Safe Work Practices Electrical Safety
Short Description
Swp on electrical safety which is applicable in KNPC refinary...
Description
PRINTED COPY NOT CONTROLLED
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
………………………………………………………………………
4
……………………………………………………………..
4 4
3.1 EMPLOYEE INVOLVEMENT
4
3.2 ELECTRICAL SAFETY IMPROVEMENT PROCESS
5 5
……………………………………………
8
ELECTRICAL TECHNOLOGY ……………………………………… …………………………………………… ……
8
5.2 OPERATING OP ERATING PROCEDURES AND SAFE PRACTICES ……………….
8
5.2.1 WORKING ON OR NEAR ENERGIZED ELECTRICAL EQUIPMENT ..
9
5.1
5.2.2 ELECTRICAL POWER ISOLATION …………………… ……………………..
10
5.2.3 JOB AND TASK PLANNING ……………………………………… ………………………………………………. ……….
10
5.2.4 NO-VOLTAGE TESTING ……………………………………… ………………………………………………….. …………..
11
5.2.5 PERSONAL PROTECTIVE EQUIPMENT ……………………………….
13
5.2.6 TROUBLE SHOOTING ……………………………………… …………………………………………………… ……………
13
5.2.7 DISMANTLE AND REMOVE/REARR REMOVE/REARRANGE ANGE WORK …………………..
13
5.2.8 DOCUMENTATION DOCUMENTATION AND EQUIPMENT LABELLING …………………
14
5.2.9 EXCAVATIONS / PENETRATIONS ………………………… ……………………………………. ………….
15
5.2.10 CRANE AND MOBILE EQUIPMENT……… EQUIPMENT………………………………… ………………………….. ..
14
5.2.11 WATER / STEAM CLEANING …………………………………… ………………………………………… ……
15
5.2.12 POWER DISTRIBUTION SWITCHING ………………………… ……………………………… ……
16
5.2.13 MANAGEMENT OF CHANGE – TECHNOLOGY …………………….
16
5.2.14 MANAGEMENT OF ELECTRICAL HAZARDS …………………………
16
5.3 PERSONNEL …………………………………… ………………………………………………………………….. ……………………………..
20
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 2 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
………………………………………………………………………
4
……………………………………………………………..
4 4
3.1 EMPLOYEE INVOLVEMENT
4
3.2 ELECTRICAL SAFETY IMPROVEMENT PROCESS
5 5
……………………………………………
8
ELECTRICAL TECHNOLOGY ……………………………………… …………………………………………… ……
8
5.2 OPERATING OP ERATING PROCEDURES AND SAFE PRACTICES ……………….
8
5.2.1 WORKING ON OR NEAR ENERGIZED ELECTRICAL EQUIPMENT ..
9
5.1
5.2.2 ELECTRICAL POWER ISOLATION …………………… ……………………..
10
5.2.3 JOB AND TASK PLANNING ……………………………………… ………………………………………………. ……….
10
5.2.4 NO-VOLTAGE TESTING ……………………………………… ………………………………………………….. …………..
11
5.2.5 PERSONAL PROTECTIVE EQUIPMENT ……………………………….
13
5.2.6 TROUBLE SHOOTING ……………………………………… …………………………………………………… ……………
13
5.2.7 DISMANTLE AND REMOVE/REARR REMOVE/REARRANGE ANGE WORK …………………..
13
5.2.8 DOCUMENTATION DOCUMENTATION AND EQUIPMENT LABELLING …………………
14
5.2.9 EXCAVATIONS / PENETRATIONS ………………………… ……………………………………. ………….
15
5.2.10 CRANE AND MOBILE EQUIPMENT……… EQUIPMENT………………………………… ………………………….. ..
14
5.2.11 WATER / STEAM CLEANING …………………………………… ………………………………………… ……
15
5.2.12 POWER DISTRIBUTION SWITCHING ………………………… ……………………………… ……
16
5.2.13 MANAGEMENT OF CHANGE – TECHNOLOGY …………………….
16
5.2.14 MANAGEMENT OF ELECTRICAL HAZARDS …………………………
16
5.3 PERSONNEL …………………………………… ………………………………………………………………….. ……………………………..
20
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 2 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
5.3.1 TRAINING AND PERFORMANCE ……………………………………… ………………………………………..
20
5.3.2 CONTRACTOR ADMINISTRATION …………………… …………………………………….. ………………..
21
5.3.3 INCIDENT INVESTIGATION AND REPORTING …………………… ……………………….. …..
21
5.3.4 MANAGEMENT OF CHANGE – PERSONNEL ………………………….
21
5.3. 5.3.5 5 EMER EMERGE GENC NCY Y PLAN PLANNI NING NG AND AND RESP RESPON ONSE SE ………… ……………… ………… ………… ……… …
21
5.4 FACILITIES FACILITI ES ……………………………………… ……………………………………………………………………. …………………………….
22
5.4. 5.4.1 1 QUAL QUALIT ITY Y ASSU ASSURA RANC NCE E ………… ……………… ………… ………… ………… ………… ………… ………… ………… ……..
22
5.4.2 PRESTART-UP SAFETY REVIEW ……………………… ……………………………………….. ………………..
22
5.4.3 MECHANICAL INTEGRITY ……………………………………… ……………………………………………….. ………..
22
5.4.4 MANAGEMENT OF SUBTLE CHANGE – FACILITIES …………………
23
……………………………………………
23
6.1
SUPPORT RESOURCES …………………………………… ………………………………………………….. ……………..
23
6.2
MANAGEMENT RECORDS ……………………………………… ………………………………………………… …………
24
6.3
AUDIT REQUIREMENTS… REQUIREMENTS…………….. ………….. ………………………………… …………………………………….. …..
24
6.4
PROCEDURE RENEWAL PROCESS ………………………………… …………………………………….. …..
