- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
I was reviewing a set of plans and specs and an odd question came to my mind. I know how the NEC defines "supervised location," and I know there are instances in which the rules are less stringent in such locations. But how does a reviewer judge whether the designer inappropriately took advantage of such rules for a facility? In other words, do I need to verify that the facility has documented training that establishes the qualifications of their workers, or perhaps has documented maintenance procedures, or perhaps has documented processes for monitoring equipment status?
The issue of interest is a 12.5 kv to 480/277 v service transformer with the downstream breaker above 125% of the rated secondary current (but below 250%). That is allowed only in supervised locations, and I have nothing that tells me that the facility meets that description. Is it worth asking the designer to explain their basis for applying the 250% allowance?
The issue of interest is a 12.5 kv to 480/277 v service transformer with the downstream breaker above 125% of the rated secondary current (but below 250%). That is allowed only in supervised locations, and I have nothing that tells me that the facility meets that description. Is it worth asking the designer to explain their basis for applying the 250% allowance?