1st time operation of Circuit Breaker.

C

Cat Fan

Member
Location
Phoenix, Az, USA
Table 130.5(C) Estimate of the Likelihood of Occurrence table states, "Operation of a CB or switch the first time after installation or completion of maintenance in the equipment. likelihood yes. Since they added that in 2021 I have seen many different interpretations in the field. Some companies follow it diligently with electricians donning a 40 cal. suite for energizing 20 amp, 120V circuits, low incident energy breakers. Other companies for the higher incident energy, don the suit but for the smaller ones, wear leather protectors and make sure they stand off to the side, and finally the group that ignores it all and just does whatever they want. Was it the intent of NFPA70E team to group all breakers into this regardless to incident energy rating? I am currently working in a building where the distribution panels are energizing and compliance with the statement as written would involve approximately 1000 breakers. There is no exposed bussing for these panels, all dead fronts and panel covers are in place. All panels have incident energy labels installed.
 
NFPA 70E doesn't group everything together. It simply says you need to perform a risk analysis on each of your tasks. It also says turning a breaker on for the first time, after wiring has been done, is very risky, due to possible wiring faults, and therefore you should expect the maximum incident energy should a failure occur. This is different from the simple turn off and turn on of a circuit that is known not to have a fault in the wiring.

Some companies apparently do not trust their qualified employees to perform risk assessments and instead require maximum PPE regardless of what is available.
 
I agree. After first time energization operation of a CB is considered No in likelihood of occurrence. GC's with little understanding of risk assessment are looking at this black and white. I am trying to figure out how to present this in a way that allows for 1st time operation of branch circuits with minimal incident energy to be operated the same way I have been doing it for 30 years, leather protectors, stand to the side. This is a data center cal. rating at the SES is 120 and above, no PPE exist. At the subpanels it drops to 20 and lower. I need to be able to communicate the difference, but they get stuck on the black.
 
Sounds like someone has not been having regular NFPA 70E update training. Risk assessment has been required for more thann10 years now.
 
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