24
6.5
DEVIATION PROCESS ……………………………………… ……………………………………………………… ………………
24
6.6
TRAINING AND COMMUNICATION REQUIREMENTS REQUIREMENTS ………………..
24
6.7
CONTACT ……………………………………… …………………………………………………………………….. ……………………………..
24
25 27 28
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 3 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
1.0
SCOPE: This document supersedes chapter # 14 Electrical Safety” and a part of chapter # 1 “Area Classifications” of KNPC Safety Regulations. This document provides mandatory requirements and advisory guidance for establishing, sustaining, and improving the procedures and practices used to manage interaction with electrical equipment and systems to prevent injury, interruptions to operations, and impact on equipment critical to process safety. This procedure applies to all KNPC sites.
2.0
REFERENCES: KPC Corporate HSE standard – Electrical Safety Management: Document # 30 Safety Rules for the Work on Electrical Power System (Document Reference: MAA-ELAC-03-0943) Procedure for Multi-Lock System in KNPC Refineries (Document Reference: MAA-ELAC-03-1330) Procedure for Temporary Electrical Power and Lighting Circuit Wiring Connection (Document Reference: MAA-ELAC-03-1491)
3.0
MANAGEMENT RESPONSIBILITIES: KNPC management has the responsibility to implement this document on Safe Work Practices on Electrical Safety. 3.1
EMPLOYEE INVOLVEMENT: Team Leader Elect.& A/C Maint. shall on an ongoing basis, solicit participation and input from employees regarding ideas for improving and strengthening site electrical safety programmes and procedures using safety meetings and safety promotion programs. Effective electrical safety programmes should involve everyone in individual and collective efforts to manage electrical safety. Recognising that all employees are exposed to potential electrical hazards, it is important that Team Leader Elect.& A/c Maint. provides for and encourages a broad spectrum of employee involvement in the design, implementation, and ongoing operation of the site’s electrical safety programme.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 4 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
3.2
ELECTRICAL SAFETY IMPROVEMENT PROCESS: Team Leader Elect.&A/c Maint. shall establish an electrical safety improvement process as part of their overall safety and occupational health management process. The electrical safety improvement process shall include the following activities: Developing, documenting, and issuing site electrical safety procedures and practices Providing training on safe electrical work practices appropriate for job responsibilities for all site personnel. Developing and implementing improvement plans utilising Incident Investigation & Reporting System based on both on-site and off-site electrical incident findings and recommendations. Identifying and promoting electrical facility improvement opportunities through the use of inherently safer electrical technology as specified by KNPC standards/SHELL design engineering practices. Conducting safety performance audits and work permit audits for compliance with site electrical safety procedures and practices, analysing audit results and preparing reports for the management, acknowledging strengths, and recommending upgrades and corrective actions Providing site co-ordination for electrical safety, particularly where different crafts are involved. Networking with other sites as appropriate via internet, intranet, outlook mail, correspondences with other parties, consultants, refineries, contractors etc. •
•
•
•
•
•
•
4.0
DEFINITIONS: 4.1
AN AUTHORISED PERSON: The person who: A. is aged over 21 years, B. has sufficient technical knowledge of working on High and Low Voltage Equipment, C. has an intimate knowledge of the whole or part of the Company Power System, D. is at the level of KNPC Electrical Supervisor and above or equivalent levels of Contractor manpower,
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 5 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
E.
4.2
holds a Certificate of Authorization signed by Team Leader, Electrical & A/C Maintenance Division or Senior Electrical Engineer of KNPC. The certificate shall indicate the following: i. The type of work the Authorized Person is authorized to carry out such as working on Equipment rated up to 13.8KV including any critical Equipment (i.e. UPS, Battery charger etc) ii. The section of Company’s Power System to which it applies.
A COMPETENT PERSON: The person who: A. is aged over 21 years, B. has sufficient technical knowledge and experience to avoid danger, C. is at the level of KNPC Electrical Foreman and above or equivalent levels of Contractor manpower, D. holds a Certificate of Competency signed by Team Leader, Electrical & A/C Maintenance Division or Senior Electrical Engineer of KNPC. The certificate shall indicate the following: i. The type of work the Competent Person is permitted to carry out such as working on Equipment rated up to 3.3KV excludes any load transfer operation and working on critical Equipment (i.e. UPS, Battery charger etc) ii. The section of Company’s Power System to which it applies.
4.3
ELECTRICAL SHOCK INJURY: An injury that results from electrical, thermal, acoustic, or radiation energy released at the moment of an incident.
4.4
PROCEDURE: A documented method or process of carrying out work activity that is aligned with applicable national regulations and standards and is also aligned with KNPC policies, standards, and guidelines.
4.5
RESIDUAL CURRENT DEVICE (RCD) OR EARTH LEAKAGE CIRCUIT BREAKER (ELCB): An electrical safety device used to protect people from electric shock injuries by sensing the leakage of currents to ground and de-energizing the circuit before a serious injury is likely to occur.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 6 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
4.6
WORKING NEAR” ENERGISED ELECTRICAL EQUIPMENT:
“
Any activity involving crossing or working inside the shock hazard Limited Approach Boundary and/or crossing or working within the Flash Hazard Boundary established by hazard analysis. 4.7
WORKING ON” ENERGISED ELECTRICAL EQUIPMENT:
“
Any activity involving crossing or working inside the shock hazard Prohibited Approach Boundary or coming into contact with exposed, energised electrical conductors or circuit parts with any part of the body or with tools, probes, or test equipment, regardless of the personal protective equipment a person is using. 4.8
LIMITED APPROACH BOUNDARY: This is a boundary that must be crossed only by competent/authorized persons, or by incompetent persons escorted and supervised by a competent/authorized person.
4.9
RESTRICTED APPROACH BOUNDARY: For circuit parts and conductors without IP 20 equivalent design, only competent/authorized persons, who must use shock protection techniques and equipment, will cross this boundary. Note: IEC 60529 IP 20 design, or equivalent, provides guarding, shrouding, or other means to prevent finger contact with bare conductors and circuit parts.
