electrical safe work practices

MARQUETTE UNIVERSITY
ELECTRICAL SAFE WORK PRACTICES
_________________________________________________________________________________________________________________
PURPOSE
The purpose of this procedure is to protect all workers from injuries resulting from exposure to arc
flash, arc blast and electrical shock and to comply with NFPA 70E Standard for Electrical Safety
Requirements for Employee Workplaces – 2004 Edition and Federal OSHA CFR 1910.300 series
Subpart S-Electrical and 1926.400 series - Subpart K-Electrical.
IMPACT
No University employees or contractors engaged by Marquette University are permitted to work on
energized equipment unless:
 They are authorized employees.
 They have been trained.
 They are attired and equipped appropriately.
RESPONSIBILITIES
Authorized Employees: Authorized employees and employees of approved electrical contractors are
the only individuals qualified to work on electrical equipment on behalf of Marquette University. An
authorized employee is a qualified employee who has also completed Marquette University’s 70E
Electrical Safety Training Program.
Authorized employees are:
 Responsible for stopping work immediately and notifying the Maintenance Coordinator if
he/she is unsure of ability, scope of work or pending safety issue, at any time in the work day;
 Responsible for reporting all unsafe acts or conditions to their immediate supervisor;
 Responsible for inspecting and wearing required personal protective equipment.
Maintenance Coordinator: The Maintenance Coordinator is responsible for determining the feasibility
of de-energization depending upon the situation. When de-energization is not feasible, the
Maintenance Coordinator must:
 Pre-plan the task and complete an energized electrical work permit;
 Select the most “qualified” individual(s) to perform the task;
 Provide the appropriate personal protective equipment (PPE);
 Follow up to ensure that the PPE is worn and the task pre-plan is executed properly;
 Maintain completed permits on file.
Operations Manager: The Operations Manager is responsible for reviewing completed energized
work permits to ensure that work practices are compliant with Marquette’s electrical safety program.
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SAFE WORK PRACTICES
Marquette University’s policy is to avoid energized work whenever possible. Appropriate
planning and coordination shall be completed to ensure that systems are de-energized.
University employees are permitted to:
 Work in panels (Hazard Class 0 – 2*);
 Change ballasts;
 Install receptacles, outlets, tubes, bulbs and switches;
 Troubleshoot disconnects, starters, contactors and/or similar electrical components.
Marquette personnel are not permitted to:
 Work on electrical systems operating at greater than 600 volts;
 Engage in any activity that is rated higher than Hazard Class 2* (per 70E);
 Work in motor control centers (MCC’s), switchgear and other high voltage equipment
(energized or de-energized).
When circumstances mandate that a system must remain energized, the Maintenance
Coordinators shall take appropriate action to comply with the requirements of working on
energized electrical equipment.
Lockout/Tagout: The first consideration is always to de-energize and lockout/tagout, and ground
where appropriate, prior to work. Identify all energy sources and apply lockout and tagout devices to
all energy isolating devices to provide an electrically safe work condition. Refer to Marquette
University’s Lockout/Tagout policy for these requirements. Energy sources may include but are not
limited to; electrical, batteries, capacitance, mechanical, hydraulic, air, chemical, and potential stored
energy (springs, gravity).
Authorized employees must observe the following practices:
 Left Hand Disconnect Rule: Use the left hand rule when opening the disconnect. Stand to
the side of equipment. Do not stand in front of it when opening the disconnect.
 “Test Before Touch” – it could save your life. Always verify that the equipment was locked
out properly by testing for voltage using an adequately rated voltage tester. Wear appropriate
personal protective equipment while voltage testing.
The vast majority of tasks should be completely de-energized. Careful planning enables the
majority of the work to be completed while de-energized. When terminating or adding a circuit
breaker, de-energize the panel and complete the task.
For occupied buildings, scheduling a shutdown is always the preferred method to eliminate the risk of
injury and unplanned system outages.
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September, 2004
OSHA’s position regarding energized work is:
OSHA 1910.333(a)(1) requires that live parts be de-energized before a potentially exposed employee
works on or near them. Exception- if de-energizing introduces additional or increased hazards or if
de-energizing is infeasible due to equipment design or operational limitations. Examples are:




Interruption of life support equipment
Deactivation of emergency alarm systems
Shutdown of hazardous location ventilation
equipment
Removal of illumination from an area

Performing diagnostics and testing (e.g. start
up and trouble shooting circuits that are part of
a continuous process that would otherwise
need to be completely shutdown in order to
permit work on one circuit or piece of
equipment.)
