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[puckman]

When doing the arc fault survey on 480v 3000 amp switch gear and the service transformers are on company property and the primary is lets say 4160v, is the primary or the secondary voltage used when doing the calc. for switch gear? Some one used a default hrc2 for company wide work, and was thinking this would change things. Let me say I doubt if anyone would be working on that side .

 

[jim dungar]

You perform calculations using the voltage and fault current based on the point where you are interfacing with the equipment. It makes no difference what voltages and current exist elsewhere in the facility. The only exception is at a transformer terminals where you may be exposed to two voltages and two different fault currents.