Attachment 2c - SHE and Eng Standards.pdf

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Safety, Health, and Environmental Standard

Title: High-Voltage Electrical Work

Standard No.: B4

Effective Date: 06/15/2022

Releasability: There are no releasability restrictions on this publication.

The provisions and requirements of this standard are mandatory for use by all personnel engaged in work tasks necessary to fulfill the AEDC mission. Please contact your safety, industrial health and/or environmental representative for clarification or questions regarding this standard.

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FA9101-25-R-B001

Attachment 2c

Safety, Health and Environmental Standard B4

Record of Review/Revision

Date/POC Description 09/22/21

Wolfe Periodic Review – administrative changes. Renumbered section 2 so paragraphs were in subsequent order. Updated references and annexes as needed.

11/13/18 Russell/Tate

Updated applicability to focus on base operating contractors. Removed references to Automatic External Defibrillators (AED’s). Updated references to NFPA standards.

03/24/15 Northcott; Tate

Updated to align with the 2015 NFPA 70E Standard for Electrical Safety in the Workplace.

07/16/14 Tate; Northcott

Administrative update to incorporate current arc flash labels.

02/07/13 R. Tate

T. Northcott

Three-year review: Clarified a number of sections and restructured to align with SHE Standard B4 Low-Voltage Electrical Safety-Related Work Practices where appropriate. Added limited approach distances for direct current; modified EEWP approval block (Annex A); added nomenclature to Annex D throughout. Deleted obsolete annexes and renumbered remaining annexes. Added attachments for Electrical Operational and Electrical Maintenance work flow charts. Added NFAC Supplement. [03/11/2013: Incorporated Base Operating Contractor Process Council administrative changes; 03/21/2013: Incorporated Base Operating Contractor Executive Management Steering Committee Changes.]

08/29/11 R.Eichel T. Wiley

T. Northcott

Updated throughout for consistency of terminology with SHE Standard B6 Low Voltage Electrical Work; provided separate Energized Electrical Work Permit for high voltage operations. Clarified when a hold order is required. Defined Power System Dispatcher, Hold Order Issuer (Plant) and Assignee. Added requirement for Directors to appoint hold order issuers in writing annually and to forward list to Electrical Operations. Combined definition of supervisor and craft supervisor. Deleted references to emergency services. Updated High Voltage Hold Order Annex with Plant hold order issuer information; added examples and noted ability of multiple work groups to work under same hold order.

03/25/09 S. Bryan and

ESS

Revised to incorporate September 2008 NFPA 70E requirements throughout. These requirements became available in December 2008. Revisions made in coordination with the Electrical Systems Subcommittee (ESS).

11/05/07 S. Bryan

Annual review: Minor revision to clarify NFPA 70E requirements for arc flash clothing for work on Hazard Risk Class 0 – long-sleeved shirts are required.

11/09/06 T. Lavelle

Major revision: Read entire standard

1/6/05 R. Jones

General revision, reorganization and incorporation of site comments.

03/05/04 G. Neal

Clarified PPE requirements; reformatted Annexes and tables.

01/15/04 Initial Safety Standard Issued.

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Effective Std. No.

06/15/2022 B04

Safety, Health, and Environmental Standard

HIGH-VOLTAGE ELECTRICAL WORK

1.0 INTRODUCTION/SCOPE/APPLICABILITY

1.1 Introduction – This standard outlines the hazards involved, safety equipment required, safety precautions to be observed, and operating procedure requirements when working with high voltage electricity, i.e., any voltage greater than 600 volts. Any time a high voltage supply is locked out to provide personnel protection a hold order shall be required.

EXCEPTION: Linemen working under a caution order are exempt from the hold order requirement.

1.2 Scope – This standard applies in all situations where exposure to energized or potentially energized electrical equipment is possible due to the nature of the work to be performed. Following this standard will help ensure that electrical work is performed under the safest conditions possible.

This standard addresses safety of workers whose job responsibilities entail interaction with electrical equipment and systems with potential exposure to energized electrical equipment and circuit parts. Concepts in this standard are often adapted to other workers whose exposure to electrical hazards is unintentional or not recognized as part of their job responsibilities. The highest risk for injury from electrical hazards for other workers involve unintentional contact with overhead power lines and electric shock from machines, tools, and appliances.

1.3 Applicability – This standard applies to all base operating contractor employees and subcontractors engaged in operations, maintenance, or construction at AEDC.

2.0 BASIC HAZARDS/HUMAN FACTORS

2.1 Shock Hazard – A dangerous condition associated with the possible release of energy caused by contact or approach to energized electrical conductors or circuit parts. Electric shock is the most common hazard to be encountered in electrical operations. This is caused when a person comes in contact with an energized part, and electrical current travels through the body. Minor shock may cause tingling or discomfort. A serious shock may cause extreme pain, burns, and/or death. Although the shock may not be severe enough to stop breathing, it may cause a fall or other accident. If a worker sustains a severe shock that does stop the heart and/or breathing, cardio-pulmonary resuscitation (CPR) should be administered by a properly trained individual immediately and medical aid should be summoned.

CAUTION: Workers shall exercise extreme caution to avoid contact with a “hot” line or bus bar.

2.2 Arc Flash Hazard – A dangerous condition associated with the release of energy caused by an electric arc. This flash can damage a person’s eyes, cause burns up to 3rd degree, and/or death. This hazard exists when energized electrical conductors or circuit parts are exposed or within guarded or enclosed equipment, provided a person is interacting with the equipment in such a manner that could cause an electric arc.

