- Location
- New Jersey
- Occupation
- Journeyman Electrician
The 350's are spliced to the 500's in the wireway and feed a 400 amp non-fused disco then a 400 amp main breaker panel.I get 350s to the left of the equipment.
The 350's are spliced to the 500's in the wireway and feed a 400 amp non-fused disco then a 400 amp main breaker panel.I get 350s to the left of the equipment.
Okay, I'm cross eyed again.Post 11, OP says they are 500 up to the gutter.
Because 240.4(b) allows you to round up to the next standard size circuit breaker. They don't make a 380A breaker so you're allowed to round up to the next standard size breaker. However, there are limitations to this.id prefer to use 500mcm, it always escapes me when can I
legally use 500mcm for a 400a service when 500mcm is only rated at 380 75degree?
Don't forget that if the load exceeds 380 amps, 500mcm won't get it. Parallel #3/0 or 600mcm will be needed.
Next size up rule ends once you go over 800 amps. People sometimes get into trouble with this thinking 500 copper is good for 400 amps and they run say three sets for a 1200 amp circuit. That gives you 1140 amps of conductor but you are no longer allowed to use next size up rule.Agreed, those are some of the limitations. Also, can’t be used on secondary side of a transformer off memory, or anything 800A or greater, etc.
I’m not an electrician but I do my own electrical work, and I’d much prefer to work with 2 sets of 3/0 wire vs. something like #500 or 600s.
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Next size up rule ends once you go over 800 amps. People sometimes get into trouble with this thinking 500 copper is good for 400 amps and they run say three sets for a 1200 amp circuit. That gives you 1140 amps of conductor but you are no longer allowed to use next size up rule.