tryinghard
Senior Member
- Location
- California
I?m installing a 200A meter main and want to double check the service entrance size, an Article 220 load calc equals 144A. Is 1/0 cu THHN compliant for the service entrance?
Table 310.15(B)(7) seems to be based on service size. Service size is based on calculated load.
Table says 2/0AWG CU is the minimum
The number changed in 2011You beat me to it.
Is table 310.15 (B) (7) in to 2011? I don't see it in 2008. It's 310.15 (B) (6)
The first two sentances of 230.42 seem to say ampacity per Art 220, but then 310.15 must trump?
What I mean is how 230.42 starts "The ampacity of the service-entrance conductors...shall not be less then either 230.42.A.1 or A.2"Art 220 doesn't say anything about ampacity, Art. 220 is about the "load."
230.42 says loads shall be determined by Art 220 and Ampacity shall be determined by 310.15.
What I mean is how 230.42 starts "The ampacity of the service-entrance conductors...shall not be less then either 230.42.A.1 or A.2"
appears to state ampacity of SE conductors two different ways (but I think I'm over-reading it):I'm still not sure I understand what you mean. It says the ampacity of the service-entrance conductors shall not be less than 100% of the non-continuous load plus 125% of the continuous load, OR not less than 100% of the non-continuous plus continuous load when you have a 100% rated OCPD assembly.
The load shall be determined from Article 220, and the ampacity shall be determined from 310.15.
appears to state ampacity of SE conductors two different ways (but I think I'm over-reading it):
1 - "The ampacity of the service-entrance conductors...shall not be less then either 230.42.A.1 - the sum of the noncontinuous loads plus 125% of continuous loads..."
and
2 - "Ampacity shall be determined from 310.15"