Arcing can also cause overheating to the extent molten metal may be expelled which may result in the worker being burned. Vaporized metal and ionized gases, as well as metallic fragments, may be violently thrust into the zone occupied by the worker, necessitating use of arc-rated (AR) personal protective equipment (PPE).

2.3 Arc blast – An explosive force caused by the rapid expansion of super-heated air and metal vaporized during an electric arc. Arc blasts can damage a person’s hearing or cause other internal injuries. Shrapnel from the blast may pierce the skin. Blasts from higher energies may cause death.

2.4 Fire – Improper wiring, circuit overloading, and defective tools or equipment can cause sparking, or overheat wires. This could cause a fire and damage property or injure personnel.

3.0 DEFINITIONS

Arc Flash Protection Boundary – When an arc flash hazard exists, an approach limit at a distance from a prospective arc source within which a person could receive a second degree burn if an electrical arc flash were to occur.

Barricade – Physical obstruction such as tapes, cones, or wood or metal structures intended to provide a warning and to limit access to a hazardous area.

Barrier – Physical obstruction which is intended to prevent contact with energized lines or equipment or to prevent unauthorized access to a work area.

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Base Operating Contractor – A long-term contractor directly accountable to the Air Force for the AEDC mission; term used to identify the AEDC Operation, Maintenance, Information Management and Support Contractor.

Bond – The electrical interconnection of conductive parts designed to maintain a common electrical potential.

Bus – A conductor or a group of conductors that serve as a common connection for two or more circuits.

Cable – A conductor with insulation (single-conductor cable), or a combination of conductors insulated from one another (multiple-conductor cable).

Cardiopulmonary Resuscitation (CPR) – An emergency medical procedure, which includes opening and maintaining an airway, providing ventilation through rescue breathing, and providing artificial circulation through the use of external cardiac compression.

Caution Order – Formal procedure for keeping a high voltage circuit or line from being automatically re-energized.

Circuit – A conductor or system of conductors through which an electric current is intended to flow.

Clearance (between objects) – Clear distance between two objects measured surface to surface.

Competent Person – A individual capable of identifying existing or predictable hazards in the surroundings of working conditions which are hazardous or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them.

Conductor – A material, usually in the form of a wire, cable, or bus bar, used for carrying an electric current.

Craft Supervisor – Supervisor responsible for the safety of work crews performing maintenance or servicing of equipment or systems; this may also be the person normally designated by management to implement high voltage hold order procedures in their area of responsibility.

Current-Carrying Part – A conducting part intended to be connected in an electric circuit to a source of voltage. Non-current-carrying parts are those parts which are not intended to be so connected.

De-energized – Free from any electrical connection to a source of potential difference and from electrical charge: not having a potential different from earth. De-energized alone does not constitute an electrically safe work condition.

Diagnostic Work – A category of work that involves the taking readings or measurements of electrical equipment, with approved test equipment which does not require making any physical change to the equipment. In most cases, diagnostic work requires shock PPE and/or arc flash PPE along with other required industrial PPE.

Electric Equipment – A general term including material, fittings, devices, appliances, fixtures, apparatus, and the like used as part of or in connection with an electrical installation.

Electrical Equipment – Wiring, circuits, switches, switchgear, fuses, breakers, distribution systems, and any other equipment or systems capable of containing electrical energy.

Electrical Standby Person – An employee trained in energized electrical procedures, emergency rescue techniques for electric shock victims, cardiopulmonary resuscitation (CPR), first aid, and confined space procedures, as warranted by the job situation.

Electrical Supply Lines – Outdoor overhead conductors supported on a pole or other structure and used to transmit electric energy.

Electrically Safe Work Condition – A state in which the conductors, circuits, and equipment to be worked on has been disconnected or isolated from energized parts, locked/tagged in accordance with established lockout/tagout practices [as detailed in AEDC SHE Standard B2 - Lockout/Tagout (LOTO)], and are tested to ensure the absence of voltage.

(Flowcharts for achieving electrical safe work conditions for Electrical Maintenance and Electrical Operations are provided in Attachments 1 and 2.)

Energized – Electrically connected to, or is, a source of voltage. Any electrical circuit or circuit part that has not been disconnected, LOTO, absence of voltage properly verified, and grounded shall be considered energized.

Energized Electrical Work Permit (EEWP) – A permit which authorizes work to be performed by a qualified electrical person within the Restricted Approach Boundary or Arc Flash Boundary of an energized circuit. The purpose of the permit is to ensure the increased risks posed by this work receive adequate consideration (Permit Form Annex A of this Document).

Energy Source – Any electrical, mechanical, hydraulic, pneumatic, chemical, nuclear, thermal, or other energy source that could cause injury to personnel.

Exposed (as applied to live parts) – Capable of being inadvertently touched or approached nearer than a safe distance by a person. It is applied to parts that are not suitably guarded, isolated or insulated.

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Exposure – Where hazards are present or could be created that might result in harm to personnel, equipment or the environment if not properly controlled.

Ground – A conducting connection, whether intentional or accidental, between an electric circuit or equipment and the earth, or to some conducting body that serves in place of the earth.

Grounded – Connected to earth or to some conducting body that serves in place of the earth.