4.10 PROHIBITED APPROACH BOUNDARY: For circuit parts and conductors without IP 20 equivalent design, this boundary will be crossed only by competent/authorized persons who must use the same protection, procedures and techniques of shock protection as when direct contact is made with a live part.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 7 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
5.0
STANDARDS / GUIDELINES: 5.1
ELECTRICAL TECHNOLOGY: Technologies that eliminate exposure to electrical hazards are the first line of defence in avoiding electrical incidents. Technologies that reduce the frequency and/or severity of potential exposures, used in conjunction with safe work practices, shall be considered a second line of defence. Personal protective equipment shall be considered the last line of defence. Project department, Engineering & Maintenance department, in association with SH&E department, through consultants shall ensure that following solutions are considered in the project design and selection of new equipment: Minimising personnel exposure to electrical hazards through process and equipment design and specification, installation details, maintenance, and operation of electrical equipment and systems. Guarding exposed parts operating at >50 VOLTS within enclosures to prevent inadvertent contact. Specifying electrical devices with shrouded terminals and conductors to an ingress protection rating of IP20 (finger-safe) or greater as defined in IEC 60529 to reduce the possibility of inadvertent contact with energised parts •
•
•
5.2
OPERATING PROCEDURES AND SAFE PRACTICES: Team Leader Elect.& A/c Maint., in association with other responsible division shall ensure that the sites have electrical procedures that are easily accessible and up-to-date. These procedures shall be developed using perceived risk-assessment process and shall contain safe practices necessary to identify and manage the electrical hazard exposure. In addition to internal operations, these procedures shall cover normal and emergency operations associated with the electrical supply utility and / or neighbouring facilities. Procedures shall be reviewed and reauthorized at intervals not to exceed three years and shall be consistent with national regulations. The review shall include individuals involved in the execution of the specific task to which the procedure pertains.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 8 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
5.2.1 WORKING ON EQUIPMENT:
OR
NEAR
ENERGISED
ELECTRICAL
Team Leader Electrical & A/c Maint. shall demonstrate commitment to minimize the time of exposure to electrical circuits and conductors energized at voltage >50V, including the contact of tools or any part of the body, regardless of personal protective equipment used. Work within the Prohibited Approach Boundary can be performed only if all of the following mandatory requirements are met: a) Only authorized personnel trained on the specific task and the hazards involved are permitted to perform work on energized conductors. b) Team Leader Electrical & A/c Maint. can authorize the work on energized conductors through blanket approvals. c) Specific job plans have been written for the task and available in “Standard Maintenance Manual”. Voltage testing can be performed only if all of the following mandatory requirements are met: a) b)
c) d)
Proper testing instruments are selected and used in accordance with section 5.2.4 as stated in “Safety Rules Book-Clause 3.3.2” The person performing the test is qualified and authorized based on his qualification & experience, to perform voltage testing as a part of his or her job responsibilities. Appropriate personal protective equipments are used while performing the task. Although voltage testing and diagnostic testing are performed within Prohibited Approach Boundary, it is recognized that these tasks are performed regularly and should be managed by practices, procedures and authorizations in lieu of specific written job plans.
Diagnostic testing and troubleshooting on energized circuits can be performed only when it has been determined that the task cannot be performed with circuits de-energised.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 9 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
5.2.2 ELECTRICAL POWER ISOLATION: 5.2.2.1 Multi Lock System: Multi-lock system is used to prevent injuries that may occur when an equipment is accidentally energized while it’s being worked on by different crafts. Detailed information can be found in “Procedure for Multi-Lock System in KNPC Refineries” (Document Reference: MAAELAC-03-1330). 5.2.3 JOB AND TASK PLANNING: Team Leader Elect.& A/c Maint. shall ensure to have a process for determining mandatory documentation requirements for job plans. If the job cannot be completed as planned or if conditions change or the job is not started within 2 hours after obtaining work permits, work is stopped and re-planned. Site leadership shall effectively communicate job plans to everyone involved with and affected by the work, including operations and emergency response personnel, where appropriate. 5.2.3.1 Standby Person: Team Leader Elect.& A/c Maint., shall have a process for determining the need for standby person. The responsibilities of the standby person shall include: • •
• • •
•
Being aware of the hazards involved in the task Being competent/authorized to switch off the power to the equipment being worked on Being able to initiate safe rescue Being able to initiate the alarm Being trained in the administration of appropriate first aid (e.g., cardiopulmonary resuscitation or treatment of burns) where there is recognised risk of electric shock and/or burns. Preventing personnel from removing covers not in the job plan or crossing the safe work boundary.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 10 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
•
•
Preventing personnel not involved in the task from crossing the safe work boundary Being totally committed and able to perform any of the above duties without interference.
