34-SAMSS-820 - Instrument Control Cabinets - Indoor

Materials System Specification 34-SAMSS-820 Instrument Control Cabinets - Indoor

1 January 2013

Document Responsibility: Instrumentation Standards Committee

Saudi Aramco DeskTop Standards Table of Contents 1

Scope............................................................. 2

2

Conflicts and Deviations................................. 2

3

References..................................................... 3

4

Definitions....................................................... 4

5

General Requirements................................... 4

6

Design............................................................ 5

7

Electrical......................................................... 9

8

Testing and Inspection................................. 22

9

Shipment…………………………………...…. 23

Previous Issue: 6 September 2011 Next Planned Update: 1 January 2017 Revised paragraphs are indicated in the right margin Primary contact: Tarawn, Al Ahmed Roja Mahd on +966-3-8801344 Copyright©Saudi Aramco 2013. All rights reserved.

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Document Responsibility: Instrumentation Standards Committee Issue Date: 1 January 2013 Next Planned Update: 1 January 2017

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34-SAMSS-820 Instrument Control Cabinets - Indoor

Scope This specification defines the requirements for instrument control panels, control cabinets, and marshalling cabinets for location in electrically unclassified airconditioned buildings. Programmable Logic Controller (PLC), auxiliary systems, and Rotating Equipment Protection control cabinets must adhere to this specification. Excluded from this specification are:

2

a)

Vendor standard Fire Detection / Suppression Panels / Cabinets used for building protection.

b)

Vendor standard Security Alarm Panels / Cabinets.

c)

System Cabinets for Distributed Control System (DCS) except as referenced in 23-SAMSS-010.

d)

Consoles and server cabinets for Distributed Control Systems (DCS) except as referenced in 23-SAMSS-010.

e)

Control panels that are provided as part of packaged Units.

f)

ESD System Cabinets except as referenced in 34-SAMSS-623.

g)

RTU System Cabinets except as referenced in 23-SAMSS-030.

Conflicts and Deviations 2.1

Any conflicts between this specification and their applicable Saudi Aramco Materials System Specifications (SAMSS), Engineering Standards (SAESs), Standard Drawings (SASDs), or industry standards, codes and forms shall be resolved in writing by the Company or Buyer Representative through the Manager, Process & Control Systems Department of Saudi Aramco, Dhahran.

2.2

Direct all requests to deviate from this specification in writing to the Company or Buyer Representative, who shall follow internal company procedure SAEP-302 and forward such requests to the Manager, Process & Control Systems Department of Saudi Aramco, Dhahran.

2.3

The designation “Commentary” is used to label a sub-paragraph that contains comments that are explanatory or advisory. These comments are not mandatory, except to the extent that they explain mandatory requirements contained in this SAMSS.

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Document Responsibility: Instrumentation Standards Committee Issue Date: 1 January 2013 Next Planned Update: 1 January 2017

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34-SAMSS-820 Instrument Control Cabinets - Indoor

References Referenced standards and specifications shall be the latest edition, revision or addendum in effect on the date of the Purchase Order, unless stated otherwise. 3.1

Saudi Aramco References Saudi Aramco Engineering Procedure SAEP-302

Instructions for Obtaining a Waiver of a Mandatory Saudi Aramco Engineering Requirement

Saudi Aramco Materials System Specifications 23-SAMSS-010

Distributed Control Systems

34-SAMSS-623

Programmable Controller Based ESD Systems

23-SAMSS-030

Remote Terminal Unit

Saudi Aramco Inspection Requirements 175-343100 3.2

Instrument Control Panels

Industry Codes and Standards National Fire Protection Association NFPA 70 (2011)

National Electrical Code

National Electrical Manufacturers Association NEMA ICS 6

Enclosures for Industrial Controls and Systems

NEMA 250

Enclosures for Electrical Equipment (1000 Volts Maximum)

International Electro-Technical Commission IEC 61000-4-3

Radiated Electromagnetic Field Requirements

International Society for Measurement and Control ISA RP60.6

Nameplates, Labels and Tags for Control Centers

Underwriters Laboratories, Inc. UL 94

UL Standard for Safety Test for Flammability of Plastic Materials for Parts in Devices and Appliances

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Document Responsibility: Instrumentation Standards Committee Issue Date: 1 January 2013 Next Planned Update: 1 January 2017

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34-SAMSS-820 Instrument Control Cabinets - Indoor

Definitions Control Panel: A surface with cut-out(s) used to mount control devices and/or instrument indicators (e.g., totalizers, pushbuttons, pullbuttons, indicating lights, meters, annunciators, etc.). Control Cabinet: An enclosed structure containing electronic equipment and wiring for process control / status devices. (The front surface of a control cabinet may include a control panel.). Cabinets containing DCS field termination assemblies (FTAs) should be treated as control cabinets. Marshalling Cabinet: A cabinet containing mainly terminal strips and wire terminations. The field wiring is normally terminated in the Marshalling Cabinet. Cabinets: Generically used within this specification; refers to all of the above.