Guarded – Covered, fenced, enclosed, or otherwise protected, by means of suitable covers or casings, barrier rails or screens, mats, or platforms, designed to minimize the possibility, under normal conditions, of dangerous approach or accidental contact by persons or objects.

NOTE: Wires which are insulated, but not otherwise protected, are not considered to be guarded.

Hazardous Work – Work involving exposure to energized electrical parts.

High-Voltage Hold Order – A formal procedure for isolating high-voltage equipment from any source of electric potential. See Annex B.

Hold Order Assignee – A qualified person, trained in the hold order process and who has been designated by management to be issued hold orders. This person is responsible for determining that all necessary safeguards have been taken before permitting maintenance work or inspection of electrical equipment or circuits covered by the hold order.

Hold Order Issuer, Plant – A person who is technically qualified, through experience and or training, to determine necessary points of protection on a system for a specified configuration and who is designated in writing by management to perform the duties.

Insulated – Separated from other conducting surfaces by a dielectric (including air space) offering a high resistance to the passage of current.

Insulation – That which is relied upon to insulate the conductor from other conductors or conducting parts or from ground.

Job Safety Analysis (JSA) – (Also known as a safe plan of action or similar name.) A document prepared to help workers and management review hazards and safety precautions required for each job. (See SHE Standard A10 - Job Safety Analysis for details.)

Job Safety Review (JSR) – A streamlined safety analysis technique for routine jobs meeting the following criteria:

1. The job is routine (At least one assigned person has experience on the job)

2. The job must be able to be completed in three days or less, and a new JSR must be initiated each day.

3. Three persons or less are assigned to the job.

(See SHE Standard A10 - Job Safety Analysis for details.)

Limited Approach Boundary – An approach limit at a distance from an exposed energized electrical conductor or circuit part within which a shock hazard exists. Non-electrically qualified personnel may not cross this boundary unless escorted by a qualified electrical person.

Line Truck – A specialty vehicle designed for electrical supply line work, that includes a boom with a power take off for an auger or set of jaws for setting power poles.

Minimum Approach Distance – The closest distance a qualified employee is permitted to approach either an energized or a grounded object, as applicable for the work method being used.

Outside Contractor/Subcontractor - An organization employed by a contractor or the Air Force to do construction, maintenance, repair or other work at AEDC. There is no employment relationship, control or supervision of the subcontractor's employees by AEDC contractors. Also referred to as the construction contractor.

Personal Protective Equipment (PPE) – Equipment such as voltage-rated rubber gloves, hard hats, face shields, protective arc-flash clothing, hoods, etc. used to protect the worker from electrical shock and arc-flash hazards. (See SHE Standard F2 - Personal Protective Equipment for additional information.)

Potentially Energized – Electrical equipment or circuits capable of containing electrical energy that has not been locked out, tagged out, and verified as de-energized by proper testing methods.

Power System Dispatcher – An electrically qualified person who, in accordance with the power agreement between AEDC and TVA, has the responsibility for the safe operation of the electrical power distribution system at AEDC.

This person controls loads on feeders within specified limitations, directs all switching operations when it becomes necessary to make configuration changes to the power distribution system, keeps all required logs and forms for permanent retention, provides clearances and issues and tracks all Hold Orders Numbers. He directs all activities of the Power Switchboard Operator for safe and efficient operation of the high voltage distribution equipment.

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Qualified Electrical Person – Persons who, by training and demonstration, possess the skills and knowledge to (1) distinguish exposed live parts from other parts of electrical equipment, (2) determine the nominal voltage of exposed live parts, (3) maintain minimum clearance distances corresponding to the voltages to which that person will be exposed, and (4) have the training required to identify and avoid the hazards involved. A qualified electrical person may be an electrician, electrical technician, electrical engineer, or others, depending on their function and training, and may only be qualified with respect to certain aspects of electrical work. (See Section 5.)

Qualified Industrial Person – Employees trained in basic industrial safety including but not limited to:

• Lockout/Tagout • Confined Space • Job Safety Analysis • Personal Protective Equipment

• Electrical Safety • Fall Protection • Master Work Permit

Reasonable Effort to De-Energize – This is a subjective judgment by supervision, the worker, and electrical/plant operations which produces a risk assessment that considers personnel safety, impact of switching effort hazards, mortality risk of equipment, and the impact of the outage.

Repair Work- A category of work that involves any physical alteration of electrical equipment (such as making or tightening connections, removing or replacing components, etc.).

Restricted Approach Boundary – An approach limit at a distance from an exposed live part, within which there is an increased risk of shock due to electrical arc over combined with inadvertent movement, for personnel working in close proximity to the live part. An EEWP is required to cross this boundary; see 4.1.1.6 for exceptions.

Rubber Insulating Blankets - Molded sheets of insulating rubber or synthetic elastomer, usually square or rectangular, designed to cover energized electrical equipment to prevent direct accidental contact by electrical workers. (See ANSI/ASTM F479 and D1048.)

Switch – A device for opening and closing or for changing the connection of a circuit. In this standard, a switch is understood to be manually operable, unless otherwise stated.

Task Qualified Electrical Person – Persons who have been trained to safely perform only specific electrical task(s) for which they have received the appropriate level of electrical training, safety training, and have appropriate PPE available.

Voltage – The potential difference between any two conductors or between a conductor and ground/earth.

Voltage, Nominal – A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (600, 2,400, 6,900, 13,800, etc.). The actual voltage at which a circuit operates can vary from the nominal within a range that permits satisfactory operation of equipment.