5.2.3.2 Temporary Electrical Power: The purpose is to provide instructions and guidelines for temporary electrical power and lighting circuit wiring connections at all KNPC sites. Further detailed information can be found in “Procedure for Temporary Electrical Power and Lighting Circuit Wiring Connection.” (Document Reference: MAA-ELAC-03-1491) 5.2.3.3 Electrical Isolation: Electrical isolation may be required before starting work on or near electrical equipment to avoid electric shock and other hazards. The extent of isolation required will depend on the nature of work. Requirement of isolation and extent of isolation shall be jointly decided by the issuing authority and executing authority. [Refer to Safe Work Practices on “Work Permit System and Risk Assessment” and “Safety Rules for the Work on Electrical Power System.” (Document Reference: SHE-TSSA-06-2029 & MAA-ELAC-03-0943)] 5.2.3.4 Tag Out: The use of ‘Danger-Do not Operate’ tag (see Appendix-B) with isolation by local switch shall be limited to minor electrical work carried out by Electrical and A/c Maint. on the following equipment: a) Lighting circuits. b) Equipment installed in laboratories. c) Equipment installed in offices. d) Tag out to be used only when isolation switch is in visible range of the person working on electrical equipment. 5.2.4
NO-VOLTAGE TESTING:
Team Leader Elect. & A/c Maint. shall ensure to have standard maintenance manuals, procedures and practices to test for the absence of voltage before touching bare conductors or parts (i.e., Test Before Touch). The procedures and practices shall include Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 11 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
verifying test instruments on a known energised source before and after the test for absence of voltage. Personnel should test every circuit using "live wire detectors” or “High Voltage Stick” etc, and every conductor, every time, to verify the absence of voltage before touching, and appropriate personal protective equipment shall be used until the absence of voltage is verified. While in some cases this may seem to be redundant or repetitive testing, the practice of Test Before Touch is the critical step that minimises risk of contacting an energised conductor due to unexpected and unplanned situations, such as the following: Unexpected energization from failure of equipment insulation or isolation Equipment or circuit labelling errors Wiring errors Drawing or other documentation errors Unintentional breaching of the safe working zone during planned work activity Errors in equipment identification due to physical orientation, symmetry, or similar appearance resulting in incorrect isolation.. Unauthorised re-energization or other failure of the lockout procedure Stored electrical energy e.g. capacitors or capacitance effect of cables. Back feeds from other fixed or temporary supplies such as UPS’s, generators and ATS etc. •
• • • •
•
•
•
•
All personnel performing no-voltage tests shall be trained for no voltage testing in the site. Training and qualifications must be specific for each voltage test instrument. The procedures and practices for voltage testing should include but not be limited to the following (Refer Safety Rules Book-Clause 3.8.1” and Standard Maintenance Manual). • • •
Selection and use of testing instruments. Removal of obsolete instruments from service. Convergence on the make and model of test instruments to simplify training and qualification requirements.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 12 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
•
•
•
•
•
5.2.5
Compliance of test instruments with current local industry and national standards for mechanical integrity, over voltage protection and user safety. Availability of test instruments before removing covers guards or barriers. Availability of voltage sensing devices at the point of use of test instruments. Ensuring that no body part shall pass the plane of enclosure openings before the test instrument. Whenever possible, single-function instrument should be used to reduce the risk of misreading due to scaling, ranging or other errors that can occur with multi-meters as far as possible. PERSONAL PROTECTIVE EQUIPMENT:
The selection, approval, application, provision, storage, use, and maintenance of all electrical personal protective equipment shall be as per Personal Protective Equipment Program document no. SHETSOH-4-1315. 5.2.6
TROUBLE SHOOTING:
Team Leader Elect. & A/c Maint., shall ensure to have Standard Maintenance Manual(SMM) which describes safe work practices for trouble shootings. Site practices will emphasize de-energized troubleshooting techniques and other practices that reduce exposure to energised circuits and conductors as per SMM. 5.2.7
DISMANTLE AND REMOVE / REARRANGE WORK:
The identification, cutting, and removal of electrical raceways and cable often involve a high level of risk in determining that the correct cable is removed. The risks involve exposure of people performing the work to electrical hazards and disruption to operations if a critical energy or control circuit is damaged. Team Leader Elect. & A/c Maint., shall ensure to have a process in place to help ensure that a risk assessment is conducted and
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 13 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
procedures and practices are developed to minimise the risk of injury to people and minimise the disruption of operations. These procedures and practices shall include but not be limited to: Testing for the absence of voltage at the source and destination ends of each cable Positively identifying each cable before it is cut. The preferred method for tracing a cable along its length from a known isolated source is to use a current injection kit and clamp-on meter ( a cable is checked using the clamp-on meter at different locations while a set of different current values are injected). A cable must not be picked up in a tray and traced by moving one’s hands (hand-over-hand) along the length of the cable. Positively identifying a cable at both sides of a barrier (e.g., a wall or duct) for each individual circumstance and having a competent/authorized person approve the procedure and/or practice. A cable must not be traced using a hand-over-hand method as per “Safety Rules Book-Clause 3.7.1”. Deciding on the location where the cable to be cut based on the level of possible risk associated with damaging other cables. The risk of personnel injuries can be minimized when using suitably grounded pneumatic cutters or cable spiking tools along with personal protective equipment. Securing and labelling cable ends that remain exposed during and on completion of the cable removal activity. A record should be kept of any abandoned cables and physical steps should be taken to prevent their inadvertent reconnection/ re-energizing. •
•
•
•
5.2.8
DOCUMENTATION AND EQUIPMENT LABELLING:
Drawings, panel directions and other reference documentations provide critical and reliable information for planning to safely isolate, operate and maintain electrical equipment and systems. Examples of such critical reference documentations include but are not limited to the following: Single line drawings. Schematic diagrams. Maps of underground electrical equipment. Area classification drawings. Panel schedules. • • • • •
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 14 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
•
Electrical system studies (e.g. short circuit, protective device coordination and arc flash hazard analysis studies)
Procedures and practices must be in place to help ensure that: The electrical documentations necessary to identify and isolate electrical hazards are accurate, up-to-date and accessible. Labels and equipment identifications are specified, provided and maintained to provide warnings, cautions and circuit information critical to safe operation and maintenance of electrical equipment and systems, including abandoned-in-place wiring and equipment. Only one labelling convention is used across each site. •
•
•
5.2.9
EXCAVATIONS / PENETRATIONS:
Team Leader Elect.& A/c Maint., shall have procedures and practices for helping ensure that the electrical lines, conduits, and cables in the area of work activity are identified before performing excavations, concrete floor penetrations, and wall penetrations using cable detection, etc. The job shall be carried out by competent person.
5.2.10 CRANES AND MOBILE EQUIPMENT: No specific procedure is required ,since there are no over head electric lines passing in the premises of Refineries. However the employees should ensure that Crane / mobile equipments do not come close to Electrified Security fence etc,.
