wire size

[ceb58]

Help a brain dead brother out. Generator 20Kw output 83 amps. Generator has a 125 amp breaker. I say wire must be sized to breaker and not the max out put. What is the code artical for this one way or the other?

 

[augie47]

IMO, 240.4. The OCP is 125 amp and the conductor must be sized accordingly.
The 20 kw gen could produce more than 83 amps short term.

 

[charlie b]

I agree with you. 240.4 says that the conductor must be protected against overcurrent at its ampacity. If you select a conductor rated only for 83 amps (let us say a #4 THHW), it would not be protected by a 125 amp breaker.

 

[augie47]

thats my thinking.

 

[ceb58]

Thanks Guys. After babysitting 3 of my Granddaughters for 2 hrs. my brain is fried
:dunce:

 

[cowboyjwc]

Thanks Guys. After babysitting 3 of my Granddaughters for 2 hrs. my brain is fried
:dunce:

2 hours? How did you last so long?:lol:

 

[ceb58]

2 hours? How did you last so long?:lol:

It was the 10 minutes they shut up to eat that saved me.:roll:

 

[Dennis Alwon]

Thanks Guys. After babysitting 3 of my Granddaughters for 2 hrs. my brain is fried
:dunce:

Is that all it takes to bring a big guy like you down. :lol:

 

[ceb58]

Is that all it takes to bring a big guy like you down. :lol:

Watch it Dennis, I'll put a 5 year old on you and when she finishes you'll look like a ballerina

 

[Cow]

Watch it Dennis, I'll put a 5 year old on you and when she finishes you'll look like a ballerina

I have a 7 year old and I agree with that statement.

:lol:

 

[cripple]

Wire size

Wire size

You may want check section 445.13

"445.13 Ampacity of Conductors
The ampacity of the conductors from the generator terminals to the first distribution device(s) containing overcurrent protection
shall not be less than 115 percent of the nameplate current rating of the generator. It shall be permitted to size the neutral conductors in accordance with 220.61. Conductors that must carry ground-fault currents shall not be smaller than required by 250.30(A). Neutral conductors of dc generators that must carry ground-fault currents shall not be smaller than the minimum required size of the largest conductor."

 

[tkb]

You may want check section 445.13

"445.13 Ampacity of Conductors
The ampacity of the conductors from the generator terminals to the first distribution device(s) containing overcurrent protection
shall not be less than 115 percent of the nameplate current rating of the generator. It shall be permitted to size the neutral conductors in accordance with 220.61. Conductors that must carry ground-fault currents shall not be smaller than required by 250.30(A). Neutral conductors of dc generators that must carry ground-fault currents shall not be smaller than the minimum required size of the largest conductor."

That article only applies from the generator output terminals to the first breaker, which is usually installed by the factory in the generator enclosure.

The feeder from the generator breaker must be sized per 240.4.

 

[qcroanoke]

That article only applies from the generator output terminals to the first breaker, which is usually installed by the factory in the generator enclosure.

The feeder from the generator breaker must be sized per 240.4.

Isn't that telling the manufacturer what wire to use? NEC does not cover that.

 

[tkb]

Isn't that telling the manufacturer what wire to use? NEC does not cover that.

The breaker doesn't have to be in the generator.
I have seen them in gear next to the generator.

 

[stevebea]

Help a brain dead brother out. Generator 20Kw output 83 amps. Generator has a 125 amp breaker. I say wire must be sized to breaker and not the max out put. What is the code artical for this one way or the other?

I installed a Kohler 20Kw generator this week and it came with a 100 amp breaker installed but a co-worker of mine installed a Kohler 20Kw a few weeks ago and it came with a 125 amp breaker installed. :?