Qualifications & Authorization: Only “qualified “ employees are permitted to work on or near
energized equipment. Qualified employees must be trained in electrical safe work practices by
attending Marquette’s NFPA 70E seminar and they must be authorized by Marquette to perform the
work.
The Maintenance Coordinator is responsible for selecting the appropriate “qualified” person for
energized work activities based on the individual’s experience and expertise. When an individual has
been trained (i.e. qualified), it doesn’t mean they can automatically perform energized work activities
without prior knowledge, input and approval from the Coordinator. The Maintenance Coordinator may
determine that the employee is not the most qualified person for the job. Qualified individuals must
also be authorized by the Maintenance Coordinator to perform energized work. It is anticipated that
the vast majority of electrical work performed by Marquette personnel will be on equipment below 240
volts. Only designated, qualified personnel will be permitted to work on 240-600 volt circuits and
these individuals will be identified by the Maintenance Coordinators.
No one shall perform work on or near energized conductors unless authorized by the Maintenance
Coordinators.
General Safe Work Practices:
a) The Maintenance Coordinators will determine the number of personnel required to complete
the task. The Maintenance Coordinator will determine if a standby person or emergency
communication is required.
b) Marquette personnel shall not perform energized work on equipment for convenience or take
unnecessary risks.
c) All authorized personnel shall be completely familiar with equipment layout and circuitry.
d) All parties involved shall know where and how to de-energize the source of power.
e) Conductive articles of jewelry and clothing, such as watchbands, bracelets, rings, key chains,
necklaces, metalized aprons, cloth with conductive thread, metal headgear or metal frame
glasses, shall not be worn where they present an electrical contact hazard with exposed live
parts.
f) When an employee’s alertness is impaired due to illness, fatigue or other reasons, the
employee is prohibited from working in areas containing live parts.
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September, 2004
g) Protective shields, protective barriers or insulating materials shall be used to protect
employees from injury while working on or near exposed energized components/equipment.
h) Employees will not blindly reach into energized equipment.
i) Employees shall avoid working in any position from which a shock or slip will bring the body
and/or tools into contact with exposed energized equipment.
j) Tasks that require handling large panel covers and dead fronts with dimensions of 20W x60H
and larger will require two employees.
k) Employees will test for phase-to-phase and phase-to-ground potential before installing any
circuit breaker bus switch into an energized or de-energized piece of equipment. Verify
component voltage rating is compatible for use.
l) Non-conductive “fish” tape or pulling line will be used any time conductors are pulled into
energized equipment.
m) Whenever raceways are added to energized equipment, all exposed bus and energized
components shall be covered with an approved insulating material (such as voltage rated
blanket), and shall be physically protected from shavings or dropped materials.
n) Where the possibility of induced voltages or stored electrical energy exists, ground the phase
conductors or circuit parts before touching them. Where it could be reasonably anticipated that
the conductors or circuit parts being de-energized could contact other exposed energized
conductors or circuit parts, apply ground connecting devices rated for the available fault duty.
o) It is necessary to determine whether there any possible back-feeds of the circuits.
p) Provide floor matting (insulated) where deemed necessary by the pre-plan.
q) Provide adequate lighting to perform task.
r) Clean up work area to eliminate all tripping hazards.
s) Cordon off the limited approach boundary or flash protection boundary. Ensure that all
unqualified people do not enter this area. For systems that are 600 volts or less, the Flash
Protection Boundary shall be 4 feet, based on the product clearing times of 6 cycles and the
available bolted fault current of 50 kA.
t) Notify affected people of the work to be performed.
u) Treat neutrals and grounds with the same care as “hot” phase conductors. Serious accidents
may result when neutrals or grounds are mishandled.
v) All energized work incidents (including near misses) must be reported to the Maintenance
Coordinator to investigate possible causes and corrective action.
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ELECTRICAL HAZARD ANALYSIS
When de-energizing is not feasible and work must be performed on or near energized conductors
operating at 50 volts or more, an electrical hazard analysis must be completed. The electrical hazard
analysis consists of a shock hazard analysis and a flash hazard analysis. These analyses shall be
documented by using the Energized Electrical Work Permit form. Only qualified, authorized
personnel will be permitted to work on or near live parts operating at 50 volts or more. Marquette
University personnel are not authorized to perform work that exceeds a Hazard/Risk Category of 2*
as defined by NFPA Hazard/Risk Category Classifications (130.7 (c)(9)(a)), under any circumstances.
