# 400A service with 2x200A panels



## JupoiUrzici

Does NEC allow 2-200 amp service panels to be wired from the same meter base in a residence? The service size will be 400A.

I have one 2 x 2" conduits running from the meter base to the house, each conduit having 1 set of 3/0 wires. The 2 electrical panels will be installed at the conduit's point of entry in the house, within 2 feet of each other. I know I'm allowed to have up to 6 individual disconnects (panels) if they are in the same location (230.40, exception 2).

FYI, this is in Chicago. Chicago adopted NEC 2017, with amendments. From what I've checked, I couldn't find an amendment against it.

The reason I'm asking this is that I've called an electrical supplier to give me a quote, and the guy said it is illegal in Chicago to have 2 200A panels individually fed from one 400A service. I asked them to give me the article that says that, but he didn't know.

I've also called two city inspectors, and one said yes (if I respect the tap rules?), while the other one said no, because I don't have a single point of disconnect.

Am I missing something here?

Thank you


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## Bird dog

Ask your Jman. Who pulled the permit? This will need to be inspected.


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## frenchelectrican

It useally pretty common to see 400 amp residential service and I have no issue with it as long the meter is rated at 400 amp max or Class 320 system in there and with two hole lug .,, that is common.

and two 200 amp panels that is common as well due it cheaper than order a large single 400 amp panel and put a subpanel next to it. 

Please check with Chicago POCO specs reguarding of 400 amp residential service and read the FPN if they have it especially with 208 volt network system and dont be too surprised if the inspector want to see the load demand caluation so expect that.


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## Southeast Power

I have installed a few meter main combos with two 200 amp breakers in them.
Are you trying to not install the main disconnects "grouped"???


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## A Little Short

If you're pretty much going back to back from the meter to the panels then you shouldn't need any disconnects. If the distance is too far or farther than your AHJ allows then you would need a disconnect(s). The meter base (320A) will have dual lugs so you can feed either the panels or disconnect(s).


I've done a few of these and never had a problem. Can't answer for Chicago though.


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## JupoiUrzici

frenchelectrican said:


> It useally pretty common to see 400 amp residential service and I have no issue with it as long the meter is rated at 400 amp max or Class 320 system in there and with two hole lug .,, that is common.
> 
> and two 200 amp panels that is common as well due it cheaper than order a large single 400 amp panel and put a subpanel next to it.


Indeed the meter is rated at 400A, with 2 hole lug.



frenchelectrican said:


> Please check with Chicago POCO specs reguarding of 400 amp residential service and read the FPN if they have it especially with 208 volt network system and dont be too surprised if the inspector want to see the load demand caluation so expect that.


Comed is the energy supplier in the area where the service will be installed. I've tried searching for some info, and I came across Comed Service and Meter requirements (can't link, post count not enough). I skimmed trough it, but nothing stood out.

I will probably end up calling another inspector, and try to see exactly what the deal is. What really bugs me is that one inspector said yes, while the 2nd one said no. If both would have given me the same answer (whether yes or no), I would've said c'est la vie, and moved on.



Southeast Power said:


> I have installed a few meter main combos with two 200 amp breakers in them.
> Are you trying to not install the main disconnects "grouped"???


The panels will be in the same room, on the same wall, 2ft of each other.


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## JupoiUrzici

Bird dog said:


> Ask your Jman. Who pulled the permit? This will need to be inspected.


My Jman suggested we do the work this way with 2X200A panels, instead of one 400A panel and one 200A subpanel. That's why we roughed in 2x2" conduit, instead of one 4".

The work will be inspected, but I would hate to have to rip everything out because Chicago doesn't allow this sort of installation.

Chicago made huge changes to the electrical code last year, by adopting NEC 2017( with amendments). Until March 2018, I believe it hadn't been changed since 2003.


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## MikeFL

A Little Short said:


> If you're pretty much going back to back from the meter to the panels then you shouldn't need any disconnects. If the distance is too far or farther than your AHJ allows then you would need a disconnect(s). The meter base (320A) will have dual lugs so you can feed either the panels or disconnect(s).
> 
> 
> I've done a few of these and never had a problem. Can't answer for Chicago though.


I always understood Chicago wants outside disconnect for all services (for the fire dept).


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## Southeast Power

JupoiUrzici said:


> Indeed the meter is rated at 400A, with 2 hole lug.
> 
> 
> 
> Comed is the energy supplier in the area where the service will be installed. I've tried searching for some info, and I came across Comed Service and Meter requirements (can't link, post count not enough). I skimmed trough it, but nothing stood out.
> 
> I will probably end up calling another inspector, and try to see exactly what the deal is. What really bugs me is that one inspector said yes, while the 2nd one said no. If both would have given me the same answer (whether yes or no), I would've said c'est la vie, and moved on.
> 
> 
> 
> The panels will be in the same room, on the same wall, 2ft of each other.


If you are going to do it, be ready to sell the installation to the inspector if 100 years of past practice has a disconnect on the outside.
If you have a strong Fire Department, they might have some kind of ordinance in place that requires and exterior disconnect. 
Just to CYA, order the breakers with a shunt trip. That might save your boss a complete do over.