5.2.11 WATER / STEAM CLEANING: All electrical equipments used in refineries shall be designed, built and approved as per IP55 which are unlikely to be affected by equipment cleaning using water/steam. Portable electric-powered cleaning equipment shall be protected with a residual current device (RCD) or an earth leakage circuit breaker (ELCB) (see Section 5.2.13). Additional care shall be taken to ensure earth continuity, including the fitting of an additional external earthbonding conductor.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 15 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
5.2.12 POWER DISTRIBUTION SWITCHING: Only personnel authorised by Team Leader Elect.& A/c Maint. shall manage and execute power system operations activities. It shall be ensured to develop and implement procedures and practices to eliminate hazards where feasible and minimise risk of personnel injury and disruption of power to operations. In addition to the requirements in this document, the procedures and practices shall address the following: Routine switching of feeders and equipment Control of temporary safety grounds/earths Control of excavating equipment near underground lines and aerial equipment near overhead lines. Switching sequence to minimize the risk of being exposed to arc flash hazards. Techniques to effectively identify and communicate safe work zones in switchgear Training, renewal, and succession planning for key job functions System studies updates (e.g., arc flash hazard analysis, protection co-ordination, and others deemed appropriate by each site). • • •
•
•
• •
5.2.13 MANAGEMENT OF CHANGE – TECHNOLOGY: Team Leader Elect. & A/c Maint., shall ensure to have procedures in place to help ensure that design changes and field modifications in electrical systems are reviewed, approved, documented, and communicated to personnel who may be affected by the changes. 5.2.14 MANAGEMENT OF ELECTRICAL HAZARDS: Following are some of the causes of electrical hazards. i. Faulty or damaged wiring or equipment ii. Loose connections iii. Use of under-rated wiring or poor quality fittings iv. Lack of earthing / grounding / bonding v. Lack of protective safety devices. vi. Use of overrated fuses or jumpers. vii. Working on live equipment. viii. Water seepage or handling with wet body parts. ix. Poor house keeping. Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 16 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
x.
Handling of electrical equipment by incompetent person, lack of awareness and training xi. Lack of safe working procedures and poor communication xii. Failure to use appropriate PPE & tools. xiii. Lack of warning signs. xiv. Lack of proper identification 5.2.14.1 Arc Hazards: If there is a likely hood of arc hazards, Manager Engg & Maint. shall ensure to have procedures and practices to reduce potential exposure to electric arc hazards. He shall have a process to help ensure an arc hazard analysis of site electrical systems is performed and documented to determine the level of arc energy and the consequences of an arcing fault as per IEEE 1584-2002. 5.2.14.2 Arc Hazards and Oil Filled Equipment: Arcing faults in oil-filled electrical equipment (e.g., oil-filled transformers and circuit breakers) have an additional component of hazard and risk. Arcing faults within the enclosure or tank can result in a burn hazard from hot oil being expelled from the unit. This is due to overpressure created by expanding gases from the arc energy. The overpressure can result in either a tank rupture or pressure relief devices operating, and hot oil can be expelled in all directions in the immediate area of the unit. The hot oil can ignite when it exits the unit’s relief device or ruptured tank and contacts oxygen. Burn injuries or fatalities may result from the burning liquid igniting anything with which it comes in contact. For sites with liquid-filled, insulated electric power distribution equipment, Team Leader Elect. & A/c Maint. shall ensure to have a process (i.e., process hazard analysis or another method deemed appropriate by management) for assessing the additional potential hazards of liquid-filled, insulated equipment that is part of the electric power distribution system. 5.2.14.3 Shock Hazard: Team Leader Elect.& A/c Maint., shall ensure to have procedures and practices to assess and manage shock hazards. Proper design, Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 17 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
installation, and maintenance of equipment grounding/earthings and bonding are critical to managing shock hazards. Mandatory requirements for managing the mechanical integrity of grounding/earthings and bonding. Team Leader Elect & A/c Maint. shall ensure to have a procedure for installations that require RCDs. As a minimum, all portable tools and appliances, temporary wirings and extension cords operating at a voltage >24V and are subjected to rough service and/or are routinely plugged and unplugged to an earthed electrical power system must be protected by permanent or portable RCDs or ELCBs. These devices must have a 30 mA maximum current setting. Team Leader Elect.& A/c Maint. shall consider using the following technologies to complement the overall shock protection programme and to minimise risk of shock: Battery-powered tools Reduced-voltage equipment Double-insulated equipment Shrouding and barriers (e.g., to IEC 60529 requirements for IP 20 finger-safe terminals [see Section 2]) Insulated or voltage-rated tools Voltage-rated personal protective equipment (e.g., gloves or hats) Insulated mats on floors Insulated, flexible barriers for exposed equipment parts • • • •
• • • •
Sites with equipments supplied from multiple voltage sources must have procedures to manage shock hazard exposure. The procedures and practices should include but not be limited to the following supplemental elements: Identification of multiple voltage sources inside cabinets Segregated voltages to prevent accidental contact where multiple voltage sources exist in one unit. IEC 60529 requirements for IP 20 (or equivalent) finger-safe terminals to prevent finger contact. Barriers Insulated, voltage-rated tools to minimise the hazards of accidental contact Labelled back feeds, temporary feeds, and dual feeds Identification of the use of common or borrowed neutrals • •
•
• •
• •
Note: The use of common or borrowed neutrals is not recommended. Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 18 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
5.2.14.4 Static Electricity Hazard: Where applicable, Concerned departments/divisions shall ensure to have procedures and practices to assess and manage static electricity hazards, including lightning. Lightning protection is primarily concerned with protection against the hazards of fire & explosion of flammable materials, as well as electrical equipments, caused by lightning Static discharges can be an ignition source, and injuries may result from a person reacting to a static shock. Examples of process operations that may have static electricity hazards include but may not be limited to handling or transporting liquids, solids, or gases in portable containers or piping systems. Certain maintenance activities (e.g., steam cleaning, industrial vacuuming, and sandblasting) can produce static electricity hazards. Guidance on the control of static can be obtained from BS 5958 Code of practice for control of undesirable static electricity . Static electricity hazard can be reduced by minimising the accumulation of charges and draining (earthing) accumulated charges as below. i.