Work Clearance – Authorization to perform specified work or permission to enter a restricted area.

Working on Energized Equipment – Intentionally crossing the prohibited approach boundary of energized electrical conductors or circuit parts with the hands, feet, or other body parts, with tools, probes, or test equipment, regardless of the PPE a person is wearing. This includes diagnostic and repair work while the equipment is energized. (See energized definition.)

4.0 REQUIREMENTS/RESPONSIBILITIES

Flowcharts for Electrical Maintenance and Electrical Operations are provided in Attachments 1 and 2.

4.1 REQUIREMENTS

4.1.1 Electrical Safe Work Practices

4.1.1.1 Systems 50 Volts or More: All systems of 50 volts or more shall be considered energized until an electrically safe work condition is established using appropriately rated test equipment and the correct types and level of PPE. Proper PPE, including arc flash protection, shall be used in accordance with equipment labeling (e.g.

Annex B). If no label is present refer to Annex C and Annex D while equipment is considered energized.

4.1.1.2 Every reasonable effort shall be made to de-energize and control electrical equipment operating at 50 volts and above per the SHE Standard B02 – Lockout/tagout prior to performing any repair/non-diagnostic work on them. Energized work shall be permitted only where it can be demonstrated that the task to be performed is infeasible in a de-energized state due to equipment design or operational limitations.

4.1.1.3 Electrical circuits shall be confirmed de-energized prior to performing Repair Work on them unless an EEWP has been completed. All circuits shall be considered energized until proven to be de-energized using appropriate test equipment (Section 4.1.2) and grounded if necessary (Section 4.1.3).

4.1.1.4 Equipment with Arc Flash Incident Energies above 40 cal/cm2 shall be de-energized before any work or local alteration (e. g., breaker operation or racking) may be performed.

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4.1.1.5 Energized electrical equipment with Arc Flash Incident Energies of 40 cal/cm² or less can be worked/operated only when approval is granted with proper documentation (JSA and EEWP, when required) and all required PPE is worn.

4.1.1.5.1 The correct types and level of PPE is mandatory when performing either repair-type or diagnostic-type work on energized electrical equipment or locally altering the configuration/position of energized electrical equipment, e.g. operating breakers, switches, disconnects; racking breakers, etc. If equipment is not labeled in accordance with Annex C, refer to Annex D, and Annex E or NFPA 70E 2021 Edition.

4.1.1.5.2 Energized conductors/components may be covered and or guarded by blankets, mats, or other non-conductive materials, to protect from accidental contact by the qualified worker when within the Limited Approach Boundary. If the covered/guarded conductors/components can no longer be inadvertently contacted, then the shock hazard and arc flash hazard associated with those conductors/components no longer exist.

4.1.1.6 Energized Electrical Work Permit (EEWP): The EEWP is required when working within the restricted approach boundary or the arc flash boundary of exposed energized electrical conductors or circuit parts that are not placed in an electrically safe work condition.

NOTE: The purpose of the EEWP is to ensure that the increased risks posed by this work receive adequate consideration to ensure that it is infeasible to perform the task with the circuit de-energized (Permit Form Annex A of this document).

4.1.1.6.1 An approved EEWP shall be required before any repair-type work is performed within the prohibited approach boundary of energized electrical equipment operating at greater than 50V AC/DC nominal.

Approvers of EEWP will be designated in writing.

4.1.1.6.2 The EEWP shall not be approved when the Arc Flash Incident is greater than 40 cal/cm².

4.1.1.6.3 The following routine operations do not require an approved EEWP, but does require Manager or Supervisor approval, which is indicated by signing the JSA/JSR or equivalent. Craft cannot provide this approval.

4.1.1.6.3.1 Diagnostic testing, de-energizing or re-energizing an electrical system

4.1.1.6.3.2 Switching, operating disconnects, racking breakers

4.1.1.6.3.3 Operating electrical circuit testing or diagnostic equipment.

4.1.1.6.3.4 Re-lamping by personnel other than a qualified electrical person; no approval is required for a qualified electrical person.

4.1.1.6.3.5 Removal/insertion of a DC Fuse Block rated less than 151VDC nominal.

4.1.1.7 Only a qualified electrical person shall be permitted to work on energized electrical equipment or within the Restricted Approach Boundary of energized circuits or circuit parts.

4.1.1.7.1 Only a qualified electrical person shall energize or de-energize any disconnect over 50 volts where the operation could directly or potentially expose personnel to energized electrical circuits. Personnel may be task qualified to safely operate electrical equipment rated over 50 volts provided they are equipped with the required Arc Flash PPE and trained to identify and avoid the hazards involved with the task.

4.1.1.7.2 A minimum of two qualified electrical persons shall be assigned to any work where the potential exists for direct contact with energized circuits greater than 300 volts nominal or when there is an elevated potential for arc flash such as racking a breaker off of an energized bus. As a minimum, the second qualified electrical person shall be dressed in the same required PPE as the qualified electrical person performing the task.

4.1.1.8 A JSA/JSR or equivalent shall be completed for all electrical work, energized or de-energized.

4.1.1.9 The approach boundaries to live (energized) parts for shock protection are tabulated below. Qualified electrical persons shall provide boundaries to prevent unqualified personnel from getting any closer to exposed energized parts than the Limited Approach Boundary as shown below:

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Nominal Voltage

Limited Approach Boundary Restricted Approach

Boundary Exposed Movable Conductor

Exposed Fixed Circuit Part

600 to 750 10 ft. 0 in. 3 ft. 6 in. 1 ft. 0 in.

