How many subpanels can be fed from one disconnect?

charlesaf3

Member
Location
Richmond VA
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
I would love that. He actually said he couldn't think of a code reference prohibiting it, but wouldn't accept it unless I cold provide a code ref specifically allowing it.
 

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician

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)
Tell him to go to the local hospital and count up the number of normal branch panels fed from the Normal Power Main disconnecting device.

He can also do it with the other branches.
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
I would love that. He actually said he couldn't think of a code reference prohibiting it, but wouldn't accept it unless I cold provide a code ref specifically allowing it.
You have to pick your battles, if it’s nothing major, you change it and go on. I had an inspector illegally require a neutral/ground bond on the load side of a groundfault protected transferswitch. He was stead fast on wanting it, so I did it, then changed it back after he left. I would have been hung with the responsibility when the ground fault switches didn’t work because of it.
 

winnie

Senior Member
Location
Springfield, MA, USA
Occupation
Electric motor research
Perhaps say to the inspector that they are somewhat correct. You reviewed the code and found that you are not permitted to have more than 400A of calculated load on that 400A service disconnect. (Also not more then 320A continuous...)

Then show the code references.

Then show your calculations with all three feeders. Show that you don't exceed the code mandated limits, and that the inspector pointed out those limits and you did the calculation in response.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Yeah, that's our take. Exactly my thought on the breakers. But he needs a code section..
Charles, I'm in Richmond (Henrico), too, for decades. Most of the inspectors I knew by name are gone.

He needs a code section to say you're not in compliance with.
 

Eddie702

Licensed Electrician
Location
Western Massachusetts
Occupation
Electrician
In MA the inspector if he finds a violation is supposed to give it to you in writing and specify what code section was violated. Still, it is seldom done. I had one written violation in 46 years.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
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...
I'm sorry, but my position is exactly the opposite. I won't kowtow to a bad call even if it will only cost me a few minutes . . . this time. It sets a bad precedent and almost guarantees that the same thing will happen again, which costs us more time and money.

I have formally challenged a fail four times, and "won" every time. It has always been a civil discussion because I remain firm, but I don't get emotional. Most recently, I converted a 200a service to 320a and added a second 200a panel for a tankless water heater.

I ran SE instead of SER, and the inspector failed it because I ran no neutral. He called Dave Humphreys, who knows me, and Dave agreed with him. While telling the inspector that I intend to appeal, Dave called him back and said that I was correct, and to pass it.

I have the attitude that we and the inspectors have a common goal: a safe, compliant, and properly-performing installation. But I let them know that I know the code and that I will not be bullied into obeying the demands of someone who knows less than I do.
 

kwired

Electron manager
Location
NE Nebraska
Yeah, that's our take. Exactly my thought on the breakers. But he needs a code section..
Actually he needs to find a code section that supports what he is claiming. There is nothing that limits number of circuits/feeders that can be supplied by an overcurrent device it only has to be able to handle the load connected to it and can factor in demand or other time of use situations as well if those things end up assuring total demand at any point in time is low enough the device can take it.
 

kwired

Electron manager
Location
NE Nebraska
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...
So you spend all this time learning theory, code and other aspects of electrical are required to pass a test to get a license then most usually need to take certain amount of continued education to be able to keep said license, but an ignorant inspector can basically make all that somewhat meaningless because he doesn't want to learn what is right and just hide behind his authority?
 

kwired

Electron manager
Location
NE Nebraska
I would love that. He actually said he couldn't think of a code reference prohibiting it, but wouldn't accept it unless I cold provide a code ref specifically allowing it.
Most places if he isn't going to pass it, he needs to write up some kind of notice stating what the deficiencies are and provide references to the code or local rules that make it a deficiency. How is he going to do that if he doesn't even know if it is a deficiency?

Is one thing to ask you to change something in the field, but if you resist he will eventually need to write something up that states why he did not pass it.

If something rather minor that really doesn't effect safety maybe not worth the fight, but you need to know which battles are worth fighting or at very least still give him your interpretation of what the rules say even if you are going to give in, maybe if enough people disagree with him on some particular subject he will eventually get the hint and do some more research on it and change his mind.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
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...

My usual strategy in that situation is to do both. Push back and argue politely while still making the correction. Allows them to save face on the current permit but discourages them from asking for the same unfounded correction in the future. Acknowledges their authority while reminding them there are limits to it. Results can be hard to guage in the short term but in aggregate it seems to work over time.
 

david

Senior Member
Location
Pennsylvania
Discussion with chief inspector (city of Richmond VA, TJ if you are here, not Tab, he's gone)
You could present him with 230.40 exception #3 and show him had you douple luged the load side of a 400 amp meter you would not have even needed overcurrent protection at all as far as the load was concerned and you would have been able to supply the garage with a 3 wire service entrance as well as the house with a 3 wire service entrance.

Than you could go to 230.80 where it talks about the combined rating of disconnects. Emphasis on the text saying not less than, meaning it could be greater than or equal to, but just can't be less than.

Than show him 225.39 where it has the same language for feeders as it does services when combining the rating of the feeder disconnects.

By showing him for both services and feeders the code allows it and considers it safe, he will except it as safe. (Hopefully)!

But it's all going to depend on the size feeder you ran
 

Eddie702

Licensed Electrician
Location
Western Massachusetts
Occupation
Electrician
My usual strategy in that situation is to do both. Push back and argue politely while still making the correction. Allows them to save face on the current permit but discourages them from asking for the same unfounded correction in the future. Acknowledges their authority while reminding them there are limits to it. Results can be hard to guage in the short term but in aggregate it seems to work over time.
That was always my approach and it usually worked. You have to know the code. If the inspector doesn't think you know what you're doing they will lean on you harder.
 
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