For Arc Flash Labeling, is there a voltage (such as 240 Volts AC and below) and phase (such as single-phase) where Arc Flash Labels do not need (are not required) to be placed on electrical equipment?
Thank you - John Storm
It all needs to be labeled by the NEC but it does not need to have any real info - by the NEC. The NEC only requires a label. Without a study a label that states "arc flash hazard present" has no real meaning!
By the IEEE and NFPA-70E 240V does need to be labeled and 208 may need to be labeled (if over 125kVA) but there is no reliable method to label single phase, only three phase. The NESC, basically recommends 4.0 cal for single phase.
So we are now into five standards that we can go to for arc flash - NEC (NFPA-70), NFPA 70E, and NESC, IEEE-1584. NFPA 70E is tied to IEEE-1584, NFPA-70E is tied to NFPA-70(NEC), and NESC is tied to IEEE like 1584. You would think someone could get it together???
110.24 does not require the labeling in dwelling units at the service equipment, unless the service equipment is a service rated transfer switch. 702.5 requires transfer equipment to be labeled with the equipment's short circuit current rating.
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