Bonding and earthing between source and receiver of the product handling system (pipe lines, distribution system, spray painting and sand blasting). ii. Minimizing the use of nonconductive materials. In the case where certain processes require the use of nonconductive materials (e.g. hoses, containers, conveyors), antistatic materials shall be used (e.g. antistatic rubber belts, steel-braided hoses) iii. Use of anti-static PPE. iv. Bonding of pneumatic tools and air removers/blower. v. Control of flow rate of static-prone materials. vi. Use of anti-static additive (in Jet fuels). vii. Avoiding splash filling in tanks. viii. Avoiding water contamination of hydrocarbons.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 19 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
5.2.14.5 Explosion Hazard: Guidelines to safely manage explosion hazards that result from arcing faults in electrical equipments in non-hazardous atmospheres can be found under “Arc Hazards” heading in Section 5.2.13. Manager Engg. & Maint., shall ensure to have procedures and practices to assess and manage the risk of explosion hazards associated with electrical equipment. These should include but not be limited to: •
•
•
•
•
•
•
5.3
Provision and maintenance of drawings and documents describing the limits of the hazardous area and its classification. Selection and procurement of electrical equipment appropriate for the area classification. Installation of electrical equipment so that it does not compromise the area classification. Maintenance of the mechanical integrity of the installation, including grounding and bonding, wall penetrations for cabling and electrical control rooms. Methods to exclude other potential ignition sources from entering the area Maintenance of the mechanical integrity and calibration of explosion meters Control and maintenance of safety interlocks
PERSONNEL: 5.3.1 TRAINING AND PERFORMANCE: Team Leader Elect.& A/c Maint. shall ensure personnel are competent/authorized and have received proper training in the following: Recognition and management of electrical hazards they may be exposed to in their jobs. Understanding and using electrical safety procedures and practices. In addition, refresher training to keep knowledge and skills valid and up-to-date must be offered at appropriate intervals and must be documented. First Aid training for electrical personnel is not required since 24 hours coverage is available by Medical Crew •
•
•
•
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 20 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
5.3.2 CONTRACTOR ADMINISTRATION: Team Leader Elect.& A/c Maint. shall ensure that all concerned contractors and their employees have received electrical safety training aligned with site requirements .
5.3.3 INCIDENT INVESTIGATION AND REPORTING: KNPC document on Incident investigation and Reporting Procedures shall be followed for all electrical incidents. 5.3.4 MANAGEMENT OF CHANGE – PERSONNEL: Team Leader Elect & A/c Maint. shall ensure that people in functions deemed critical for sustaining electrical safety programmes have the necessary skills and experience to carry out their jobs. Only authorised personnel must perform work involving electrical hazards 5.3.5 EMERGENCY PLANNING AND RESPONSE: Manager SH&E shall ensure that preparedness for electrical safety emergencies (e.g., rescue and treatment for electric shock, arc flash burns, blast injuries, or fire involving electrical equipment)is adequate by conducting MIPP-mock drills. Preparations for response to electrical emergencies should include but not be limited to: •
• •
• •
•
Providing CPR training to first responders and personnel in highrisk exposure to electric shock. Conducting mock drills of electrical injury emergencies. Marking energy isolation points and developing emergency switching plans. Train appointed people to carryout emergency isolations. Having emergency equipment, including communications equipment, available and accessible. Having procedures established for securing the scene of an electrical incident. The procedure should address the safety of
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 21 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
•
5.4
people in the area as well as the preservation of evidence for the investigation. Having procedures and training on the appropriate use of personal protective equipment.
FACILITIES: 5.4.1 QUALITY ASSURANCE: Team Leader Elect.& A/c Maint. shall ensure to have a program by name SAT(Site Acceptance Tests) quality assurance program to ensure the consistency of the installed electrical equipments with design and specifications and manufacturer’s recommendations. All installations shall meet all applicable national codes and regulations at the time of installation. When required by national codes and regulations, existing installations shall be upgraded to meet current codes and regulations. 5.4.2 PRE START-UP SAFETY REVIEW: Team Leader Elect.& A/c Maint. shall ensure to perform pre start-up safety reviews of all new and modified electrical systems and equipment. The pre start-up safety review team must have the required skills to carry out an effective review. The pre start-up safety review shall confirm that: Permanent circuit identification and isolation information is installed and verified as correct. Accurate documentation needed to plan energy isolation and lockout/tag out is available. Equipment construction and installation are in accordance with design specifications, national regulations, and KNPC Standards. Arc flash hazard assessment, if applicable, is complete. •
•
•
•
5.4.3 MECHANICAL INTEGRITY: Team Leader Elect.& A/c Maint., shall ensure to have procedures and practices to manage the integrity of electrical equipment, including grounding/earthing and bonding conductors; electrical equipment auxiliary facilities; and tools and equipment critical to the
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 22 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
safety and reliability of the electrical equipment in accordance with national regulations and KNPC standards. Examples of auxiliary facilities, equipment, and tools include but may not be limited to the following: • •
• • •
Roofs and other weather protection for electrical equipment Switchgear internal heaters and room space conditioning to prevent moisture contamination of insulating materials. Temporary safety grounds/earths Testing and troubleshooting instruments Insulated sticks used for switching or fuse installation/removal
5.4.4 MANAGEMENT OF SUBTLE CHANGE – FACILITIES: Manager Engg. & Maint. shall ensure to have procedures and practices to manage subtle change that affects exposure to electrical hazards. Examples of subtle change include but may not be limited to the following: •
• • • • •
•
6.0
Change in grade elevation that could alter the depth of underground conductors or elevation of overhead electric lines. Connection of temporary generators Temporary connection of redundant power sources Temporary electrical installations or service to temporary buildings Any change that significantly affects the available fault current Any change in the size, type, or settings of circuit protection devices Abandoned electrical equipment, including raceways, cables, and wiring. Site practices should emphasise the removal of abandoned electrical equipment to control “creep” in increased complexity of site electrical systems.
