kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
I see what you are saying but under that line of reasoning shouldn't we do away with 310.15 (B)(6).
310.15(B)(6) is a different ballgame, the conductor must be supplying entire dwelling before it can be used. The load diversity is greater when supplying entire dwelling than when just supplying a portion of it.
You said in OP that this feeder was for HVAC equipment. HVAC equipment does not have much of a load diversity at all at times. If this feeder is sized close to actual HVAC load then the load plus the ambient temp will be more of a problem. I understand you are feeding this from subfeed lugs from the main panel and it likely is not going to be loaded to its capacity, and may never give any trouble, but that does not change the fact that you have a conductor that has an derated ampacity of maybe 125 amps being protected by a 200 amp overcurrent device. I don't know what justification an inspector would have to say this is acceptable. Run same conductor with same calculated load and same deration factors through a boiler room and I bet he does not accept it. Why is it any different?