not show pitting, cracking, or other deterioration deterioration more more severe than that resulting resul ting from a similar test on G90 galvanized steel. 5.9.3
1200 Hour Moist Carbon Carbon Dioxide Sulfur Dioxide Air Test
Tested and evaluated in accordance with UL 1332.
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5.10
TYPE 4X CORROSION PROTECTION
A Type 4X and 6P enclosure shall be tested with comparison tests i n accordance accordance with 5.8 except the test time shall be 200 hours. The comparison shall be with Amencan Amencan Iron and Steel Institute Type Type 304 stainless steel.
5.10.1
Evaluation
An enclosure shall shal l be considered to have met the requirements requireme nts of this test if upon completion it does not show show pitting, cracking, cracking, or other deterioration deteri oration more severe sever e than that resulting from a similar test on passivated American Iron Iro n and and Steel Ste el Institut Ins titute e Type 304 stainless steel. 5.11
SUBMERSION TEST
This test is i s intended to simulate temporary temporary submersion at a limited depth. depth.
A device that meets the requirements of this thi s test also al so meets the requirements requireme nts of the Rod Entry Test
(5.2).
5.11.1
Test Method
The complete complete enclosure enclosure shall be mounted mounted in a tank tan k with the conduit connected using pipe-thread pipe-thread sealing compo compound und.. The conduit shall shall be tightened with the to t o qu e values specified in Table 5-2. The tank shall be filled with water so that the highest highe st point of the th e enclosure is 1.8 1.8 m below the surface (6 feet below the surface) of the water. After 30 minutes, the enclosures shall be removed from the tank, the excess water water removed from the surface of the th e enclosure, enclos ure, and the t he enclosure enclo sure opened. opened. The enclosure need not be submersed to a depth d epth of 1. 1.8 8 m (dept (depth h of 6 feet) if an equivalent pressure pressure differenti al between differential between the interi i nterior or and the exterior of the t he enclosure enclosu re is i s maintained maintain ed for the required period of of time.. This differential shall be permitted to be achieved either by reducing the air time ai r pressure inside the enclosure or pressurizing pressurizin g the water surrounding surr ounding the enclosure. 5.11.2 5.1 1.2
Evaluation
The enclosure shall be considere considered d to have ha ve met the requirements requireme nts if at the conclusion of the test no water has entered the enclosure. 5.12
PRESSURE TEST
This test is intended to simulate prolonged submersion at a limited limite d depth depth.. A device that meets the requirements of this test also meets the requirements req uirements of of the Rod Entry Test (5.2) and the Submersion Submersion Test (5. (5.1 1 1). 5.12.1
Aiternate Tests
The internal Pressurization Pressuriza tion Test in 5.12 5.12.1 .1.1 .1 and the External Pressurization Pressuriza tion Test in i n 5.12.1.3 are alternate test methods and either may be conducted. 5.12 5.12.1 .1.1 .1 Internal Inter nal Pressur Press urizati ization on Test
The complete enclosure with conduit, pressure gage, and check valve shall sha ll be pressure tested. tested. The internal air pressure pressure of the enclosure enclosure shall be b e raised to 40 kPa (6 psig) and the check valve closed. closed. Aiter 24 hours the pressure shall be checked. The conduit shall be connected using pipe-thread sealing compound and shall be tightened with the toqu to que e specif specified ied in Tabl Table e 5-2.
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5.12.1.2
Evaluation
- nternal Pressurization
Th The e enclosure shall sha ll be considered to have met the requirements f at the conclusion of of the te test st the internall pressure is a minimum of 26 kPa (4 psig) and there is no permanent deformation of the interna enclosure. 5.12.1.3
External Pressurization Test Test
Submerge the complete enclosure, connected as as intended intend ed for use, use, i n water so that the highest point of the enclosure is 1.8m below the surface 6 eet below the surface) fo forr a period of 24 hours. The enclosure enclos ure need nee d not be submerged to a depth of 1.8 m (depth (dep th of 6 eet) if th the e equivalent pressure pressure differen diff erential tial between the interio i nteriorr a and nd exterior of of the th e enclosure is maintained maintained for the requ required ired period of of time. This differe differential ntial shall be permitted to be achieved by pressurizing he water around the enclosure to simulate a depth of 1.8 m (depth (de pth of 6 eet). 5.12.1.4 Evaluation The Th e enclosure shall sh all be considered to to have met the requirements requirements f at the conclusion conclusion of the test no water has entered the enclosure. enclosure.