751 to 15kV 10 ft. 0 in. 5 ft. 0 in. 2 ft. 2 in.

15.1kV to 36kV 10 ft. 0 in. 6 ft. 0 in. 2 ft. 7 in.

36.1kV to 46kV 10 ft. 0 in. 8 ft. 0 in. 2 ft. 9 in.

46.1kV to 72.5kV 10 ft. 0 in. 8 ft. 0 in. 3 ft. 3 in.

72.6kV to 121kV 10 ft. 8 in. 8 ft. 0 in. 3 ft. 4 in.

138kV to 145kV 11 ft. 0 in. 10 ft. 0 in. 3 ft. 10 in.

161kV to 169kV 11 ft. 8 in. 11 ft. 8 in. 4 ft. 3 in.

Nominal Potential Difference System

Voltage

Limited Approach Boundary Restricted Approach Boundary

Exposed Movable Conductor

Exposed Fixed Circuit Part

Less than 100 Not specified Not specified Not specified 100 to 300 10 ft. 0 in. 3 ft. 6 in. Avoid contact 301 to 1kV 10 ft. 0 in. 3 ft. 6 in. 1 ft. 0 in.

1.1 to 5kV 10 ft. 0 in. 5 ft. 0 in. 1 ft. 5 in.

5 kV to 15 kV 10 ft. 0 in. 5 ft. 0 in. 2 ft. 2 in.

15.1 kV to 45 kV 10 ft. 0 in. 8 ft. 0 in. 2 ft. 9 in.

45.1 kV to 75 kV 10 ft. 0 in. 8 ft. 0 in. 3 ft. 2 in.

75.1 kV to 150 kV 10 ft. 8 in. 10 ft. 0 in. 4 ft. 0 in.

150.1 kV to 250 kV 11 ft. 8 in. 11 ft. 8 in 5 ft. 3 in.

250.1 kV to 500 kV 20 ft 0 in. 20 ft 0 in. 11 ft. 6 in.

500.1 kV to 800 kV 26 ft. 0 in. . 26 ft. 0 in. 16 ft. 5 in.

NOTE: “Exposed movable conductor” describes a condition in which the distance between the conductor and a person is not under the control of the person. The term is normally applied to overhead line conductors supported by poles.

4.1.1.9.1 To cross the restricted approach boundary (possible shock from arc over), the qualified person shall:

(a) Have specified training to work on exposed live parts.

(b) Have a completed and approved JSA/JSR or equivalent and EEWP when required.

(c) Use PPE suitable for working near exposed live parts and rated for the voltage and energy level involved as described in Section 4.1.15.

(d) Be certain that no part of the body enters the prohibited space.

(e) Minimize the risk from unintended movement, by keeping as much of the body as possible out of the restricted space; body parts in the restricted space must be protected.

(f) Employees shall use insulated tools or handling equipment, or both, when working inside the restricted approach boundary of exposed energized electrical conductors or circuit parts. Annex C provides further information for tasks that require insulated and insulating hand tools.

4.1.1.9.2 Limited Approach Boundary:

(a) Boundary is to be set up by the qualified electrical person. The type of boundary used will depend on the area. In high traffic areas, physical barriers, like stanchions or red danger tape may be used. For remote areas, visually monitoring the area may be appropriate. The distance of the barrier from the exposed conductor will be the equal to or greater than the limited approach boundary or the arc flash hazard boundary, whichever is greater. For more information, please see AEDC SHE Standard B3 - Control of Hazardous Areas.

(b) Have a completed/approved JSA/JSR or equivalent.

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(c) May only be crossed by non-electrical personnel when escorted by a qualified electrical person familiar with the current work.

(d) Walls or other physical barriers within the boundary, which provide sufficient protection, will suffice for the barrier, provided entrance is limited.

4.1.1.9.3 Arc Flash Protection Boundary: The distance for the flash hazard boundary will be found on the equipment’s arc flash warning decal (see Annex B). For low-voltage equipment without a decal, the arc flash protection boundary shall be in accordance with the value found in Annex C according to the appropriate equipment type and task. Whenever any part of a person’s body or head is within the arc/flash protection boundary, the person must:

4.1.1.9.3.1 Use appropriate PPE and protective equipment in accordance with the Arc Flash Label attached to the equipment or as specified in Annex D of this standard.

4.1.1.9.3.2 Ensure all PPE is in good condition, is locally inspected prior to use, and has been externally inspected within the required interval, if required.

4.1.1.9.3.3 Have a completed and approved JSA/JSR or equivalent and EEWP when required.

4.1.1.10 Conductive articles of jewelry and clothing (such as watchbands, bracelets, rings, key chains, necklaces, metallized aprons, cloth with conductive thread, metal headgear, or metal framed glasses) shall not be worn when working within the Restricted Approach Boundary of energized or potentially energized circuits or equipment. Qualified Electrical Persons requiring prescription glasses through the company furnished PPE plan shall get plastic framed prescription safety glasses.

4.1.1.11 No current-carrying conductors shall be opened without the use of a properly rated switch in the circuit. Do not cut cables or open connections without first verifying that there is no current flowing. This applies to both maintenance and demolition work.