When the Energized Electrical Work Permit can’t be completed because the task falls outside of the
70E tables, the task should be referred, by the Maintenance Coordinator, to an approved electrical
contractor.
Flash Hazard Analysis
The flash hazard analysis is performed to evaluate the possibility of injury due to arc flash. The
analysis determines the Flash Protection Boundary and the personal protective equipment that
qualified employees working within the flash protection boundary shall use. Use the NFPA 70E table
of Hazard Risk Category Classifications listed below for selecting the appropriate PPE. This table
identifies tasks by hazard risk category (Class 0-2*) and when V-rated gloves and tools are required.
For systems that are 600 volts or less, the Flash Protection Boundary shall be 4.0 ft., based on the
product of clearing times of 6 cycles (0.1 second) and the available bolted fault current of 50 kA or
any combination not exceeding 300 kA cycles (5000 ampere seconds).
Task (Assumes Equipment is Energized, and Work is
Performed Within the Flash Protection Boundary)
Panelboards Rated 240V and Below – Notes 1 and 2
Circuit breaker (CB) or fused switch operation with
covers on
CB or fused switch operation with covers off
Work on energized parts, including voltage testing
Remove/install CBs or fused switches
Removal of bolted covers to expose bare, energized
parts
Opening hinged covers to expose bare, energized parts
Hazard/Risk
Category
V-Rated
Gloves
V-Rated
Tools
0
N
N
0
1
1
1
N
Y
Y
N
N
Y
Y
N
0
N
N
Panelboards or Switchboards Rated >240V and up
to 600V (with molded or insulated case circuit
breakers) – Notes 1 and 2
CB or fused switch operation with covers on
0
N
N
CB or fused switch operation with covers off
1
N
N
Work on energized parts, including voltage testing
2*
Y
Y
Notes:
1. 25 kA short circuit current available, 0.03 second (2 cycle) fault clearing time.
2. For <10 kA short circuit current available, the hazard/risk category may be reduced by one number.
3. V-rated Gloves are gloves rated and tested for the maximum line-to-line voltage upon which work will
be done.
4. V-rated Tools are tools rated and tested for the maximum line-to-line voltage upon which work will be
done.
5. 2* means that a double layer switching hood (or equivalent) and hearing protection are required for this
task in addition the other 2 requirements.
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Shock Hazard Analysis
The shock hazard analysis determines the voltage to which personnel will be exposed, boundary
requirements and the personal protective equipment necessary in order to minimize the possibility of
electrical shock to personnel. The shock protection boundaries identified as Limited, Restricted and
Prohibited Approach Boundaries are applicable to the situation in which approaching personnel are
exposed to live parts. Refer to Table 130.2 (c):
Nominal System
Voltage Range,
Phase to Phase
Less than 50
50 to 300
301 to 750
Limited Approach
Boundary – Exposed
Fixed Circuit Part
(qualified/unqualified)
Not specified
3 ft 6 in.
3 ft 6 in.
Restricted Approach
Boundary; Includes
Inadvertent
Movement Adder
(qualified with
protective equip.)
Not specified
Avoid contact
1 ft 0 in.
Prohibited Approach
Boundary
(Work is considered
same as making
contact with live part)
Not specified
Avoid contact
0 ft 1 in.
ENERGIZED ELECTRICAL WORK PERMIT
Pre-plan the task using the Energized Electrical Work Permit form (Attachment) for all energized work
tasks Class 1 and greater. Describe the task and the specific reason the equipment can’t be deenergized or the work deferred until the next scheduled outage. Identify the personnel assigned the
task, the potential hazards, controls, PPE and tools needed. Review the Energized Electrical Work
Permit with all employees assisting in the operation and obtain their signatures. This review is
considered to be the job briefing and will be documented with the completed permit. A brief
discussion is satisfactory if the work involved is routine and if the employee, by virtue of training and
experience, can be reasonably expected to recognize and avoid the hazards. A more extensive
discussion shall be conducted if the work is complicated or particularly hazardous. The Maintenance
Coordinator and Operations Manager shall sign the permit to authorize the energized work per NFPA
70E 110.4.
The permit does not have to be completed for testing, troubleshooting and voltage measuring tasks.
However, the Maintenance Coordinator must be notified beforehand of these tasks. PPE use and
appropriate electrical safe work practices must still be followed while performing these tasks.
