Injury Illness Prevention Plan - Flipbook - Page 83
Health and Safety Program Manual
Teamwrkx
Construction, Inc.
x
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Electrical - Qualified
Arc Flash Safety
Issue Date: 10/16/23
Revision Date: 10/16/23
Reference: A-1
For systems of 600 volts and less, the flash protection boundary is 4 feet, based on an available
bolted fault current of 50 kA and a clearing time of 6 cycles for the circuit breaker to act, or any
combination of fault currents and clearing times not exceeding 300 kA cycles.
When working on de-energized parts and inside the flash protection boundary for nearby live
exposed parts - If the parts cannot be de-energized, use barriers such as insulted blankets to
protect against accidental contact or wear proper PPE.
See Appendix II – Arc Flash PPE Categories in NFPA 70E
Arc Flash Hazard Analysis
An arc flash hazard analysis includes the following:
x
Collect data on the facility’s power distribution system.
o Arrangement of components on a one-line drawing with nameplate specifications
of every device.
o Lengths and cross-section area of all cables.
x
x
x
Contact the electric utility for information including the minimum and maximum fault currents
that can be expected at the entrance to the facility.
Conduct a short circuit analysis followed by a coordination study is performed.
Feed the resultant data into the NFPA 70E equations.
o These equations produce the necessary flash protection boundary distances and
incident energy to determine the minimum PPE requirement.
o The flash protection boundary is the distance at which PPE is needed to prevent
incurable burns (2nd degree or worse) if an arc flash occurs. (It is still possible to
suffer 1st or 2nd degree burns.)
x
For systems of 600 volts and less, the flash protection boundary is 4
feet, based on an available bolted fault current of 50 kA (kiloamps) and
a clearing time of 6 cycles (0.1 seconds) for the circuit breaker to act,
or any combination of fault currents and clearing times not exceeding
300 kA cycles (5000 ampere seconds).
When working on de-energized the parts, but still inside the flash protection boundary for nearby live exposed
parts:
x
If the parts cannot be de-energized, barriers such as insulated blankets must be used to protect
against accidental contact or PPE must be worn.
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