4.1.1.12 When performing demolition work, qualified electrical persons shall positively verify that the cables and circuits are de-energized before cutting conduits, cable trays, supports, and associated wiring for removal.

4.1.1.13 No person shall authorize, perform, nor permit alterations or modifications to equipment, circuits, or protective device settings without written authorization from the system engineer. This includes, but is not limited to, switchgear modifications, removal or bypass of device contacts from control circuits, and the installation of temporary back feeds.

4.1.1.13.1 Any setting changes on breakers or protective relays on 480V or greater systems shall be coordinated and approved by the Power Control Power System Analysis Systems Engineer and/or the Power Control Arc Flash Systems Engineer. Changing settings on a protective device will alter the arc flash ratings of the downstream equipment and could put personnel at risk if the required level of PPE is not appropriately documented on the equipment.

4.1.1.14 Employees shall use insulated tools and/or handling equipment when working inside the restricted approach boundary of live parts. Insulated tools shall be protected from damage to the insulating material. Insulated tools shall be rated for the voltages on which they are used. Insulated tools shall be designed and constructed for the environment to which they will be exposed and the manner in which they are used. Insulated tools shall be inspected for damage prior to use.

4.1.1.15 Underground Electrical Lines and Equipment: Before excavation starts, Master Work Permit Section IV must be approved to identify and mark the location of the electrical lines or equipment. When it has been determined that a reasonable possibility of contacting energized electrical lines or equipment exists, appropriate safe work practices and PPE shall be used during the excavation.

4.1.1.16 Cutting or Drilling: Before cutting or drilling into equipment, floors, walls, or structural elements where a likelihood of contacting energized electrical lines or parts exists, the employee shall perform a risk assessment to:

4.1.1.16.1 Identify and mark the location of conductors, cables, raceways, or equipment. When potential circuits are not visibly exposed, Master Work Permit Section IV must be completed and a dig permit issued prior to cutting or drilling.

4.1.1.16.2 Create an electrically safe work condition

4.1.1.16.3 Identify safe work practices and PPE to be used

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4.1.2 General Testing Requirements

4.1.2.1 Test equipment, instruments, and their accessories shall be rated for the circuits to which they will be connected and shall be designed for the environment in which they will be used.

4.1.2.2 A suitable potential test device shall be used when testing high-voltage circuits. The tester is fastened to a hot stick by a universal tool attachment. These testing devices are available on base in ranges 1-40kV and 16-161kV for use by the AEDC workforce.

4.1.2.3 The tester shall be evaluated for proper operation immediately before and after each test.

4.1.2.4 Testing shall be repeated for each phase to confirm that the equipment is de-energized. Arc flash and shock

PPE appropriate for the hazard level is required when performing the test.

4.1.2.5 All electrical test equipment shall be stored in a clean dry location, kept clean and in good operating condition.

Voltage tester leads shall be protected to prevent damage by other objects.

4.1.2.6 Test equipment that has been exposed to excessive moisture shall be immediately removed from service and may not be returned to service until repaired and tested to assure its safe operation. Any equipment removed from service shall be identified or labeled as such to prevent inadvertent use.

4.1.2.7 Solenoid-type testers (commonly known as “wiggies”) are not approved for use as a means for verifying absence of voltage for personnel safety.

4.1.2.8 High-Voltage Insulation Testing Requirements

4.1.2.8.1 Qualified electricians and linemen shall perform isolation, tagging, disconnecting, and grounding procedures as required prior to testing. The qualified electrical person will direct the qualified electricians or test technicians as to which grounds shall be removed before testing.

4.1.2.8.2 The qualified electrical person in charge of testing is responsible for the conduct of the tests and for dissemination of safety instructions to all personnel involved.

4.1.2.8.3 Two qualified electrical technicians (or one technician and a qualified electrician or lineman) shall be assigned for high-voltage testing to ensure tests are performed safely.

4.1.2.8.4 All safety requirements for working near energized electrical circuits shall be followed.

4.1.2.9 Barrier Requirements

4.1.2.9.1 A barrier, denoting DANGER: HIGH-VOLTAGE TESTS IN PROGRESS shall be placed around equipment to be tested. Barriers may consist of distinctive flexible safety line (for example, red-and-black polypropylene rope or orange plastic tape) combined with signs denoting DANGER: HIGH-VOLTAGE TESTS IN PROGRESS.

4.1.2.9.2 All personnel in the immediate area shall be notified that the equipment is to be considered HOT OR

ENERGIZED.

4.1.2.9.3 With a hold order in effect, voltage should not be applied to the electrical equipment. The hold order shall be temporarily suspended to ensure other workers have cleared out of the potentially energized area.

4.1.2.9.4 When testing cables, the same protection on both ends of the cables shall be provided. If necessary, a second person shall be posted at the other end of the cables to ensure personnel in that area do not come in contact with the cables under test.

4.1.2.9.5 Both the person responsible for testing and the person operating test equipment shall confirm that all necessary barriers are in place before test potential or current is applied and shall determine that all persons likely to be in the vicinity are familiar with the significance of the barriers. In some circumstances a guard may be necessary.

4.1.2.10 Grounding after Tests:

Most direct current (DC) high voltage test sets have a means of shorting the high-voltage terminal to ground when testing is complete. Grounds shall then be reapplied with the same precautions as the original grounding operation. Grounds shall be left in place to discharge any residual charge accumulated during the test.