MANAGEMENT SYSTEM: 6.1
SUPPORT RESOURCES: Manager Engg. & Maint. shall ensure to maintain a list of consulting resources to help resolve issues of regulatory and policy requirements.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 23 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
6.2
MANAGEMENT RECORDS: Records must be retained in compliance with SHEMS Element # 6.
6.3
AUDIT REQUIREMENTS: Team Leader Elect.& A/c Maint. shall ensure to have a safety performance audit programme that assesses compliance of site procedures and practices . These audits must also address local laws, regulations, and situations unique to the site relative to electrical safety.
6.4
PROCEDURE RENEWAL PROCESS: This document must be reviewed and revised as necessary and, at a minimum, not later than three years from the date of the last revision.
6.5
DEVIATION PROCESS: Deviations from this procedure must be authorised by the Deputy Managing Director - Refinery after consultation with the KNPC SH&E Department. Deviations must be documented, and documentation must include the relevant facts supporting the deviation decision. Deviation authorisation must be renewed periodically and no less frequently than every three years.
6.6
TRAINING AND COMMUNICATIONS REQUIREMENTS: Safety Department, shall ensure to have electrical safety training at sites in accordance with established procedures (see section 5.3.1).
6.7
CONTACT: The contact for this document is the KNPC SH&E Dept
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 24 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
APPENDIX – A 4. (B) Electrical Isolation Not Required ( or N/A ) Use single lock
Use “Do not operate tag” Use Multi lock
(i) All Electrical circuits / equipment have been isolated by: Emp. Name Emp.No. Designation
(ii) Multi Lock System Name / Emp. No. / Signature Shift Electrical Maint. Mechanical Maint.
Signature
Others
Tel. Ext.
Date
Time
5. Authorization /Renewal (It is safe to proceed with this job) Date/ Shift
Time Issuer From
Name / Emp.No. /Signature Executor Contractor Field Oper.
To
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 25 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
6. Permit Closure (A) Work
completed
Site handed over in a safe condition
stopped
Housekeeping done. Yes
Emp. No.
Yes
No
No
Multilock removed
Executor name
will continue on …………..
Yes
Designation
No
Not applicable
Signature
Time
Date
Remarks:……………………………………………………………..…………………………… …………………………………………………………………………………………………….. (B) Agreed to above. Site was checked and found safe.
Yes
No
Field Operator signature / Emp no………………………………………………………………..
Issuer name
Emp. No.
Designation
Signature
Time
Date
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 26 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
APPENDIX – B “ELECTRICAL ISOLATION TAG”
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 27 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
ANNEXURE - I GUIDELINES FOR AREA CLASSIFICATIONS These guidelines primarily meant for analysing and classifying the environment where explosive vapor/gas atmosphere may occur so as to facilitate the proper selection, installation and use of electrical/instrument apparatus. 1.0
DEFINITIONS: 1.1
HAZARDOUS LOCATIONS: Hazardous locations are those locations, areas, or spaces where fire or explosion hazards may exist due to flammable gases or vapors, flammable liquids, combustible dust, or ignitable fibre or flyings.
1.2
EXPLOSIVE ATMOSPHERE: An explosive atmosphere means a mixture with air, under atmospheric conditions, of flammable substances in the form of gases, vapours, mists or dust in which , after ignition has occurred, combustion spread to the entire mixture.
1.3
FLAMMABLE ATMOSPHERE: A flammable atmosphere is defined as having sufficient concentration of flammable gas, vapour, mist or combustible dust in air under atmospheric conditions capable of being ignited.
1.4
FLASH POINT: The flash point of a liquid is the minimum temperature at which the liquid gives off vapor in sufficient concentration to form ignitable mixture with air near the surface of the liquid within the vessel.
1.5
HAZRDOUS VS. CLASSIFIED LOCATIONS: Hazardous locations are described as classified locations or classified area because they have been classified.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 28 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
2.0
AREA CLASSIFICATION: Use of area classification system helps in
Identifying extent of areas where explosive atmosphere may occur under normal and expected conditions.
Selecting electrical apparatus / instruments for such area.
Locating other equipment like heaters, boilers etc
2.1
CLASSES: In this system, areas are classified and grouped according to the flammable / combustible materials, which may be present. Class – I
Locations are those in which flammable gases or
vapours are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures. Class – II
Locations are those that are hazardous because of the
presence of combustible dust. Class – III 2.2
Locations deal with combustible fibres.
GROUPS: Groups exist to permit classification of locations depending on the properties of flammable vapours, liquids or gases and to permit testing and approval of equipment for such locations. Class I hazardous locations are divided into groups in such a way that
each
group
contains
materials
of
similar
explosion
characteristics.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 29 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
GROUP – A:
Atmosphere containing acetylene
GROUP – B:
Atmosphere containing hydrogen, or gases or vapours of equivalent hazard such as manufactured gas.
GROUP – C:
Atmosphere containing ethyl ether vapours, ethylene or cyclo propane.
GROUP – D:
Atmosphere containing gasoline, hexane, naphtha, benzene, butane, propane, alcohol, acetone, benzol, lacquer solvent vapour or natural gas. Class II locations are divided into three groups identifying the specific materials involved.
GROUP – E:
Atmosphere containing metal dusts, including aluminium, magnesium and their commercial alloys and other combustible dusts whose particle size, abrasiveness and conductivity present similar hazards in the use of electrical equipment.
GROUP – F:
Atmosphere containing combustible carbonaceous dusts, including carbon black, charcoal, coal, or coke dusts that have more than 8% total entrapped volatiles or dusts that have been sensitized by other materials so that they present an explosion hazard
GROUP – G:
Atmosphere containing combustible dusts not included in Groups E or F, including flour, grain, wood, plastic and chemicals.