LIMITS OF APPROACH
Flash Protection Boundary: The distance at which there is sufficient energy on the skin surface to
result in a second-degree burn (i.e. 1.2 cal/cm2). Cordon off a work area around the equipment to
keep unqualified people out of the arc flash boundary of 4 feet. Only qualified people wearing
appropriate PPE can enter the flash protection boundary.
Cordon off the area using a method appropriate for the environment. For example, when working in a
panel in a hallway of an occupied office, set up a plastic barricade with chain or similar method to
keep unqualified people out of the arc flash boundary. When working in a locked electrical room or
remote area of a building, simply using some cones/signs and caution tape may be an appropriate
warning/barrier.
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September, 2004
Limited Approach Boundary: Only qualified people may cross the limited approach boundary.
Unqualified people must stay outside the boundary because they are unfamiliar with the electrical
shock hazards.
Restricted Approach Boundary: A qualified person must wear PPE for protection (typically rubber
gloves and use insulated tools) from the electrical shock hazard when working within the restricted
approach boundary.
Prohibited Approach Boundary: A qualified person must avoid performing work within the prohibited
approach boundary.
Personal Protective Equipment
Employees working in areas where electrical hazards are present shall be provided with, and shall
use, protective equipment that is designed and constructed for the specific part of the body to be
protected and for the work to be performed. Protective equipment shall be maintained in safe,
reliable condition and shall be visually inspected prior to each use. The PPE matrix shall be used to
identify requirements by hazard/risk category 0-2* (See attachment).
Definitions of Hazard Risk Categories in NFPA 70E Table:
Hazard Class
Class 0
Class 1
Class 2
Class 3
Class 4
ATPV (cal/cm2)
0 - 1.2
1.2 - 4.0
4.1 - 8.0
8.1 – 25.0
25.1 – 40.0
ATPV: Arc Thermal Performance Value: It is defined in ASTM P S58 standard arc test method for
flame resistant fabrics as the incident energy on a fabric or material that results in sufficient heat
transfer through the fabric or material to cause the onset of a second degree burn (1.2 cal/cm2).
Consensus standards define an injury when the energy reaches the skin to begin a second-degree
burn or “curable burn”.
Safety Glasses
Safety Glasses are required for all energized work tasks. All safety glasses must be non conductive
(no metal frames). This includes prescription safety glasses.
Face Shield and Hoods: For low-level electrical hazards (Class 1-2), an arc flash face shield
attached to the hard hat will provide adequate protection (8-10 cal/cm2). Safety glasses must be
worn underneath the face shield. Clear face shields do not provide adequate arc flash protection.
Safety glasses are required for all hot work tasks including Class 0.
2* tasks require a double layer switching hood or its equivalent.
Flame Resistant (FR) Clothing: FR clothing is available depending upon the application. The
electrical safety kits are equipped with hooded jackets made of Indura Ultrasoft. The jacket provides
a minimum of 11 cal/cm2 of protection (9.0 oz fabric).
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Wear a long sleeve natural fiber shirt and pants (cotton) preferably denim for all hot work tasks
including Class 0.
Complete a visual inspection of protective garments before each use and after washing. Report any
defects (torn fabric, ripped stitching, etc) to the Maintenance Coordinator.
Underlayers: Remember to wear natural fiber clothing (cotton) under your flame resistant clothing.
These underlayers not only include your shirt and pants but also underwear. An arc flash can create
enough heat to melt clothing underneath your flame resistant clothing. The heat will pass through the
flame resistant clothing even though it will not catch on fire or break open. Absolutely no synthetic
materials, such as polyester, nylon, and synthetic-blends can be worn during energized work.
Washing: Machine wash FR clothing separately using a detergent. Do not use chlorine bleach.
Tumble dry on low. Do not line dry in sunlight.
Insulating Gloves With Protectors: Verify that gloves have passed a voltage test within the past 6
months. 500-volt gloves are located in the electrical safety kits. When insulating rubber gloves are
used for shock protection, leather protectors shall be worn over the rubber gloves.
Before each use, visually inspect your gloves and complete an air test. Inspect rubber gloves for
holes, rips or tears, ozone and UV damage and signs of chemical deterioration. Complete an air test
to make it easier to detect damage. Roll the cuff of the glove tight to trap air inside then apply
pressure to areas of the glove to inspect and listen for escaping air. Then repeat the procedure with
the glove turned inside out.
