Residential service. When to run the 4th wire.

[sosuaveone]

I just finished installing a 100 amp overhead service with no disconnect. Panel is directly behind meter. I ran 2 hots and a neutral to this panel with main lugs only. Ground/neutral bar in this panel is bonded to the panel. Inspector tells me to run a ground to the meter and its good to go. I tried to explain that this would be running wires in parallel and that we are not isolated and insulated, but couldn't get thru to him. He then told me I needed a main breaker. This panel has 3 circuits total.

Can someone please send me the sections in the NEC that explain both of these? Unless something has changed, I was still under the impression that the panel does not need a main if there are 6 or fewer motions to shut it all down.

Thanks for the help folks,
Dennis O'Toole

 

[jap]

Unless he's talking about the Grounding Electrode Conductor from the meter to the grounding system You're correct.

The Neutral or Grounded Conductor is the return path from the panel back to the utility transformer.

There should not be parallel paths from the panel to the meter although there's most times no way around that.

Hang in there.

JAP>

 

[roger]

I agree with Jap, your inspector needs some schooling.

Roger

 

[synchro]

There are some places that have an amendment requiring a main breaker. So check if that might be the case.

 

[infinity]

I just finished installing a 100 amp overhead service with no disconnect. Panel is directly behind meter. I ran 2 hots and a neutral to this panel with main lugs only. Ground/neutral bar in this panel is bonded to the panel. Inspector tells me to run a ground to the meter and its good to go. I tried to explain that this would be running wires in parallel and that we are not isolated and insulated, but couldn't get thru to him. He then told me I needed a main breaker. This panel has 3 circuits total.

Can someone please send me the sections in the NEC that explain both of these? Unless something has changed, I was still under the impression that the panel does not need a main if there are 6 or fewer motions to shut it all down.

He's incorrect on two counts, one you have three service disconnects so no single main is required and secondly, you're correct, adding a "ground" is not required and actually prohibited because you're creating a parallel pah for the neutral current.

 

[electrofelon]

An indirect requirement for a main breaker could be AIC rating of the breakers. Typically a main will be 22k which will series rate with 10k branches.

 

[sosuaveone]

Thanks for the feedback. The inspector wanted to believe me on the 4th wire issue, but asked for the code. I don't always have the big book with me. I really wish there was an NEC app that would allow us to search codes quickly. If anyone knows of something like this please let me know.

Article 230.71 is where I found the 6 switch rule. Just realized im working with a 2014 book. Hope its still the same. Time to update!

 

[electrofelon]

See 250.92, 250.24(A)(5), (B) and (C)