5

General Requirements 5.1

Engineering Units All dimensions and measurements shall be in the “International System of Units” (SI), and may be followed by the equivalent value in English units between brackets. When not critical, the equivalent dimensions may be rounded off to their nearest practical value. Exception: This requirement does not apply to the vendor's standard documentation.

5.2

Environmental Conditions All cabinet equipment and wiring shall be designed for continuous operation at 50°C, and relative humidity 80% maximum (non-condensing) and 20% minimum. Commentary Note: The temperature of 50°C allows for a 35°C room ambient plus a 15°C rise within the cabinet.

5.3

Heat dissipation calculations shall be submitted for any cabinet that houses power supplies, PCs or other heat generating components. The calculations shall show that the components installed inside the cabinet will not be exposed to a temperature above their temperature rating.

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34-SAMSS-820 Instrument Control Cabinets - Indoor

Design 6.1

Style The cabinets shall be rigid and self-supporting. Unless otherwise specified, the cabinets shall be free standing, floor mounted type. Instruments and electronic accessories shall be wired in accordance with this specification. Indoor cabinets shall be made of metal. When multiple cabinets are provided, it is highly recommended that they are identical in construction and external appearance.

6.2

Drawings 6.2.1

The cabinet fabricator shall supply detailed drawings for review and approval.

6.2.2

The detailed drawings, shall as a minimum, contain the following information: a)

Cabinet fabrication drawings showing dimensions for exterior, openings, removable plates, doors and door swings, internal cabinet segregation, internal frame supports/bracing, ventilation louvers, lifting bolts, and shipping breaks.

b)

Cabinet layout drawings showing the locations and arrangements of all electronic equipment, terminal strips, fuses, plastic ducts, raceways, pushbuttons, switches, lamps, name plates, annunciators, rack-mounted equipment, power supplies, convenience outlets, lighting and grounding strips. Electronic equipment manufacturer and model numbers shall be shown.

c)

Wiring diagrams showing termination strips and all electronic interconnections, with tag names and equipment/terminal identification.

Items a) and b) shall be drawn to scale and supplied as vendor drawings for the proponent’s review and approval. Item c) shall be issued with proponent drawing numbers and completed in the Intergraph or convertible format. 6.2.3

All instruction manuals and technical information supplied with components received by the Cabinet Fabricator shall be placed in a folder or binder and shipped with the cabinet.

6.2.4

All Vendor literature and drawings shall be of sufficient size and quality to be clearly legible. Page 5 of 23

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6.3

34-SAMSS-820 Instrument Control Cabinets - Indoor

Construction 6.3.1

The cabinet shall be a NEMA Type 1 as a minimum per NEMA 250 and NEMA ICS 6 or as specified in the functional specification document.

6.3.2

Cabinets requiring heat dissipation shall be convection-ventilated.

6.3.3

Convection-ventilated cabinets shall be provided with readily accessible, removable filter screens inserted behind slotted louvers at the air inlets and outlets. Louvers and filters shall be installed within the cabinet door(s). Louvers shall not be installed on the sides or back of the cabinet.

6.3.4

Fans with suitable filters and louvers may be used within Cabinets to assist in heat removal. This can be achieved by installing a filter fan at the air inlet (typically at the bottom of the cabinet door) to blow cool air into the cabinet or by installing an exhaust filter fan at the air outlet (typically at the upper section of the door) to draw hot air out of the cabinet. The fan filter shall be easily accessible for maintenance or replacement without dismantling the fan assembly.

6.3.5

If the fans are required to dissipate heat when the HVAC is running, redundant fans shall be provided. If the fan(s) are only required to dissipate heat when the HVAC is not running, a single fan is adequate. In both cases, fan failure or over-temperature detection and alarm are required in the DCS.

6.3.6

The installation of fans on top of the cabinet should be avoided. However, if it is deemed absolutely necessary to install the fans on top of the cabinet, the fan fixtures shall be protected by an additional cover or shroud to prevent dirt and debris from falling into the cabinet.

6.3.7

Where two or more front sections are required for a Control Panel, the interior shall be an open-frame construction.

6.3.8

Cabinet support bracing shall not restrict maintenance access to chassis, modules or components. The cabinet shall be properly sized to have easy access to all installed components and wires. Accessing any of the installed components or wiring shall not require the removal of other components.

6.3.9

Each cabinet shall be provided with removable lifting rings.

6.3.10

Cabinet doors shall be full-height. All doors shall be dust-tight and reinforced against buckling. The maximum door width shall be 900 mm (36 inches) unless otherwise specified in the Purchase Order.

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Document Responsibility: Instrumentation Standards Committee Issue Date: 1 January 2013 Next Planned Update: 1 January 2017

34-SAMSS-820 Instrument Control Cabinets - Indoor

6.3.11

The marshalling cabinets, from the front surface to the surface of rear terminal blocks, shall not be more than 46 cm (18 inches) deep to provide for safe access. The preferred design is to divide a 76 cm (30 inch) deep cabinet into 38 cm (15 inch) sections with front and rear access.

