SER question

[augie47]

Don't forget 230.79 has nothing to do with the service size only the disconnecting means size.

agree, Bob, and we may be playing semantics, but if he went to a 80 amp breaker would that not be considered the disconnect size ?
(I know the enclosure/panel might be rated higher)

 

[iwire]

but if he went to a 80 amp breaker would that not be considered the disconnect size?

I don't know.

I suspect, but do not know that a manufacturer would say that breakers from 15 to 100 are 100 amp frame size so maybe we could argue that but I would not want to bet money on an inspector buying into it.:grin:

I would say a 100 amp breaker followed by an 80 amp would work of a 100 amp fused switch with 80 amp fuses.

 

[Dennis Alwon]

Don't forget 230.79 has nothing to do with the service size only the disconnecting means size.

No but check out 230.42(B) and let me know what you think.

(B) Specific Installations. In addition to the requirements of 230.42(A), the minimum ampacity for ungrounded conductors for specific installations shall not be less than the rating of the service disconnecting means specified in 230.79(A) through (D).

 

[slick 50]

How about 310.15 (B) (6)

 

[iwire]

No but check out 230.42(B) and let me know what you think.

What I think?

(Sorry I just saw this older question)

It says what it says and it still does not require that a home have a 100 amp 'service'.

 

[Dennis Alwon]

What I think?

(Sorry I just saw this older question)

It says what it says and it still does not require that a home have a 100 amp 'service'.

Bob the service disconnect for a house must be 100 amps based on 230.79(C) correct?
230.42(B) states the amp. of the service conductors must not be less then the disconnect.

IMO, if 230.79 wants 100 amps for the disconnect then 230.42(B) clarifies the conductors must be also.

(B) Specific Installations. In addition to the requirements of 230.42(A), the minimum ampacity for ungrounded conductors for specific installations shall not be less than the rating of the service disconnecting means specified in 230.79(A) through (D).

 

[slick 50]

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How about 310.15 (B) (6)

 

[iwire]

Bob the service disconnect for a house must be 100 amps based on 230.79(C) correct?
230.42(B) states the amp. of the service conductors must not be less then the disconnect.

IMO, if 230.79 wants 100 amps for the disconnect then 230.42(B) clarifies the conductors must be also.

I agree with everything you have said above.

Regardless I could if I so chose to install a 100 amp fused switch with 100 amp conductors and install 30 amp fuses if that would be adequate for the calculated load.

The NEC does not specify a minimum service size.

 

[wireguy8169]

Love this forum