Do you use #3 CU?

[quogueelectric]

#3 is good for 100a past the service. They do not sell it in texas for obvious reasons.

 

[Buck Parrish]

#3 is good for 100a past the service. They do not sell it in texas for obvious reasons.

What reason ?

 

[Chamuit]

I've tried to get it here but no one I deal with carries #3 CU. It's either #4 or #2.

 

[quogueelectric]

What reason ?

Texans think everything is bigger in Texas of course.

 

[Pullnwire]

I've tried to get it here but no one I deal with carries #3 CU. It's either #4 or #2.

I use it here, one supplier stocks it, but the other does not. "we can order it if you want"

 

[donw]

Chamuit, since you are in AZ, like me, that's what I wanted to hear. Do you think it's that way all around the Valley? I can't figure why, because it causes us to oversize for breakers in the 80A to 90A range.

 

[sparky76]

Pullnwire, I have same problem. One supplier won't stock it at all. The other one doesn't stock it normally, but they can get it from a nearby branch.

 

[john_axelson]

We use #3 all of the time. Specifying #2 instead of #3 may lead to a need to up size the EGC

You lost me, why does a change in wire size from #3 to #2 require a change in equipment grounding conductor? It has always been my understanding that the equipment grounding conductor is based on breaker size.

Did you mean the Grounding Electrode Conductor where the ground wire size is related to the Service-entrance conductor size?

We also use #3 all of the time.

 

[C3PO]

You lost me, why does a change in wire size from #3 to #2 require a change in equipment grounding conductor? It has always been my understanding that the equipment grounding conductor is based on breaker size.

Did you mean the Grounding Electrode Conductor where the ground wire size is related to the Service-entrance conductor size?

We also use #3 all of the time.

Look at 250.122(B)

 

[petersonra]

we sometimes end up using #2 where #3 would normally be used just because we can't get #3 as easily.

just depends on what is in stock at the supply house.

most of the time we only use a few dozen feet at a time in those sizes so it is not a big cost to upsize.

 

[LarryFine]

You lost me, why does a change in wire size from #3 to #2 require a change in equipment grounding conductor?

Probably because someone finding upsized conductors may one day need to upsize the breaker feeding it, and the EGC might need to be changed, but probably wouldn't be.

 

[john_axelson]

Probably because someone finding upsized conductors may one day need to upsize the breaker feeding it, and the EGC might need to be changed, but probably wouldn't be.

I understand the concept and theory, but, a #8 EGC is good to 200A OCPD, I don't see the benefit of upsizing from a #8 to a #6 when pulling either #3 or #2, even if you did change the breaker size.

 

[C3PO]

I understand the concept and theory, but, a #8 EGC is good to 200A OCPD, I don't see the benefit of upsizing from a #8 to a #6 when pulling either #3 or #2, even if you did change the breaker size.

How is a #8 EGC good to 200A? It looks to me like it is good to 100A.

 

[john_axelson]

How is a #8 EGC good to 200A? It looks to me like it is good to 100A.

you're right