busman
Senior Member
- Location
- Northern Virginia
- Occupation
- Master Electrician / Electrical Engineer
I know you won't be able to give specifics. However, was working in a plant with the following configuration:
500 kVA Transformer at 13,800 primary / 480V secondary
30' bus duct to switchgear room
400A Square-D I-line circuit breaker feeding 150' 500MCM (not paralleled) - for comparison, this circuit breaker enclosure is listed at 38 cal/cm2.
The question: Panelboard at load end of the feeder is labeled as 2 cal/cm2. This seems low to me. My experience of 480V equipment is that it is not usually this low. Any comments based on your experience would be greatly appreciated. I do much more residential than anything else.
Thanks,
Mark
500 kVA Transformer at 13,800 primary / 480V secondary
30' bus duct to switchgear room
400A Square-D I-line circuit breaker feeding 150' 500MCM (not paralleled) - for comparison, this circuit breaker enclosure is listed at 38 cal/cm2.
The question: Panelboard at load end of the feeder is labeled as 2 cal/cm2. This seems low to me. My experience of 480V equipment is that it is not usually this low. Any comments based on your experience would be greatly appreciated. I do much more residential than anything else.
Thanks,
Mark