Tip DS
I'm here.
- Location
- The Great Meme State
- Occupation
- Electrical Engineer
Third edition of UL 508a specifies the size of a feeder circuit's OCPD should be:
32.3.1(a) - The rating of the largest branch circuit protective device in the circuit plus 125% of all heater loads plus the full-load currents of all other motors or other loads in the group that could be in operation at the same time...
So, basically, it's the sum of all the loads PLUS the size of the largest OCPD. That largest OCPD's loads have already been counted.
Am I missing something, or is the addition of the largest breaker/fuse added buffer? Seems weird.
32.3.1(a) - The rating of the largest branch circuit protective device in the circuit plus 125% of all heater loads plus the full-load currents of all other motors or other loads in the group that could be in operation at the same time...
So, basically, it's the sum of all the loads PLUS the size of the largest OCPD. That largest OCPD's loads have already been counted.
Am I missing something, or is the addition of the largest breaker/fuse added buffer? Seems weird.