OIL EXCLUSIONTEST
5.13
This test is intended inten ded to simulate spraying water, water, oil and noncorrosive coolant. A device that meets the requirements require ments of this test also meets the requirements requirements of of tthe he Rod Entry Test 5.2),he Rain Test Test 5.4), and the Dust Tests Tests (5.5). The compatibility of the gasket with other sealing materials and liquids to which it is exposed may have to be determined by tests. tests. 5.13.1
Test Te st Meth Me thod od
The enclosure shall be subjected to a stream of test liquid liq uid consisting of water and a wetting agent. The concentration of the wetting agent shall be approximately 0.1 percent by weight or by volume i the wetting wettin g agent is liquid). liqu id). The liquid liq uid shall be supplied through a nozzle nozzle with a 1 O mm diameter opening 318 inch diameter opening) which delivers at at least 7 Umin 2 avrnin). Note: One such wetting wettin g agent is Rohm and Haas' Triton X-100. The stream shall be directed upon the enclosure enclosu re from all al l angles from a distance of 300 o 460 mm (a distan ce of 12 o i nches) for 30 minutes. If the enclosure houses distance houses an an externally operated o perated device, device, the device shall sha ll be operated at a rate of of app approximately roximately 30 operations per per minute for the duration of the test. te st. A conduit shall be permitted to be installed to equalize internal and extemal pressures but shall not serve as a drain. 5.13.2 Evaluation The enclosure shall be considered to have met the requirements requirements f at the conclusion of the test no test liquid has entered the enclosur enclosure. e. 5.14
GASKET TESTS
5.14.1
Aging Test
Gasket material used in a Type 2,3,3R,S, , 4 X , 5,6 5,6,6P ,6P, ,2,12K 2,12K, , r 13 enclosure shall be of such quality that samples subjected to a temperature o off 69-70 69-70°C °C 156-158°F)n circulating air for 168 hours hours have a tensile tens ile streng st rength th of not less les s than 75% and an elongation elonga tion of not less than 60 of values determined dete rmined for unaged samples.
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5.1 4 9
Evaluation
At the conclusion conclusio n of the tests, there shall sha ll be no visible deterioration, deformation, melting, or cracking of the material mate rial and the material shall not harden as determined by normal hand flexing.
5.14.3
Oil immersion test
Gasket material, if used in a Type 12,12K, or 13 enclosure, shall not swell more than 25 percent or 13enclosure,
shrink more than 1 percent as a result of of immersion in ASTM Reference Oil No. 3 see the Standard Standard e s t Method Met hodfor Rubb Rubber er Property Prope rtyEff Eff ecî of Liquids, ASTM D471-79, for oil specifications) specifications) or IRM Immersion Oil 903 (see ASTM ES27-94) for 70 hours at room temperature. temperature.
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APPENDIX A Comparis on Betwee Between n NEMA Enclo sur e Type Numb ers a and nd IEC Enclo sur e Cla Classifi ssifi cation De Designation signation s IEC Publication 529 Class Classifica ification tion of Degrees of of Protection Protection Provided by Enclosures Enclosures provides a system for specifying the enclosures of of electrical equipment equipment on the basis of the degree of of protection provided by the
enclosure. IEC 529 does does not specify degrees of protection prot ection against mechanical damage of of equipment, risk of explosions, or conditions such as moisture (produced (produced for example example by condensation) condensation),, corrosive cor rosive vapors, fungus, or vermin. The NEMA Standard for Enclosures Enclosures for Electrical Electrical Equipment does test for environment env ironmental al conditions such as corrosion, rust, icing, oil, and coolants. For this reason, and because the test and evaluations evaluatio ns for other characteristics char acteristics are are not identical, identical, the IEC Enclosure Enclosure Classification Classification Designations Designations cannot be exactly exa ctly equated with the enclosure Type Type numbers numbers in this Standard. Standard. The IEC designation consists of of the th e letters IP followed by by two num numeral erals. s. The first characteristic characteristic numeral indicates the degree of protection provided by the enclosure with respect to persons and solid foreign objects entering the enclosure. The second characteristic numeral indicatesthe degree of protection provided provided by the enclosur encl osure e with respect to the harmful harm ful ingress of water. water. Table A-1 provides an equivalent conversion from the enclosure Ty Type pe numbers numbers in this Standard to the IEC Enclosure Classification Classificatio n Designations Designations.. The enclosure t yp numbers meet or exceed the test requirements for the associated IEC Classification; Classification; for this reason Table A-1 cannot be used to to convert from IEC Classifications Classificatio ns to enclosure Type numbers. numbers.