4.1.3 Grounding Requirements:

Grounding is the most effective way of protecting electrical workers from electric shock. It is important to ensure that all de-energized lines and equipment are grounded before performing repair work on them unless an EEWP to work them energized has been obtained.

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4.1.3.1 All conductors, overhead shield-wires, circuits, and equipment shall be treated as energized at full potential until they are determined to be de-energized and grounded.

4.1.3.2 Grounds shall be installed using a hot stick.

4.1.3.3 Approved, tested, and inspected high voltage rubber gloves of the proper rating, with leather protectors are required when installing grounds.

4.1.3.4 Except on Gas Insulated Switchgear (GIS), grounds should not be placed using a circuit breaker as a part of the grounding path as they can be opened. Switches can be used only if the switch is locked in the closed position after the ground path is established.

4.1.3.5 Various levels of Arc Flash PPE (AR work shirt and pants, coveralls, or flash suit with a totally enclosed hood and high temperature polycarbonate viewing shield) may also be required, depending on the hazard level as specified in Annex D or posted per Annex C.

4.1.3.6 Steps shall be taken to eliminate the possibility that temporary grounding leads might be overlooked when energy is restored. When installed inside equipment enclosures, temporary grounds shall be made highly visible.

4.1.3.7 When attaching grounds to lines or equipment, the grounding cable shall first be connected to ground, then to the lines or equipment. When removing grounds, the grounding cable shall be disconnected from the lines or equipment first and from the ground last.

4.1.3.8 Clamp and cable capacity shall be adequate for ground fault capacity of the circuit being connected to and all connections shall be clean.

4.1.3.9 Protective grounds shall have an impedance to ground low enough to permit prompt operation of protective devices in case of accidental energizing of the lines or equipment.

4.1.3.10 All personal protection grounds shall be either 2/0 or 4/0 copper grounds as required based on system available fault current.

4.1.3.11 Conductors on which repair work is to be performed shall be short-circuited and grounded between the work location and all sources of energy and as close as practical to the work location unless approval to work them energized (EEWP) has been obtained. Where possible, work shall be performed between grounds.

4.1.3.12 When working on a circuit that is adjacent to or parallels an energized circuit, the de-energized circuit (to be worked on) shall be grounded and short-circuited between the work location and all sources of energy and grounded at the work location.

4.1.3.13 Buses and equipment de-energized for repairs or changes shall be grounded on the source side of the working area. They shall also be grounded if located close to other energized conductors or equipment.

4.1.3.14 When a mobile crane or other lifting equipment is used and it is physically possible to contact energized lines or equipment, the truck or equipment shall be grounded, barricaded, and considered energized.

4.1.3.15 When a truck, mobile crane, or other equipment is considered energized, employees standing on the ground shall avoid contacting the truck, crane, or equipment unless suitable PPE is used. An insulated access shall be used for persons getting on and off the truck, crane, or equipment.

4.1.3.16 Protection from Step and Touch Potentials

4.1.3.16.1 Step potential is the voltage between the feet of a person standing near an energized grounded object. It is equal to the difference in voltage, given by the voltage distribution curve, between two points at different distances from the “electrode”. A person could be at risk of injury during a fault simply by standing near the grounding point.

4.1.3.16.2 Touch potential is the voltage between the energized object and the feet of a person in contact with the object. It is equal to the difference in voltage between the object (which is at a distance of 0 feet) and a point some distance away. It should be noted that the touch potential could be nearly the full voltage across the grounded object if that object is grounded at a point remote from the place where the person is in contact with it. For example, a crane that was grounded to the system neutral and that contacted an energized line would expose any person in contact with the crane or its un-insulated load line to a touch potential nearly equal to the full fault voltage.

4.1.3.16.3 Several methods may be used to protect employees from hazardous ground-potential gradients; e.g., equipotential zones, insulating equipment, and restricted work areas.

4.1.3.16.3.1 Equipotential Zone: Such a zone can be produced through the use of a metal mat connected to the grounded object. In some cases, a grounding grid can be used to equalize the voltage within the grid.

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Equipotential zones will not, however, protect employees who are either wholly or partially outside the protected area. Bonding conductive objects in the immediate work area can also be used to minimize potential between objects and between each object and ground. (Bonding an object outside the work area can increase touch potential to that object in some cases.)

4.1.3.16.3.2 Insulating Equipment: Use of insulating equipment, such as rubber gloves, can protect employees handling grounded equipment and conductors from hazardous touch potentials. Insulating equipment shall be rated for the highest voltage that can be impressed on the grounded objects under fault conditions (rather than for the full system voltage).

4.1.3.16.3.3 Restricted Work Areas: Restricting employees from areas where hazardous step or touch potentials could arise can protect employees not directly involved in the operation being performed. Employees on the ground in the vicinity of transmission structures shall be kept at a distance so that step voltages will be insufficient to cause injury. Employees shall not handle grounded conductors or equipment likely to become energized to hazardous voltages unless the employees are within an equipotential zone or are protected by insulating equipment.

4.1.4 Testing without grounds:

Grounds that may become energized and prevent testing may be temporarily removed. The same protective measures shall be used when removing the grounds as were used when installing the grounds. Additional measures may be necessary to protect each exposed employee in case previously grounded lines or equipment becomes energized.

4.1.5 Personnel Working on High-Voltage Facilities Shall

4.1.5.1 Perform all work in accordance with the provisions of this standard and in compliance with all other applicable safety requirements.