6.3.12

All doors shall be capable of opening at least 90 degrees, preferably 180 degrees, and shall be equipped with mechanical stops for holding the doors open.

6.3.13

When front and rear access is provided, the central separation plate(s) shall be full height. In addition, each section of the cabinet shall be treated as a stand-alone cabinet that fully meets the requirement of this material specification document.

6.3.14

Where practically possible, control cabinets and panels should only have a single door access. Marshalling cabinets may have two door access on each side (front and rear). Exception: With the approval of the proponent, control cabinets housing subsystems (such as such as VMS, PLC, turbo machinery control, etc.) may have dual doors on both sides provided that the front and back sections are treated per Paragraph 6.3.13 above. Typically, one side would be used for marshalling and the other side for system chasses.

6.4

6.3.15

All doors shall be provided with integral lockable door handles with the same lock and key combination, unless otherwise specified on the ISS.

6.3.16

Equipment that are installed within cabinets or panels and are normally used by the operator shall be readable and operable with the operator in a standing position.

6.3.17

The inside of each door shall be equipped with a pocket suitable for holding A4 documents and/or cabinet drawings.

6.3.18

Cabinets intended for bottom cable entry shall be provided with a gland plate at the bottom of the cabinet.

Cabinet Finish 6.4.1

The exterior and interior cabinet finish shall be the Cabinet Fabricator's standard finish, unless otherwise specified in the Purchase Order. A minimum of primer, undercoat and finishing coat of enamel or lacquer is required. Electrostatic applied powder paint coatings which are then baked (such as polyester urethane) is acceptable. Page 7 of 23

Document Responsibility: Instrumentation Standards Committee Issue Date: 1 January 2013 Next Planned Update: 1 January 2017

6.4.2 6.5

6.6

34-SAMSS-820 Instrument Control Cabinets - Indoor

Interior cabinet color shall be white or of a light color such as light gray, off-white, etc., or as specified in the purchase order.

Nameplates 6.5.1

Nameplates for cabinets and panels letter height and spacing shall follow ISA RP60.6, Appendices A and C, unless otherwise specified in the purchase order.

6.5.2

Where possible, nameplate abbreviations shall be avoided. Where abbreviations are used, they shall be consistent with facility practices. ISA RP60.6 (Appendix B) shall be used to keep abbreviations consistent where facility practice is not established.

6.5.3

Control panel pushbuttons, switches, indicating lights and other through-mounted devices shall be identified with the service description on the front. The rear of the above devices shall be identified with the device tag number. The nameplates shall be permanently attached. Adhesives are allowed for indoor panels.

6.5.4

Instruments and accessories mounted inside the cabinet shall be identified with a nameplate showing the tag number. Individual rack modules are not required to have permanent nameplates attached.

6.5.5

Nameplates shall be made from laminated plastic, white-black-white (information engraved into the black core) with white surface, dull finish.

6.5.6

Each cabinet, front and rear, shall be identified with a nameplate located above each door or pair of doors. The nameplate, as a minimum, shall be the cabinet name/number as given in the cabinet drawings.

Cabinet and Panel Spare Requirements 6.6.1

Unless otherwise specified in the Purchase Order, each cabinet shall be provided with the following spare capacity to allow for future system modifications: a)

20% installed spare terminal blocks of each terminal block type used. Spare terminal blocks are to be distributed to match the layout of required spare I/O modules, field termination assemblies, relays, etc. Commentary Note: The 20% spare terminal requirement is intended to be used for the 20% spare cabling required in homerun cables. It is not

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34-SAMSS-820 Instrument Control Cabinets - Indoor

intended to be additional terminals on top of terminals used to terminate spare pairs/triads.

b)

10% spare relay bases in cabinets where there are ten relays or more. For less than ten relay installations, one spare base should be installed. Exception: The above requirement does not apply on cabinets where only one relay is installed for fan failure or alarm.

6.6.2

7

The Cabinet Fabricator shall supply a minimum of two (2) spare fuses or 10% (whichever is greater) for each type of general power and termination strip fuses used within each cabinet. This requirement includes supplying spares for fuses integral to installed electronics (i.e., flow computers, field termination assemblies, etc.).

Electrical 7.1

Power Supply 7.1.1

Power Supplies feeding process instruments shall be powered from instrument circuit power distribution panels. Each distribution strip shall be dedicated to a single voltage level. Instrumentation circuit breakers and distribution strips shall not provide power to noninstrumentation circuits. The cabinet shall be furnished with a minimum of 20% spare circuit breakers. Exception: If the cabinet is equipped with only one circuit breaker for cabinet lighting, spare breakers are not required.

7.1.2

Power wiring for field instruments, all input and output points, twowire analog transmission loops, field switch contacts, etc., shall be individually fused and provided with a means of disconnecting the power without disturbing terminated wiring (e.g., knife-switch-type terminal blocks). Daisy chaining of external loop power using wires or wire crimps is not acceptable. Exceptions: 1)

Wiring connected to I/O modules or interfaces containing individual current-limiting circuit protection does not require fuses.