Table A-1 Conversion f Enclos ure Type numb ers to IEC Classif Classif icati on Designations Designations (Cannot (Ca nnot be usedoto convert IEC Classification ClassificationDe Designatio signations ns to NEMA NEMA Type numbers) Enclosure Type Number
1
I
Classification Deslgnaîion
I
IP1o
IEC Endosure
2
IP11
3
IPS
3R
IP14
3s
IP54
4 and 4X
IP56
5
P52
6 AND 6P
IP67
12 AND AND 12K
IP52
13
IP54
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Supplement A DESCRIPTIONS DESCRI PTIONS,, APP APPLICATIO LICATIO IS, FEATURES, FEATURES, AND TEST CRITERIA O OF F Ei CLOSURES FOR HAZARDOUS (CLASSIFIED) LOCA LOCATIONS TIONS
SA1.l
GENERAL
Type 7 and 10 enclosu enclosures, res, when properly installed and maintained, maintained, are designed to contain con tain an internal explosion withou withoutt causing an extemal hazard. hazard. Type Type 8 enclosures enclosures are deigned to prevent combustion combustio n through the use of of oil-im oi l-immerse mersed d equipment. equipment. Type 9 enclosures are designed to preven pr eventt th the e ignition igni tion of combustible combustibl e dust. Hazardous Hazar dous locations (other than than in mines) mines) are classified according to the flammability fla mmability or combustibility of the materials which which may be present and also also according to the likelihood l ikelihood hat a flammable or combustible concentration concentration is present (For definitions and classifications see the National Electrical Ele ctrical Code, Code, Article 500, and ANSVNFPA 497M, Cla Classification ssification of Gas es, Vapors and and Dust for Electrical Equipm ent in Hazardous C/assjfied) C/assjfied)Locations. Locations. Descriptionsand tests in this standards publication cover equipment which is suitable for for installation in locations classe classed d as Division 1 or Division 2. In Division 2 locations, other types of protection protectio n and enclosures for nonhazardous ocations oca tions may be installed f the equipment does not constitute a sourc source e of ignition under normal operating operating conditions. conditions. (See the specific sections of Articles 501 through 503 of the National Electrical Elec trical Code.) Code.) Enclosures Enclos ures for for non-hazardous ocations described described in the main part of this standards publication publica tion which which have met the requirements of the dust test described in 5.5, may be used in Class II Grou Group p G, Division 2, and Class III Division 1 and 2 locations. Hazards may he reduced or eliminated and equipment Hazards equipment installed in enclosures suitable ffor or nonhazardous hazard ous locations by adequate positive positive pressure pressure ventilation ventilation from a source of clean clea n air ai r in conjunction with effective safeguards against ventilation failure. See ANSINFPA ANSI NFPA 496, 496 , Purge Purged d and Pressun ied Enclos ures for Electrical Electrical Equip ment, for detailed requirements. SA2.1
SPECIFIC TYPES
Table SA-1 is a guide for comparing c omparing specific applications applicatio ns of enclosures. The specific enclosure Types, their applications, and the environmental conditions they are designed to protect against are as follows: Type 7 - Enclos Enclosures ures constructed constructed for indoor use in hazardous hazardous locations classified as Class I Division 1, Groups A, B, C, or D as defined in i n NFPA 70. 70. Type 8 - Enclos Enclosures ures constructed constructed for either indoor or outdoor use in hazardous hazardous locations classifie cla ssified d as
Class I Division 1, Groups A, B, C, a and nd D as defined in in NFPA 70.
