We have an electrical panel required a 400A circuit breaker. From the NEC code book, the wire size of 500kcmil THHN in raceway at 90 degree C has an ampacity of 430A. The distribution block can't handle the wire size larger than #4/0. Please advise the properway to connect the power distributionto the circuit breaker.
wire size for 400A Circuit breaker
- Thread starter thip
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ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: wire size for 400A Circuit breaker
Is this panel listed as a 400 amp panel?
Is this panel listed as a 400 amp panel?
Re: wire size for 400A Circuit breaker
Well, it is doubtful your terminations are rated 90 deg so you will have to look at the 75 deg rating.
If the panel busses are rated 400 amps why are the lugs smaller, or are they parallel lugs?
Most panels can be ordered with whatever lugs you need for the installation.
Roger
Well, it is doubtful your terminations are rated 90 deg so you will have to look at the 75 deg rating.
If the panel busses are rated 400 amps why are the lugs smaller, or are they parallel lugs?
Most panels can be ordered with whatever lugs you need for the installation.
Roger
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Re: wire size for 400A Circuit breaker
Parallel sets of #3/0 THHN will give you 400 amps and will fit into your #4/0 block providing it has room for parallel terminations.
Parallel sets of #3/0 THHN will give you 400 amps and will fit into your #4/0 block providing it has room for parallel terminations.
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