2)

Low Voltage wiring connected directly to I/O. (See paragraph 7.6)

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34-SAMSS-820 Instrument Control Cabinets - Indoor

Commentary Note: Fuse application, location, and ampacity ratings must be properly sized and coordinated, taking into account the maximum expected load at the maximum operating temperature of the cabinet (50°C).

7.1.3

Unless otherwise specified, equipment shall operate at the supply voltages shown in Table 1. Table 1 – Supply Voltage System/Device

Nominal

Tolerance

NEC Class

Annunciator Power Shutdown and Isolation System including relay coils Field Switch Contacts

24 VDC

21 - 28.2 VDC

1 or 2

125 VDC 120 VAC, 60 ± 2 Hz

113 - 141 VDC 110 - 126 VAC

1 or 3 1 or 3

Analog Signal (Loop Power)

24 VDC (4-20 mA) 24 VDC 120 VAC, 60 ± 2 Hz

21 - 28.2 VDC 21 - 28.2 VDC 110 - 126 VAC

1 or 2 1 or 2 1 or 3

Instrumentation Power Note:

The basis for the upper DC voltage variations is due to installations where battery backup is used without voltage suppression and the batteries receive periodic charging.

7.1.4

Where multiple on-line DC power supplies are connected to a single power bus, diode auctioning shall be used to facilitate load balancing in the event of a single power supply failure. Where multiple DC power supplies are an integral part of a manufacturer's standard product, the manufacturer's standard method of load sharing shall apply.

7.1.5

Supplies to DC instrument loads: Voltage stabilization shall be provided to maintain the output voltage within tolerable limits of the loads served.

7.1.6

Power supplies shall be identical whenever possible for interchangeability and spare part requirements.

7.1.7

Power supply outputs shall be individually fused or protected by dedicated circuit breakers.

7.1.8

Power Supply terminal block distribution wiring shall not be daisychained using wires or crimp connectors. Jumper bars or preformed jumper combs designed for the specific terminal blocks being used are acceptable methods of distributing power supply wiring.

7.1.9

Power supply load calculations shall be provided by the vendor showing a minimum 10% spare power capacity on the running power supply and its redundancy.

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Document Responsibility: Instrumentation Standards Committee Issue Date: 1 January 2013 Next Planned Update: 1 January 2017

7.1.10

7.2

34-SAMSS-820 Instrument Control Cabinets - Indoor

The cabinet shall be equipped with a common power supply fault/failure alarm switch. The switch should be connected to the DCS or panel front for alarming.

Wire Installation 7.2.1

Splices are not permitted in wiring. When wiring must be extended, connections shall be made via terminal blocks.

7.2.2

Twist-on wire nut connectors shall not be used for making any electrical instrumentation terminations.

7.2.3

Segregation of parallel wiring internal to cabinets shall adhere to the following Table 2. All dimensions are shown in millimeters. Table 2

0 0 0 0 25 25 150 75 150 75

4-20 mA Analog 24 VDC 0 0 0 0 0 0 75 25 75 25

24 VDC Power/ Digital 25 25 0 0 0 0 25 0 75 0

0 0

0 0

0 0

Signal Category

Milli Volt T/C RTD

Milli Volt T/C RTD 4-20 mA 24 VDC 125 VDC 120 VAC Copper Network Cable

125 VDC

120 VAC

150 75 75 25 25 0 0 0 0 0

150 75 75 25 75 0 0 0 0 0

Copper Network Cable 0 0 0 0 0 0 50 25 75 50

50 25

75 50

0 0

Notes: 1)

Upper Value Spacing is for wires in plastic ducts.

2)

Lower Value Spacing is for wires separated by:

a)

One metal conduit or

b)

A 1/16-in. thick grounded steel divider.

3)

Voltages shown are nominal.

7.2.3.1

Separate plastic ducts are preferable for all Signal Categories that require separation for organization and noise reduction. Signal Categories with upper values of zero separation may be mixed in a plastic duct. Signal Categories shall not be mixed within any single multicore cable. Page 11 of 23

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Example: 24 VDC digital and 24 VDC 4-20 mA may be run in the same plastic duct, but not within a single multipair cable.

7.2.3.2

7.3

7.4

Wiring that is required to be segregated shall cross at right angles and the spacing shall be maintained as close as practicable to that shown in Table 2.

Wire Specifications 7.3.1

General 120 VAC power wiring shall be minimum 14 AWG stranded copper, UL listed and PVCor XLPE insulated. Wire insulation shall be rated for 600 volts, 75°C, minimum.

7.3.2

Electronic signal wire shall be UL listed, stranded copper, minimum size 18 AWG, 300 V for single conductors or a minimum 20 AWG, 300 V for multicore cable (assuming Class-2 circuits per NEC). Wire insulation shall be XLPE PVC, or PTFE, with a minimum temperature rating of 75°C. Special electronic signal wires shall be as described in the Purchase Order.

