Safety issues concerning live panel box work

[ogbuehi]

I need to do a power quality analysis on a 120/208V panel box and main breaker. I'm trying to determine the amount of harmonics on UPS dedicated loads and commercial power loads in the building and do a load assessment on the commercial powered loads.. Due to the critical purpose this building serves power can't be shut down to hook the ammeter clamps around the lines and voltmeter clips to the bus. I don't have access to NFPA 70E or IEEE 1584 (I'm in Korea right now). I'm trying to get some formulas to determine the incidental energy of the box and to determine if I have enough PPE to do this live or not. We have FR 100% cotton clothes, Type I head gear, protective eyewear, class I rated gloves, and electrical safety boots. Any help concerning this would be very helpful.

 

[wbd]

what size is the transformer feeding this panel? If it is 125 kva or less, then IEEE 1584 states that it need not be considered in a arc flash hazard analysis, which is considered to mean a Cat #0.

 

[ogbuehi]

Thanks for the reply. They are 3 single phase 100kVA transformers feeding a main CB that then feeds the sub-panels. I'm assuming that the transformer size applies to any sub-panels being from it. Now I've seen plenty of 1MVA transformers (13.8kV-120/208V) feeding a main panel. Does the arc flash hazard analysis still apply to the sub-panels fed from that main?

 

[safetydan]

NFPA 70E applies to all panels over 50 volts.