-
Type 9 Enclosures constructed constructe d for for indoor use in hazardous locations location s classifie class ified d as Class II Division 1, Groups E,F, or G as defined de fined in NFPA 70. Type 10 - Enclosures constructed to meet the requirements of the Mine Safety and Health Hea lth Administration, 30 CFR, Part 18.
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Table SA-1 Comparison of Specific Applications of Enclosures for Indoor Hazardous Locations (If (If the installation is outdoors a and/ nd/or or additional protectio n is required by Table Tabl e 2-1 and Tabl Table e 2-2 2-2,, a combination-type enclos enclosure ure is required) Provides a Degree of Protection Against
Enclosure Types 7 a n d
Enclosure Type 9
Atm ospheres Typically Containing See FPA 497M for Com plete Listing)
Acetylene
8, Class Groups ** Class
A
I
X
...
Hydrogen, manufact manufactured ured gas gas Diethy Die thyll ether, ethylene, cyclopropane
...
Gasoline, hexane, butane, Gasoline, butane, naphtha, propane, propane, acetone, toluene, isoprene isoprene
...
Metal dust
II
...
Carbon Carbo n black, coal coal dust, coke dust
II
...
Flour, starch, grain grain dust dust
II
Fibers, flyings
III
Methane with or without coal dust * **
MSHA
...
...
...
B
C
...
...
...
X
... ...
x ...
... ... ... ... ...
... ...
...
1
...
Class Groups D
...
... ...
E
F
... ...
...
G
...
... ...
...
1
...
...
0
... ...
x
...
...
...
... ...
... ... ... ... ...
x
... x
...
...
... ... ...
...
... ...
...
... x x
...
...
... ... x
For Class Ili type ignitable fibers or combustible flyings s ee the National Electrical ElectricalCode, Code, Article 500. Due to the characteristics of the gas, vapor, or dust, a product suitable for one Class or Group may not be suitable for another Class or Group unless marked on the product.
SA3.1 SA3.1.1
ENCLOSURE FEATURES Type 7 Enclosures
Type 7 enclosures shall be capabl capable e of withstanding withstanding the pressures resulting from an intemal explosion of specified gases, gases, and contain such such an explosion sufficient hat an explosive e xplosive gas-air mixture existing in the atmosphere surrounding surround ing the enclosure will not be ignited. Enclosed heat generating ge nerating devices shall not cause external surfaces to reach temperatures temperatures capable capable of igniting explosive gas-air mixtures in the surrounding atmosphere. atmosphere. Enclosures shall meet explosion, hydrostatic, and tempera temperature ture design tests. When completely and properly installed install ed Type 7 enclosures: a. Provide a degree of protection o a hazardous gas environment environme nt fro from m an internal intern al explosion or from operation operatio n of of internal equipment b. Do not develop surface temperatures which exceed prescribed limits for the specific gas corresponding to the atmospheres atmospheresfor which which the enclosure enclosure is intended, when internal equipment is operated at rated rat ed load. c. Withstand a series of internal explosion design tests which determine: determine : 1. The maximum pressure effects effec ts of the gas gas mixture. 2. Propagation Propaga tion effects of the gas mixtures. d. Withstand, without rupture or perman permanent ent distortio distortion, n, an intemal inte mal hydrostatic design test based on the maximum maximum intemal pressure pressure obtained during during explosion tests and on a specified safety factor. e. Are marked with the appropriate Class and Group(s)for which they have h ave been qualified. qualified . SA3.1.2 Type 8 Enclosures
Type 8 enclosures and and enclosed enclosed devices devices are arranged arranged such that all a ll arcing a rcing contacts, connections, and so forth, are immersed in oil. oil. Arcing Arcing is confined confine d under the oil oi l such that it will not ignite an explosive mixture of of the th e specified gases in intemal intema l spaces spaces above the oil o il or in the atmosphere surroun surrounding ding the
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enclosure. Enclosed heat generating devices shall not cause external externa l surfaces to reach temperatures temperature s capable of of igniting ig niting explosive gas-air mixtures in the surround surr ounding ing atmosphere. atmosphere. Enclosures shall meet operation and temperature design tests. Enclosures Enclosure s intended inten ded for outdoor use shall also meet the rain test. When completely and properly installed, Type 8 enclosures: a. Provide, by oi oill immersion, a degree of protection prote ction to a hazardous hazard ous gas environment from operation of internal equipment.
