# Generator Wiring Question



## abokc (Nov 28, 2016)

I am planning on having an electrician install a 30 amp inlet box and interlock kit at my house and I am wondering what gauge wire I should have him use. The inlet box will have probably 140'-150' of wire to tie it in at the breaker box. The electrician said either 10/3 or 8/3 would be fine. Does that seem like too far of a distance for the 10/3 to be carrying up to 30 amps? I am fairly new to all of the so I just want to make sure it is done properly. Thanks.


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## aandpdan (Oct 8, 2012)

A quick rule of thumb is that if the distance is greater than the voltage, increase the size of the wire. 

I'd go with the 8/3, it will reduce the voltage drop to just under 3%. You'd be near 4.5% with 10/3. 

IMHO, the wire isn't the most expensive part of the job, it's going to be the labor.


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## abokc (Nov 28, 2016)

Thanks for the input. I plan on having it run through the attic then down the side of an exterior wall to the inlet box. Do I have use UF-B wire in conduit since it will be outside? It should only be about 6' of wire on the outside of the house.


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## aandpdan (Oct 8, 2012)

Conduit is considered a damp location.

If the entire run is in conduit consider using THWN wire.


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## exmar (Jun 29, 2015)

JMHO, but you're paying (probably very well) a licensed electrician who's familiar with genset installations and your environment, etc. yet you're going to tell him how to do it? Seems like a recipe for a "situation" if something goes wrong and he says, "Hey, you said you wanted "X".


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## abokc (Nov 28, 2016)

What is wrong with trying educated yourself before you pay someone to do a job that you have minimal experience with??


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## exmar (Jun 29, 2015)

Again, JMHO, but a couple of casual online chats doesn't really enable you to have an intelligent conversation with someone who has had formal training and years of experience. You're to be congratulated in getting a professional to do the work. Ask him/her questions, prefaced with "I'm not familiar with this, just trying to understand a little." Contractors like to educate as it gives them an opportunity to reinforce that you did the right thing hiring them and preps you to call them for the next time.


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