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## Dennis Alwon

Do I understand this correctly that you have a meter that is remote from the house? If so then the only problem may be that you need a disconnect outside. If chicago has that rule, I doubt they do, then it is an issue, othersise it is fine.

I think the inspector who said NO was thinking you had a disconnect at the meter. In this case you would not be compliant with 2 runs to the house.


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## sbrn33

Dennis Alwon said:


> Do I understand this correctly that you have a meter that is remote from the house? If so then the only problem may be that you need a disconnect outside.


Maybe in Chicago but the NEC does not require that.


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## MikeFL

Holy cow the NFPA has a publication called NFPA 70: National Electrical Code with Chicago Amendments


https://catalog.nfpa.org/NFPA-70-National-Electrical-Code-with-Chicago-Amendments-P18112.aspx


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## JupoiUrzici

I called Chicago Department of Buildings earlier and I had a chat with the supervising electrical inspector. The gist of our conversation was that I'm not allowed to do 2X200A panels, because wait for it...... is considered complicated wiring (pfff). I referenced 230.40 (exception 2), and he said that exception 2 is not intended for single family homes, but for multifamily dwellings, even though that is not specifically stated in the exception. I asked for an article that prohibits me to have 2 panels, and got pointed to 110 section (he couldn't reference the exact article).

At this point, based on the answers I've been getting from inspectors, I feel Chicago inspectors don't like this sort of installation, without having a good (code backed) reason for it.

I find myself in a pickle now, because I feel the code is on my side, but also I don't want/need beef with electrical inspectors.


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## CoolWill

It doesn't appear that ComEd requires an exterior disconnect:
https://www.comed.com/SiteCollectionDocuments/service_and_meter_requirements.pdf


Of course, you need to check with the city code.


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## frenchelectrican

JupoiUrzici said:


> I called Chicago Department of Buildings earlier and I had a chat with the supervising electrical inspector. The gist of our conversation was that I'm not allowed to do 2X200A panels, because wait for it...... is considered complicated wiring (pfff). I referenced 230.40 (exception 2), and he said that exception 2 is not intended for single family homes, but for multifamily dwellings, even though that is not specifically stated in the exception. I asked for an article that prohibits me to have 2 panels, and got pointed to 110 section (he couldn't reference the exact article).
> 
> At this point, based on the answers I've been getting from inspectors, I feel Chicago inspectors don't like this sort of installation, without having a good (code backed) reason for it.
> 
> I find myself in a pickle now, because I feel the code is on my side, but also I don't want/need beef with electrical inspectors.


Did those inspectors ever show the paper what it stated in their code ?


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## MikeFL

frenchelectrican said:


> Did those inspectors ever show the paper what it stated in their code ?


Sounds like they're saying "that's not what it says but this is what it means...".

OP doesn't want to battle the city. Can't blame him. Find out how they want it done and do that. Everyone goes home smiling.


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## CoolWill

I find that if you go asking an inspector before the job, he will find something to say to the contrary. Instead, know the letter of the code and any amendments, know the utility requirements and just do the job. If it is to code and meets all specs, they have nothing to argue.


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## JupoiUrzici

At this point we've decided to not take any risks and do the job the way the inspectors want it done. One 400A main panel and a 200A sub-panel. 

I will not give up so easily on this issue though. Plan on revising the new Chicago code some more, an then send an email to the Chicago Department of Buildings, asking for clarifications.

Will update once I have a reply.


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## Kevin

A 400 amp panel is much more expensive than a 400 amp fusible disconnect, a splitter, and 2-200 amp panels. That's how almost all 400 amp services are done around these parts. might be worth pricing out.

pipe into the disco, pipe out of there to the splitter. then pipe outta there to the 2 panels (usually mounted right above the splitter)


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## RichardW66

JupoiUrzici said:


> Does NEC allow 2-200 amp service panels to be wired from the same meter base in a residence? The service size will be 400A.
> 
> I have one 2 x 2" conduits running from the meter base to house, each conduit having 1 set of 3/0 wires. The 2 electrical panels will be installed at the conduit's point of entry in the house, within 2 feet of each other. I know I'm allowed to have up to 6 individual disconnects (panels) if they are in the same location (230.40, exception 2).
> 
> FYI, this is in Chicago. Chicago adopted NEC 2017, with amendments. From what I've checked, I couldn't find an amendment against it.
> 
> The reason I'm asking this is because I've called an electrical supplier to give me a quote, and the guy said it is illegal in Chicago to have 2 200A panels individually fed from one 400A service. I asked to give me the article that says that, but he didn't know.
> 
> I've also called two city inspectors, and one said yes (if I respect the tap rules?), while the other one said no, because I don't have a single point of disconnect.
> 
> Am I missing something here?
> 
> Thank you





JupoiUrzici said:


> Does NEC allow 2-200 amp service panels to be wired from the same meter base in a residence? The service size will be 400A.
> 
> I have one 2 x 2" conduits running from the meter base to house, each conduit having 1 set of 3/0 wires. The 2 electrical panels will be installed at the conduit's point of entry in the house, within 2 feet of each other. I know I'm allowed to have up to 6 individual disconnects (panels) if they are in the same location (230.40, exception 2).
> 
> FYI, this is in Chicago. Chicago adopted NEC 2017, with amendments. From what I've checked, I couldn't find an amendment against it.
> 
> The reason I'm asking this is because I've called an electrical supplier to give me a quote, and the guy said it is illegal in Chicago to have 2 200A panels individually fed from one 400A service. I asked to give me the article that says that, but he didn't know.
> 
> I've also called two city inspectors, and one said yes (if I respect the tap rules?), while the other one said no, because I don't have a single point of disconnect.
> 
> Am I missing something here?
> 
> Thank you


I’m in Tallahassee, Florida, in Leon County, so this may not be of any assistance considering the maintaining authority has the final say regardless of the NEC.
I’ve installed several 400A residential services. 
Leon County requires a 400A meter base(2 parallel sets of feeders, 3/0 copper or 4/0 aluminum), with 2-200A main breakers serving 2-200A MLO panels. 
The City of Tallahassee requires a 400A meter base with internal 400A breaker/means of disconnect, with 500MCM cable feeding panel 1 with double lugs to feed through to panel 2, both panels with 200A mains.
Cost should never be a factor. You bid the job, do the job according to your local governing authority. The NEC only dictates minimum installation practices and is always superseded by the local authority as long as it meets or exceeds the NEC. 
There’s always enough time and money to do it right, never enough to do it twice.


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## Dennis Alwon

You do realize this thread is almost 3 year old.


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## RichardW66

Dennis Alwon said:


> You do realize this thread is almost 3 year old.


Hey thanks my guy. Yes, I do, but my two cents is free and never expires. 
Wire on my friend!


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## Dennis Alwon

RichardW66 said:


> Hey thanks my guy. Yes, I do, but my two cents is free and never expires.
> Wire on my friend!



It is fine but when you quote someone you may be expecting them to see it and often times, as in this case, those members are no longer participating. Just making sure you understood.


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## hornetd

Dennis Alwon said:


> I think the inspector who said NO was thinking you had a disconnect at the meter. In this case you would not be compliant with 2 runs to the house.


Dennis 
Why would a disconnect at the meter make having 2 separate conduit runs to the panels unacceptable? The 3/0 copper service entry or feeder conductors are 225 Ampere ampacity. Are you referring to those conductors being Feeders and requiring Equipment Grounding Conductors if there is a disconnect at the meter? 

-- 
Tom Horne


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## hornetd

CoolWill said:


> I find that if you go asking an inspector before the job, he will find something to say to the contrary. Instead, know the letter of the code and any amendments, know the utility requirements and just do the job. If it is to code and meets all specs, they have nothing to argue.


If you always do that how many times have you had to go to some sort of formal appeals process? How many times did you have to make the changes that the inspector ordered. That sort of stuff can get expensive real quick! 

Tom Horne


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## Dennis Alwon

hornetd said:


> Dennis
> Why would a disconnect at the meter make having 2 separate conduit runs to the panels unacceptable? The 3/0 copper service entry or feeder conductors are 225 Ampere ampacity. Are you referring to those conductors being Feeders and requiring Equipment Grounding Conductors if there is a disconnect at the meter?
> 
> --
> Tom Horne



The situation I am talking about is when you have a remote meter with a service disconnect at a remote location. Now, anything that you run from there would be called feeders.

Then article 225.30 states



> Part II. Buildings or Other Structures Supplied by a Feeder(s)
> or Branch Circuit(s)
> 225.30 Number of Supplies. A building or other structure
> that is served by a branch circuit or feeder on the load side of a
> service disconnecting means *shall be supplied by only one
> feeder or branch circuit* unless permitted in 225.30(A)
> through (E). For the purpose of this section, a multiwire
> branch circuit shall be considered a single circuit.


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## hornetd

Dennis Alwon said:


> The situation I am talking about is when you have a remote meter with a service disconnect at a remote location. Now, anything that you run from there would be called feeders.
> 
> Then article 225.30 states
> Part II. Buildings or Other Structures Supplied by a Feeder(s)
> or Branch Circuit(s)
> 225.30 Number of Supplies. A building or other structure
> that is served by a branch circuit or feeder on the load side of a
> service disconnecting means *shall be supplied by only one
> feeder or branch circuit* unless permitted in 225.30(A)
> through (E). For the purpose of this section, a multiwire
> branch circuit shall be considered a single circuit.


Dennis

That was a good catch. I completely forgot to apply that rule. If it can be done to be US National Electric Code compliant the suggestion that I'm making to convert the 2 sets of 3/0 conductors to parallel sets of conductors for the same feeder could be even more useful even though I didn't get the impression that the inspector called them on that. The Inspector's concern seemed to be limited to the ampacity of the feeders.

-- 
Tom Horne


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