If there are any defects or irregularities in the rubber gloves, remove them from service and contact a
Maintenance Coordinator immediately. Damage would include physical damage (punctures, cuts,
abrasions), chemical deterioration (swelling, softness, hardening, stickiness) ozone deterioration and
other irregularities. Rubber insulating gloves can be damaged by many chemicals, especially
petroleum based products (oil, gasoline, hydraulic fluid), solvents, hand creams, pastes and salves. If
contact is made with these or other chemical products, the contaminant should be wiped off
immediately. Gloves should be cleaned using a mild soap and rinsed with clear water. The gloves
can then air dry.
Leather protectors must also be inspected. Metal particles, embedded wire, and abrasive materials
that could physically damage the rubber glove must be removed before using the protector.
Properly store rubber gloves in canvas bags to protect them from damage and extend service life.
Place the gloves flat in the canvas bag, and never force more than one pair into a bag. Folds and
creases strain rubber and cause it to crack from ozone prematurely.
Gloves should be retested after all energized work incidents.
INSULATING TOOLS
Voltage Rated Tools: Use Voltage rated tools when there is the potential for the tool to come in
contact with energized parts. Refer to the NFPA 70E table of Hazard Risk Category Classifications
for details on which tasks require voltage rated tools. Voltage rated tools are rated for 1000 volts and
labeled with a symbol.
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September, 2004
Inspect the condition of the tools prior to use. Remove damaged tools from service and contact a
Maintenance Coordinator.
ELECTRICAL SAFETY KIT
The contents of the electrical safety kit include:
1 Pair 500 Volt Max Rubber Gloves
1 Canvas Glove Bag
1 Flame Retardant Shirt/Jacket
1 Pair Leather Glove Protectors
1 Arc Protection Face Shield
1 Pair Non-Prescription Safety Glasses
Note: All items shall be returned to the Electrical Safety Kit after using.
Rubber Gloves: Twice a year, safety kit rubber gloves shall be exchanged for testing/inspection.
Electrical Safety Kit: The Maintenance Coordinators will check the Electrical Safety Kit on a
monthly basis to replace/repair any items. Employees will check the contents of the electrical safety
kit prior to each use and will report any deficiencies to a Maintenance Coordinator.
LABELING
Arc flash warning labels are posted on equipment – installed per NEC 2002. This is not a
requirement for equipment installed prior to 2002.
Switchboards, panelboards, industrial control panels and motor control centers shall be
marked to warn qualified persons of potential electrical arc flash hazards per NEC 2002 110.16. The
markings shall be located so as to be clearly visible to qualified persons before examination,
adjustment, servicing or maintenance of the equipment.
For panels, the markings should be placed on the outside cover where possible, because they need
to be visible before examination. On unit substations or large switchboards, the markings should be
placed on each compartment or section so they are clearly visible from the direction one approaches
the equipment. A marking/label is not required for individual switches but rather each access
compartment. Larger labels may be appropriate on larger equipment such as substations to make
them clearly visible.
The marking or labels will be similar to the one pictured below. These generic labels simply warn of
the arc flash hazard and to wear appropriate PPE.
Do not fill out and install labels that identify the Hazard Class (0-4), approach boundaries, incident
energy in calories/cm2 or similar information. A Professional Engineer must perform the incident
energy calculations to determine the appropriate information to put on these labels.
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September, 2004
TRAINING
Qualified personnel receive education on electrical safe work practices through several methods:
NFPA 70E: Qualified personnel are required to attend Marquette’s 4 Hour NFPA 70E seminar. All
workers must successfully complete a NFPA 70E seminar before they are authorized to perform
energized work tasks. Unqualified, untrained workers are not authorized to work on or near energized
equipment until it is placed into an electrically safe condition.
Marquette University- Electrical Safe Work Practices: This training expands upon the concepts
presented in NFPA 70E. It is a one hour session that details Marquette University’s electrical safety
program.
Tool Box Safety Talks: Safety talks on arc flash hazards, electrical safe work practices and NFPA
70E are available. The Maintenance Coordinators should conduct electrical safety toolbox talks as
necessary.
Job Site Specific Training: Additional on site training is provided as necessary. Electrical safe work
practices specific to the facility should be discussed with the affected authorized employees.
CONTRACTORS
All contractors engaged by Marquette University, who work on energized equipment on behalf of the
University, must be in compliance with the most recent edition of NFPA 70E Standard for Electrical
Safety in the Workplace and all other applicable local, state and federal regulations.
Attachments
Energized Electrical Work Permit form
Protective Clothing and Personal Protective Equipment (PPE) Matrix
Electrical Safety Toolbox Talks
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