Wiring Methods 7.4.1

Cabinets containing electronic equipment with field inputs/outputs (I/O) (e.g., field termination assemblies, I/O modules, etc.) shall have the I/O device pre-wired to: 1)

intermediate terminal strips within the same cabinet shipping section, or;

2)

to intermediate terminals within the same building by the use of manufactured multi-conductor cable and plug connectors. Commentary Note: Field wiring shall be terminated on the intermediate terminal strips (by others). This process makes it easier to land field wires on-site and minimizes possible damage to vendor equipment during termination of field wires. Exception: See 7.6 for low voltage wiring exceptions to the use of intermediate terminal strips.

7.4.2

Exposed electrical connections with voltages greater than nominal 48 volts AC/DC shall be shrouded by transparent, removable, insulating plastic covers (or equivalent). Page 12 of 23

Document Responsibility: Instrumentation Standards Committee Issue Date: 1 January 2013 Next Planned Update: 1 January 2017

7.4.3

34-SAMSS-820 Instrument Control Cabinets - Indoor

When screw-type terminals are provided on instruments and other electrical devices, solderless crimp/compression connectors shall be used for connecting stranded copper conductors. Insulated ring lugs, locking-fork or flanged- fork connectors, specifically designed to hold the connector on the terminal in the event of loosening of the terminal screw, shall be used on all such connections. Commentary Note: Screw-type terminals are defined as those in which the termination method involves the direct compression of the conductor by the underside of the screw head, and which do not contain the conductor within a clamp or yoke.

7.4.4

7.5

7.6

When a cabinet contains CPU and I/O modules, the racks shall be arranged so that the processor modules are installed in the top and the I/Os are installed next to the processor modules or beneath them.

Annunciator Wiring 7.5.1

When specified, annunciator shall have a horn relay wired to terminals for connection to the remote horn system.

7.5.2

Annunciator(s) shall have a lamp/horn test, acknowledge and reset button unless otherwise specified in the Purchase Order.

Wiring for Millivolt, Microamp, Pulse and Frequency Signals Wiring for millivolt, microamp, pulse and frequency signals under 1 Volt such as thermocouples, resistance temperature detectors (RTD), vibration elements, analyzer elements, thermistor elements and transmitters with pulse outputs may be directly connected to the I/O unless otherwise specified in the Purchase Order.

7.7

Terminal Strips 7.7.1

The termination method shall be channel (rail)-mounted terminal blocks.

7.7.2

Terminal strip spacing shall allow ample room for plastic wire ducts and permit lacing of cables, and fanning of individual wires to termination points. Each terminal strip shall be labeled above or below with the terminal strip number, as shown on wiring diagrams. Terminals for similar (AC or DC) current service shall be grouped together and physically separated from terminals for different service by means of dividers, separate mounting rails or separate enclosures.

7.7.3

Standoffs for terminal strips are preferred to bring the terminal blocks forward to be flush with the top of the plastic wire duct. This wiring Page 13 of 23

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34-SAMSS-820 Instrument Control Cabinets - Indoor

method assures that all wires can be accessed without interference from other wires as the wire duct is filled.

7.8

7.7.4

Where special cases of mixed ESD / Non-ESD signals occur in one cabinet or control panel (e.g., Solid State / Relay Control Cabinets or Control Panels with ESD pushbuttons ), terminal strips for Emergency Shutdown (ESD) wiring shall be completely separate from all other wiring including power, control and instrumentation.

7.7.5

Wiring for a given instrument loop shall be terminated on adjacent terminals on the terminal strip in order to organize and group all loop wiring.

7.7.6

Terminals for various types of general wiring (AC or DC), annunciator points and signal wiring shall be separately grouped and separated by dividers.

Terminal Blocks 7.8.1

No more than two bare wires shall be connected to each side of a single terminal block.

7.8.2

All terminal blocks shall be channel (rail)-mounted, strip-type, with a tubular box clamp connector and compression bar or yoke for wire termination. As a minimum, the thickness of the terminals shall be 5 mm or higher. All terminals shall be numbered on both sides.

7.8.3

Terminals shall be made of fire retardant, halogen free, high strength material such as polyamide or equivalent in accordance with UL 94, V0. Brittle materials such as melamine shall not be used.

7.8.4

A fused terminal block shall have a blown-fuse indicator. This may be a Light Emitting Diode (LED), visual sight indication through a port, or equivalent.

7.8.5

The disconnect levers for fused terminals and knife-switch terminals shall be hinged.

7.8.6

Wires terminated on these terminal blocks shall not have the bare ends coated with or dipped in solder (“tinned”). However, termination of wiring which has individual strands of the copper conductor tinned during manufacture (typical of shield drain wires or for corrosion protection) is acceptable.

7.8.7

Direct termination of the bare wire end is acceptable. The terminal block must be suited for the wire size. The use of crimp-on ferrules Page 14 of 23

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shall follow the manufacturer's guidelines and the following: a)

One or two wire ferrule is acceptable. However, the use of ferrules to daisy chain is not acceptable.

b)

Only one ferrule shall be connected to each side of a single terminal block.

c)

Ferrules shall be provided with plastic insulating collars.

