cable size for service
- Thread starter j rae
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A lot of variables could effect the answer.
If you are talking copper it would normally be (3). (380 x 3 =1140)
Aluminum (4) (310 x 4 = 1240)
Termination ratings and ambient could change the answer,
The key is in 240.4(B) which states the ampacity must be equal or greater than the breaker if the breaker is over 800 amps.
An argument could be made for a smaller rating if the service disconnect is a motor load only and 430.52 was in effect.
If you are talking copper it would normally be (3). (380 x 3 =1140)
Aluminum (4) (310 x 4 = 1240)
Termination ratings and ambient could change the answer,
The key is in 240.4(B) which states the ampacity must be equal or greater than the breaker if the breaker is over 800 amps.
An argument could be made for a smaller rating if the service disconnect is a motor load only and 430.52 was in effect.
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