Do not develop develop surface temperatures temperatures which exceed prescribed pr escribed limits for the specific gas corresponding to the atmospheres for which the enclosure is intended, when internal equipment is at rated load. load. c. Withstand a series of of operation design tests with oil levels arbitrarily a rbitrarily reduced and with flammable flammable gas-air mixtures introduced intro duced above the oil. d. When intended for installation installati on outdoors, shall exclude exclu de water under test conditions which are intended to simulate rain. e. Are marked with the appropriate Class and Group@) or which they have been qualified. b.
SA3.2.3
Type 9 Enclosures
Type 9 enclosures shall be capable of preventing the entranc ent rance e of dust. Enclosed heat generating generatin g devices shall not cause external surfaces to reach temperatu tempe ratures res capable of of igniting igni ting or discoloring discolori ng dust on on the enclosure or igniting dust-air mixtures in the surrounding surroun ding atmosphere. Enclosures shall meet dust penetration penetratio n and temperature temperature design tests, and aging of gaskets (if used). When completely completely and properly p roperly installed, instal led, Type 9 enclosures: a. Provide a degree of of protection to a hazardous hazardou s dust environment from operation of of interna in ternall equipment. b. c.
d.
develop surface temperatur temperatures es which exceed exce ed prescribed pre scribed limits for the Group corresponding corresponding Do not develop to the atmospheres for which the enclosure is intended, when internal equipment is operated at rated load. Withstand Withstand a cenes cenes of of operation design tests while exposed to a circulating cir culating dust dust mixture, mixture, to determine that dust does not enter the enclosure and tha thatt operation of devi devices ces does not cause ignition of the surrounding atmosphere. Are marked marked with the appropriate Class and Group(s) for which they have been qualified. qualified .
SA3.1.4
Type 10 Endosures
Nonventilated Type 10 Enclosures are constructed for mine use and to meet the requirements requireme nts of the Mine Safety and Health He alth Administration.
SA4.1
ENCLOSURETEST CRITERIA
SA4.1.1 Type 7 Enclosures Type 7 enclosures shall he tested and evaluated in accordance accordan ce with the applicable portions po rtions of: of: a. ANSINL 698. Industria Industriall Control Equipment for Use n Hazardo Hazardo us Classified) Locations. b. ANSWL 877, Circuit Breaker Breakerss and Circuit Breaker Enc losures for Use in Hazardous Classified) c. d.
Locations.
ANSVUL 886, Outlet Boxes and Fittings for Us e in Hazardous Classified) Lo cations, ANSILJL894. Switch es for for Us e iin n Hazardous Classified ) Locations.
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SA4.1.2
Type 8 Enclosures
Type 8 enclosures shall be tested and evaluated evaluate d in accordance accordan ce with the applicable a pplicable portions portio ns of: of: a. ANSIAJL 698, Industrial Control Equipmen Equipmentt for Use in Hazardous Hazardous C/assified) C/assified )Locations. b Breakers s and Circuit- Breaker Enclosures for Use in Hazardou Hazardous s classifie clas sified) d) ANSVUL 877, Circuit Breaker Locations. c. Rain test described in 5.4.
SA4.1.3 Type 9 Enclosures Type 9 enclosures shall be tested and evaluated in accordance with with tthe he applicable portions of: of: a. b c. d.
ANSIAJL 698, Industrial ialreakers Control Equipment for Use Enclosures in Hazardous Hazardous Classifie d) Location Locations. s. 877, Industr ANSIAJL Circuit Break B ers and an d Circuit Breaker for Classified) Use in Haz Hazardo ardous us Classified) Classified ) Locations. Boxes and Fittings Fittings for Use in Hazardous classi cla ssifie fied) d)Locations. Locations. ANSI/UL 886, Outlet Boxes ANSIAJL 894, Switches for Use in Hazard Hazardous ous Classified) Classifie d) Locations.
SA4.1.4 Type 10 Enclosures
The design test for Type 10 enclosures shall be in accordance with the Mine Safety and Health Administration, 30 CFR Part 18.
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