7.8.8

Terminal blocks with a narrow, recessed screw entrance which require a special screwdriver or wrench may be used only if the insulation material is per Paragraph 7.8.3.

7.8.9

Multiple-deck and spring type terminal blocks shall not be used. Exception: When provided as an integral part of manufactured electronic equipment, multiple-deck terminal blocks are allowed, but never for direct termination of field cabling.

7.9

Wire Ducts and Looms 7.9.1

Plastic wire ducts with removable covers shall be installed in cabinets as required to provide a means of routing and organizing wiring. A minimum of 50 mm shall be maintained between the duct and terminal strips. Wire markers shall be completely presented without being obscured by the duct.

7.9.2

The maximum conduit/plastic wire duct fill (including spare capacity) shall not exceed the heat requirements of NFPA 70 Section 300.17.

7.9.3

In addition to the above, the maximum plastic wire duct fill (including spare capacity) shall not exceed 75% of its depth.

7.9.4

Plastic wire ducts shall be mounted using screws. Double-sided tape is unacceptable.

7.9.5

Where space limitations preclude the use of plastic wire ducts, wiring shall be neatly loomed and secured with plastic spiral wrapping or tiewraps and anchors. Wiring between movable parts such as doors shall be installed in flexible hoses.

7.9.6

Loomed wiring shall not be installed near sharp-edged surfaces.

7.9.7

Wiring shall not be threaded through undressed access holes. Glands or protective grommets shall be used. Page 15 of 23

Document Responsibility: Instrumentation Standards Committee Issue Date: 1 January 2013 Next Planned Update: 1 January 2017

7.10

34-SAMSS-820 Instrument Control Cabinets - Indoor

7.9.8

Vendor-installed cables shall be supported and provided with a strainrelief mechanism for cable connectors.

7.9.9

Wire ducts for ESD wiring shall not contain any other types of wiring.

Wire Color Coding AC Power Supply: DC Power Supply:

Hot Neutral Ground Negative Positive

Black White or gray Green or green with yellow tracer Black Red

If the wire insulation cannot be color-coded as above, the wire must be sleeved with the required color. The sleeve shall cover from the cut insulation end to a point past where the conductor enters the plastic wire duct or a minimum of 4 inches, whichever is less. Sleeves shall not be used over green insulation. Blue color shall not be used except in intrinsically safe circuits. 7.11

Wire Tagging 7.11.1

Cables with connector plugs shall be tagged at each end. Each cable tag shall have two labels. The first label (closest to the plug connector) shall identify the device and socket to which the plug is to be connected. The second label shall identify the device and socket to which the opposite end of the cable is connected. The two tags may be combined into one tag with sufficient separation between the two labels.

7.11.2

The interconnecting wiring shall be tagged at each end with two identification tags (or the two may be combined into one tag with sufficient separation between wire numbers). The first tag (closest to the end of the wire) shall identify the terminal number to which the wire is physically connected. The second tag shall identify the terminal number to which the opposite end of the wire is connected. Commentary Notes: Where jumpers are installed between terminal blocks in the same row or column and are clearly visible, wire tagging is not necessary. Identification shall be in accordance with designations shown on instrument loop diagrams (ILDs). Where wires terminate on instrument or device terminals, the instrument tag number and terminal designation (+) or (-) (if applicable) will be used in lieu of terminal strip identification.

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Exceptions:

7.11.3

1)

Alternate wire tagging schemes, which conform to established local practice, may be used for extensions to existing facilities with the prior approval of the proponent.

2)

Vendor Standard wire tagging of interconnecting wiring is allowable provided approval is granted by the proponent.

Wire tag information shall be permanently marked in block alphanumerics or typed on tubular; heat shrinkable, slip-on sleeves. Wrap-around, snap-on or self-adhesive markers shall not be used. Where shrink fit cable markers cannot be installed over pre-made cable and connectors, a suitable tie-wrap or equivalent type permanent marker shall be used. Exceptions: 1)

Alternate wire tagging schemes, which conform to established local practice, may be used for extensions to existing facilities with the prior approval of the proponent.

2)

Plastic sleeves that are specifically designed to fit on a specific wire gauge and come with pre-printed alpha/numeric inserts (such as Grafoplast Trasp System) may be used for wire tags with prior approval of the proponent.

7.11.4

Wire and cable tags shall not be handwritten.

7.11.5

Wire tags shall be installed and oriented such that the tags are easily read. (Upside down or covering of tag information by plastic duct covers is not acceptable).

7.11.6

Spare pairs/triads in multi-pair/triad cables shall be labeled “SPARE” in addition to the destination and source terminal numbers. All spares are to be terminated.

7.11.7

Per NEC 310-120, all conductors and cables shall be marked to indicate the following information:

7.11.8

1)

Maximum rated voltage for which the conductor was listed,

2)

The letter designators for type of wire or cable,

3)

Manufacture's name or trade mark,

4)

The AWG size or circular mil area.