Class III locations groups are not applicable in KNPC
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 30 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
2.3
DIVISIONS: Having decided that a location should
be classified and having
designated the gas or vapour as group A, B, C or D, the next step is to designate the location as per Division. DIVISION 1 - Class I, Division 1 hazardous locations are defined (as per NEC code Article 500) as follows: 1. Those locations in which ignitable concentrations of flammable gases or vapours can exist under normal operating conditions. 2. Those locations in which ignitable concentrations of such gases or vapours may exist frequently because of repair or maintenance operations or because of leakage. 3. Those locations in which break down or faulty operations of equipment or processes might release ignitable concentrations of flammable gases or vapours and might also cause simultaneous failure of electric equipment. DIVISION 2 – Class I Division 2 Locations are as follows: 1. Those locations in which volatile flammable liquids or flammable gases are handled, processed or used, but in which the liquids, vapours and gases will normally be confined within closed containers or closed systems from which they can escape only in case of accidental rupture or break down of such containers or system or in case abnormal operation of equipment. 2. Those locations in which ignitable concentrations of gases or vapours are normally prevented by positive mechanical ventilation
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 31 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
and which might become hazardous through failure or abnormal operation of the ventilating equipment. 3. Those locations which are adjacent to a class I, Division 1 locations and to which the ignitable concentrations of gases or vapours
might
occasionally
be
communicated,
unless
communication is prevented by adequate positive ventilation from the source of clean air
and effective safe guards against
ventilation failure are provided.
2.4
ZONES: Zone 0 - As a location in which ignitable concentrations of gases or vapours are present either (1) continuously or (2) for long period of time. Zone 1 – Zone 1 locations are defined as follows: 1. Those locations in which ignitable concentrations of flammable gases or vapours are likely to exist under normal operating conditions. 2. Those locations in which ignitable concentrations may exist frequently because of repair or maintenance operation or because of leakage. 3. Those locations in which equipment is operated or processes carried on, of such nature that equipment break down or faulty
operations
could
result
in
release
of
ignitable
concentrations and also cause simultaneously failure of electrical equipment in a mode to cause the electrical equipment to become a source of ignition. Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 32 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
4. Those locations adjacent to a Zone 0 location from which ignitable concentrations could be communicated, unless communication is prevented by adequate positive pressure ventilation from a source of clean air and effective safe guards against ventilation failure are provided. Zone 2 - Those locations in which ignitable concentrations of gases or vapours are not likely to occur in normal operations and if they do occur , they will exist only for short period of time. Zone 20 - A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is present continuously, or for long periods or frequently. Zone 21 - A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally. Zone 22 - A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation but if it does occur, will persist for a short period only.
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 33 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
3.0
RELATIONSHIP BETWEEN DIVISION AND ZONE: There is no technical equivalent relationship between division and zone categorizations. However the following table provide a rough comparison.
Class I Area Classification Comparison Division 1:
Zone 0:
Where ignitable concentrations of Where flammable gases, or vapours can
ignitable
concentrations
of
flammable gases or vapours are present
exist all of the time or some of the continuously or for longer periods of time time
under
normal
operating under normal operating conditions.
conditions.
Zone 1: Where
ignitable
concentrations
of
flammable gases or vapours are likely to exist under normal conditions.
Division 2:
Zone 2:
Where ignitable concentrations of Where
ignitable
concentrations
of
flammable gases, or vapours are
flammable gases, or vapours are not
not likely to exist under normal
likely to exist under normal operating
operating conditions.
conditions
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 34 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
4.0
RELATIONSHIP AMONG CLASS, DIVISION & ZONE: 4.1
Class I, Division 1: Class I, Division 1 location is a location:
In which ignitable concentrations of flammable gases or vapours can exist under normal operating conditions or
In which ignitable concentrations of such gases or vapours may exist frequently because of repair or maintenance operations or because of leakage or
In which breakdown or faulty operation of equipment or processes might release ignitable concentrations of flammable gases or vapours and might also cause simultaneous failure of electrical equipment in such a way as to directly cause the electrical equipment to become a source of ignition.
4.2
Class I, Division 2: Class I, Division 2 location is a location:
In which volatile flammable liquids or flammable gases are handled, processed, or used but in which the liquids, vapours, or gases will normally be confined within closed containers or closed systems from which they can escape only in case of accidental rupture or breakdown of such containers or systems or in case of abnormal operation of the equipment or
In which ignitable concentrations of gases or vapours are normally prevented by positive mechanical ventilation and which might become hazardous through failure or abnormal operation of the ventilating equipment or
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 35 of 37
PRINTED COPY NOT CONTROLLED
KUWAIT NATIONAL PETROLEUM COMPANY
That is adjacent to a class I, Division 1 location, and to which ignitable
concentrations
of
gases
or
vapours
might
occasionally be communicated unless communication is prevented by adequate positive –pressure ventilation from a source of clean air and effective safeguards against ventilation failure are provided. 4.3
Class I, Zone 0: Class I, Zone 0 location is a location in which
Ignitable concentrations of flammable gases or vapours are present continuously or
Ignitable concentrations of flammable gases or vapours are present for long periods of time.
4.4
Class I, Zone 1: Class I, Zone 1 location is a location:
In which ignitable concentrations of flammable gases or vapours are likely to exist under normal operating conditions or
In which ignitable concentrations of flammable gases or vapours
may
exist
frequently
because
of
repair
or
maintenance operations or because of leakage or
In which equipment is operated or processes are carried on of such a nature that equipment break down or faulty operations could result in release of ignitable concentrations of flammable gases or vapours and also cause simultaneous failure of electrical equipment in a mode to cause the electrical equipment to become a source of ignition or
Document no: SHE-TSSA-06-2014 Rev.- 01 Title: Safe Work Practices: “Electrical Safety” Page 36 of 37
View more...
Comments