4.1.5.1.1 Not wear articles such as loose chains, keys, watches, or rings.

4.1.5.1.2 Take precautions prior to contacting insulated conductors and never assume electrical insulation is intact.

4.1.5.1.3 Wear appropriate head, eye, and hearing protection, gloves, rubber sole shoes, shields and nonconductive clothing.

4.1.5.1.4 Never reach blindly into electrical cabinets or enclosed areas.

4.1.5.1.5 Ensure the work areas are well lit.

4.1.5.1.6 Secure electrical cabinet doors to prevent inadvertent closing.

4.1.5.1.7 Keep the work area clear of non-essential tools and equipment.

4.1.5.1.8 Handle conductive objects carefully when in the area of electrical equipment.

4.1.5.1.9 Identify all sources of electricity and take appropriate safety measures before proceeding with the work.

4.1.5.2 Ensure that only trained and qualified electricians and qualified linemen perform work on high-voltage electrical equipment.

4.1.5.3 Ensure two qualified electrical persons work together on energized or potentially energized circuits. If two qualified electricians (linemen) are not available, a designated electrical standby person shall be present.

This designated person shall be equipped with a level of protection equal to that of the qualified electrical person doing the work or the level of the upstream disconnecting device (whichever is greater).

4.1.5.4 Ensure only qualified electrical persons enter energized electrical substations and motor control centers and that an approved MWP has been issued where required. Unauthorized employees shall be accompanied by a qualified electrical person. Qualified electrical persons shall not enter an electrical substation without permission from the on-duty power systems dispatcher or power switchboard operator.

4.1.5.5 Never change oil in a transformer while it is energized.

4.1.5.6 Do not allow a person atop a transformer while it is under vacuum during oil change operations.

4.1.6 Line Clearance Tree Trimming

4.1.6.1 Only qualified linemen shall be permitted to work on overhead lines operating at greater than 600V.

4.1.6.2 Qualified linemen shall be responsible for line-clearance tree trimming.

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4.1.6.3 Before an employee climbs, enters, or works around any tree; a determination shall be made of the nominal voltage of electric power lines posing a hazard to employees. However, a determination of the maximum nominal voltage to which an employee will be exposed may be made instead, if all lines are considered as energized at this maximum voltage.

4.1.6.4 There shall be a second line-clearance tree trimmer within normal (unassisted) voice communication under the following conditions:

4.1.6.4.1 If a line-clearance tree trimmer is to approach within 10 feet of any conductor or electric apparatus energized greater than 750 volts

OR

4.1.6.4.2 If branches or limbs being removed are within 10 feet of lines energized greater than 750 volts

OR

4.1.6.4.3 If roping is necessary to remove branches or limbs from such conductors or apparatus, line-clearance tree trimmers shall maintain minimum approach distances from energized conductors per the tables below:

AC Live-Line Work Minimum Approach Distances Distance

Phase-to-ground exposure Phase-to-phase exposure Nominal voltage in kV phase to phase (ft – in) (m) (ft – in) (m)

0.05 to 1.0 (see note 3) (see note 3 ) (see note 3 ) (see note 3 )

1.1 to 15.0 2-1 0.64 2-2 0.66

15.1 to 36.0 2-4 0.72 2-7 0.77

36.1 to 46.0 2-7 0.77 2-10 0.85

46.1 to 72.5 3-0 0.90 3-6 1.05

72.6 to 121 3-2 0.95 4-3 1.29 138 to 145 3-7 1.09 4-11 1.50 161 to 169 4-0 1.22 5-8 1.71 230 to 242 5-3 1.59 7-6 2.27 345 to 362 8-6 2.59 12-6 3.80 500 to 550 11-3 3.42 18-1 5.50 765 to 800 14-11 4.53 26-0 7.91

NOTE 1: These distances take into consideration the highest switching surge an employee will be exposed to on any system with air as the insulating medium and the maximum voltages shown.

NOTE 2: The clear live-line tool distance shall equal or exceed values for the indicated voltage ranges.

NOTE 3: Avoid contact.

DC Live-Line Work Minimum Approach Distance With Overvoltage Factor

Distance in feet-inches Maximum line-to-ground voltage in kV

Maximum anticipated per-unit transient overvoltage 250 400 500 600 750

1.5 or lower 3-8 5-3 6-9 8-7 11-10

1.6 3-10 5-7 7-4 9-5 13-1

1.7 4-1 6-0 7-11 10-3 14-4

1.8 4-3 6-5 8-7 11-2 15-9

NOTE 1: The distances specified in this table may be applied only where the maximum anticipated per-unit transient overvoltage has been determined by engineering analysis and has been supplied by the employer. However, if the transient overvoltage factor is not known, a factor of 1.8 shall be assumed.

NOTE 2: The distances specified in this table are the air, bare-hand, and live-line tool distances.

4.1.6.5 Branches contacting exposed energized conductors or equipment, or within the distances specified in the tables above (Section 4.1.6.4.3) shall be removed only through use of insulated equipment. Use clean, dry tools insulated for the voltage.

4.1.6.6 Use of ladders, platforms, and aerial devices shall comply with distances listed in the tables above (Section 4.1.6.4.3) unless approval to work them energized (EEWP) has been obtained.

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4.1.6.7 Line-clearance tree-trimming work shall not be performed when adverse weather conditions make work hazardous.