All cable ties used inside of cabinets shall be weather resistant nylon cable ties with a stainless steel barb. The cable tie shall have a Page 17 of 23

Document Responsibility: Instrumentation Standards Committee Issue Date: 1 January 2013 Next Planned Update: 1 January 2017

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maximum continuous use temperature rating of 85ºC or higher, e.g., Panduit Dome-Top Barb Ty Cable Ties - Weather Resistant, or equivalent. 7.12

7.13

Terminal Coding 7.12.1

Each row of terminals shall be clearly identified with an alphanumeric label. Each row of ESD terminals shall additionally be marked to show ESD service.

7.12.2

In addition to 7.12.1, each row of Power supply and bus terminals shall be marked with voltage type and level. (e.g., +24 VDC, or 120 VAC, etc.)

7.12.3

Numerical terminal identification and coding shall be assigned sequentially (in ascending order, from top to bottom or left to right). Each vertical row and group of rows shall be labeled separately.

Relays 7.13.1

Relays shall be of the electromechanical, dust-tight, 11-pin (3PDT) or 8-pin (DPDT) plug-in type. Exceptions: 1.

Relays provided as an integral part of manufactured electronic equipment installed within cabinets may use that manufacturer's standard offering.

2.

For hermetically sealed relays, 4PDT, 14-pin relays may be used provided that no more than two contacts are used.

7.13.2

Each relay shall be supplied with a bracket or holding clips to prevent it from falling off the base (socket). Using relays that are permanently attached to the relay base is not acceptable.

7.13.3

A dedicated relay base shall be provided for each relay. Using multisocket modules that can accommodate more than one relay is not acceptable.

7.13.4

The mounting socket shall be provided with a plastic label, color black-white (relay number engraved into the black core with white surface, dull finish). The relay tag shall not be mounted directly on the relay and shall be visible when the relay is installed. The relay number shall be shown as presented in the detailed cabinet drawings.

7.13.5

DIN rail mounted relay bases are preferred. Page 18 of 23

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7.13.6

Coil voltage shall be as specified in the Purchase Order. Pull-in voltage shall be 80% or less of nominal voltage.

7.13.7

All relays shall be provided with suppression diodes.

7.13.8

Relay configuration and pertinent operating information shall be imprinted on the case.

Push Buttons and Lights Push buttons and lights shall be industrial quality. Push buttons shall have protective mechanisms to prevent accidental activation as required by the detailed design specification. Long-life type lamps or LED cluster lamps shall be used. It shall be possible to access the lamp bulbs from the front for replacement. The color of the pushbuttons or lights shall be green for “ON”/”OPEN” and red for “OFF/”CLOSE” positions. Only screw terminals shall be provided on push buttons. Exception: Existing facilities that currently deviate from the above light color specification may use other conventions in order to keep the lighting philosophy consistent within the facility.

7.15

Lamp Test Facilities For all control panels with indicating lights, a lamp test button shall be provided per panel. Exceptions: LED or other lamps integral to a manufacturer's electronic instrumentation do not require the lamp test button. Power status-indicating lights that are normally “on” where it is not desirable to “cross-feed” lamp test power from an alternative source (Such as UPS power status).

7.16

Circuit Breakers and Fuses 7.16.1

Individual circuit breakers shall be provided for each power supply unit.

7.16.2

Fuses and circuit breakers shall be readily accessible for maintenance with sufficient clearance from obstructions.

7.16.3

Tandem type (dual) circuit breakers in a single molded case shall not be used, as the failure of one breaker requires complete replacement of Page 19 of 23

Document Responsibility: Instrumentation Standards Committee Issue Date: 1 January 2013 Next Planned Update: 1 January 2017

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the assembly. 7.16.4

7.17

7.18

Circuit breakers shall be installed in a manner that allows replacement of a breaker without disruption to adjacent breakers. Circuit breakers shall not be interconnected using wire jumpers, comb jumpers or bridges of any type.

Marshalling Cabinet Shielding 7.17.1

Cable shields must have a single, continuous path to ground. Ground loops and floating shields shall be avoided. Shields shall be consolidated and ultimately connected to the Instrument Circuit Ground Bar as detailed in paragraph 7.18.6.

7.17.2

Shield drain wires shall not be daisy-chained using bare wires or crimp connectors to the ground connection.

7.17.3

Cable shields must have a continuous path to ground. Acceptable methods of consolidating shields are as follows: a)

Special grounding terminals in intimate contact with an electrically isolated DIN Rail.

b)

Terminal Block jumper bars designed for the selected terminal blocks.

c)

Preformed jumper combs designed for the selected terminal blocks.

d)

Electrically isolated bus bars running parallel to terminal blocks.

Grounding 7.18.1

Both safety ground and instrumentation circuit ground must conform to NEC, Article 250. Grounding system recommendations and requirements provided by manufacturers of instrumentation and control systems (e.g., Distributed Control Systems) shall be followed.

7.18.2

Separate, electrically isolated grounding bars shall be provided, as required.

