How many subpanels can be fed from one disconnect?

[charlesaf3]

Discussion with chief inspector (city of Richmond VA, TJ if you are here, not Tab, he's gone) while he was inspecting a service upgrade. 400 amp meter on garage on alley, 400 amp disconnect, 50 feet of conduit through garage and buried to house to trough and 2 x 200 amp panels.

We would like to put a sub panel directly out of the disconnect, which would have 3 primary subpanels. Inspector feels that is not compatible with code, though he knows of no code provision banning it. So he told me he's going to AHJ us unless we can find a fairly specific code provision on the subject.

His theory is that we already have 400 amps of "primary" subpanels, and that the collective amperate of the subpanels cannot exceed that of the disconnect/meter (ironic since the meter is a 320 of course)

Is there a code provision for running an extra subpanel off the disconnect?

Plan B isn't the end of the world, we'd come back to a 100a sub in the garage off one of the 200s using mobile home feed (allowed here for residential)

 

[Eddie702]

I believe the inspector is wrong. The service has to be large enough for the computed load. It has never been the case that you add up the feeder circuit breakers and that they cannot exceed the service rating...they can and often do

 

[augie47]

Agree with Eddie.... There is no limit as tot he number of panels that can be off an overcurrent device.
You do need to assure your lugs are properly rated for the number of conductors and you comply with the 240.21 tap rules.

 

[jap]

Using that logic would be like saying I have 42 single pole 20's in my 200 amp Main Breaker Panel and it draws 840 amps,,,,

Jap>

 

[charlesaf3]

I believe the inspector is wrong. The service has to be large enough for the computed load. It has never been the case that you add up the feeder circuit breakers and that they cannot exceed the service rating...they can and often do

Yeah, that's our take. Exactly my thought on the breakers. But he needs a code section..

 

[charlesaf3]

Using that logic would be like saying I have 42 single pole 20's in my 200 amp Main Breaker Panel and it draws 840 amps,,,,

Jap>

100%!!

But as you might imagine, I said that with my "inside my head voice".

I'd like not to run conduit back to the garage, but that pales in comparison to pissing off the new Chief Inspector. He wasn't being mean about it, just said he needed a specific code section justifying. Neither he nor I can recollect such a thing.

I offered to swap one of the 200s for a 100 to put a 100 in the garage and he wasn't on board with that either. Which also doesn't make sense to me as the subs all have a main breaker, and the wire certainly wouldn't be undersized... But maybe I'm missing a balance issue?

 

[jap]

The whole running back from the 200 amp panel things is like when I have a project to do at home on the weekend.

I'll pass Lowes and Home Depot on the way home on Friday after work just to go back on Saturday to pick up what I need when I should have stopped there in the first place.

Jap>

 

[jaggedben]

230.79 and 230.42(A).

You will have to do the load calculation. I suggest using 220.82 or .83.

 

[infinity]

I'd like not to run conduit back to the garage, but that pales in comparison to pissing off the new Chief Inspector. He wasn't being mean about it, just said he needed a specific code section justifying. Neither he nor I can recollect such a thing.

This neopyhte chief needs some re-education. As mentioned several times the requirement is that it complies with a load calculation nothing more. Also it's not your job to provide a code section that's his job.

 

[Little Bill]

I agree with Rob, instead of you showing the inspector that you can by code, he needs to show you you can't by code. He sounds lazy, or just ignorant!

 

[Eddie702]

It's all about the load calculation. I did a 3 family service upgrade. Removed 3 60a panels and installed 3 100 amp panels. The service entrance can out to 200 amp and a 3 gang meter socket. It's done all the time.

In fact your situation is simpler you have a 400 amp main protecting the service and have feeder taps.

 

[Elect117]

If you did your part and showed him the existing load and the new load is still suitable for the 400A /320 Meter then I would just tell him you are putting in feeder tap and not call it another service.

Don't call it a service. Call it a feeder. He might think about it differently.

 

[jaggedben]

I agree, as described in the first post it is definitely not a service upgrade.

 

[electrofelon]

How does someone get to be chief electrical inspector of a major city yet be so off base on something basic and about how the code works? Crazy.

 

[Little Bill]

How does someone get to be chief electrical inspector of a major city yet be so off base on something basic and about how the code works? Crazy.

That's what I ask about the city inspector here everytime I have to deal with him.
Example: He wants a bushing on SE connectors. He says because the conductors are #4 and larger!

 

[infinity]

That's what I ask about the city inspector here everytime I have to deal with him.
Example: He wants a bushing on SE connectors. He says because the conductors are #4 and larger!

I wonder if these guys actually read the wording in the codebook. That one is as clear as day in stating that it applies to raceways. I find the same stupidity with inspectors trying to enforce T300.5 for raceways within a concrete deck. Just read the words it's all right there.

 

[Little Bill]

I wonder if these guys actually read the wording in the codebook. That one is as clear as day in stating that it applies to raceways. If find the same stupidity with inspectors trying to enforce T300.5 for raceways within a concrete deck. Just read the words it's all right there.

He won't take the time to read it with you. He just gets mad when you question him on something.

 

[augie47]

Seems every year there are more and more inspectors who make "seat of my pants" calls. It should be mandatory that any rejection should be accompanied by a Code reference.
For residential I had a check list that covered 90% of the potential violations and had the Code reference by each item

 

[charlesaf3]

This neopyhte chief needs some re-education. As mentioned several times the requirement is that it complies with a load calculation nothing more. Also it's not your job to provide a code section that's his job.

While I strongly agree with you, you do realize what kind of life I'd have going forward? I have a firm policy that if inspectors tell me something I disagree with, but will only take me a few hours, it's much better to take those hours to do the thing than it is to take those hours to fight with the inspector. And god only knows how many hours in the future...

 

[charlesaf3]

If you did your part and showed him the existing load and the new load is still suitable for the 400A /320 Meter then I would just tell him you are putting in feeder tap and not call it another service.

Don't call it a service. Call it a feeder. He might think about it differently.

No way I can't call it a service. Gut rehab. If all this stuff was existing I bet there would be no issue, 100 year old houses they accept a lot, they kind of have to.