7.18.3

All ground buses shall be made of a solid copper measuring the following nominal dimensions 5mm x 40 mm x (y length), suitably drilled and tapped for screw terminals and wire lugs, or fitted with screw-type compression lugs. Commentary Note: The ground bus dimensions in Paragraph 7.18.3 are nominal.

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Buses that are slightly different in sizes are acceptable provided that they are sized for the worst case ground currents.

7.18.4

The preferred location of the ground bus bars is at the bottom of the cabinet.

7.18.5

A No. 2 AWG screw-type compression lug shall be provided on both end of each ground bar for interconnection with the Master Instrument Ground or Master Safety Ground.

7.18.6

The ground bus bars shall be labeled and wired as follows: “AC SAFETY GROUND” for all exposed metal surfaces of cabinets, racks, chassis GND connections, etc. Individual wiring interconnections between the internal components and the bus shall be minimum 12 AWG copper wire, green with yellow tracer insulation. This bus shall be directly bolted to the cabinet without the use of insulators. “INSTRUMENT CIRCUIT GROUND” for connecting cable and wire shields and DC Common. Interconnections between shield consolidation points and the bus bar shall be minimum 12 AWG copper wire, with green insulation. This bus bar shall be electrically insulated from the cabinet structure.

7.18.7 When provided, AC power receptacle outlets shall be grounded using ground wire terminated on the receptacle grounding terminal. (e.g., A receptacle utilizing the faceplate as a ground path is not permitted.) 7.18.8

7.19

All enclosure doors and subpanels shall be electrically bonded to main enclosure frame by a braided ground strap (wire size #8 AWG or equivalent).

Lighting, Convenience and Power Distribution Receptacle Outlets 7.19.1

Cabinet lights shall be installed where practical and necessary, as specified in the Purchase Order.

7.19.2

If specified, cabinet lights shall be 120 Volt, 60-watt incandescent lamps, size IEC, type E27 or ES (Edison Medium Screw Base) fitting or 15-watt minimum industrial grade, fluorescent lighting fixture(s) oriented in such a manner that the majority of the interior portions of the cabinet are illuminated.

7.19.3

Incandescent lamps shall have a guard to help protect the lamp from accidental breakage. Fluorescent lamps shall have clear plastic sleeve guards to help contain broken glass in case of an accident. Page 21 of 23

Document Responsibility: Instrumentation Standards Committee Issue Date: 1 January 2013 Next Planned Update: 1 January 2017

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7.19.4

When specified in the Purchase Order, convenience outlets shall be duplex-type and rated at 120 VAC, 10 amp as a minimum.

7.19.5

Interior lamps and convenience outlets shall be wired to separate thermal/magnetic circuit breakers which shall be powered from a proponent-furnished AC distribution panel, independent of the UPS power supply.

7.19.6

A switch in the cabinet (in addition to the circuit breaker) shall control each lamp where the lamp is installed. Automatic door switches for lamps are allowed.

Testing and Inspection The items manufactured to this specification are subject to verification by the proponent’s Inspection representative, per the proponent’s Inspection Requirements Form attached to the Purchase Order. The Cabinet Fabricator shall verify the operation of all instrumentation and controls. Documented test procedures shall be submitted to the proponent for approval not less than thirty (30) days before commencement of test. Tests shall include, but shall not be limited to: a)

A function test of all electronic instruments and electric control circuits and relays.

b)

Visual inspection to verify compliance with requirements of this specification.

c)

Complete wiring check with verification that terminal and wiring code conforms to cabinet design drawings.

d)

A certificate of compliance to the RFI requirements of IEC 61000-4-3, Level 3. The certificate(s) shall be for either the entire cabinet or for all the electronic equipment installed within the cabinet.

EMI/RFI Interference (Radiated Susceptibility) The cabinet electronic equipment shall perform within the normal limits without loss of function or degradation of performance when subjected to radiated electromagnetic fields in accordance with IEC 61000-4-3, Level 3, (at a 10 V/m power level), with cabinet doors open. If certificates are not available, the equipment in the cabinet shall function within the normal limit when tested with a 5 watt radio transceivers operating at 5 Watts within the frequency ranges, 50-174 MHz, 406- 470MHz, and 800-870 MHz and held at a distance of 1.0 meter from the cabinet, with cabinet doors open.

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34-SAMSS-820 Instrument Control Cabinets - Indoor

Shipment Adequate precautions should be exercised to prevent damage during shipment. All openings shall be sealed and threaded connections shall be protected with molded plastic screwed plugs or caps. The cabinet crating shall be in accordance with good shipping practice; with the cabinet/panel adequately protected against corrosion, mechanical damage or marring of the cabinet finish. Before crating, the cabinet/panel shall be boxed or covered with a suitable plastic sheet. Each panel box or crate shall be clearly identified with panel and order numbers and marked to show upright position.

1 January 2013

Revision Summary Revised the “Next Planned Update”. Reaffirmed the content of the document, and reissued with minor revisions for clarification of some of the requirements in response to questions received from various project teams.

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