Tap from main panel into an enclosed breaker? Panel does not allow breaker size.

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Cartoon1

Cartoon1

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Florida
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Electrical Engineer
I have a 400Amp single phase main panel that is feeding multiple buildings. One of the buildings is being renovated and it requires a 200amp breaker. The current panel does not support a 200 amp breaker (it supported a maximum 150 breaker). The manufacturer of the panel (square d) rep recommended adding an enclosed breaker outside the panel and taping into the main panel lugs. I presume the tap will be after the 400amp main breaker. I do not see any code issues or setup issues with this installation, I wanted to ask here if there are issues I might not be aware of.

Thank you
 
You can add the main and feed the existing panel and your new 200 amp breaker.
Depending on the specifics of the existing panel you might be able to add a 200 amp feed thru lug kit and then feed your breaker..
Can you provide details on the existing panel ?
 
augie47 said:
You can add the main and feed the existing panel and your new 200 amp breaker.
Depending on the specifics of the existing panel you might be able to add a 200 amp feed thru lug kit and then feed your breaker..
Can you provide details on the existing panel ?
Click to expand...
The main panel (also the panel that is feeding the campus mini buildings) is nqod30l400. The renovated building will get a new panel. The enclosed breaker will be by the 400amp main canpus panel to feed the renovated building new panel. Presuming this is the way I go
 
Delivery might be a nightmare but if you are replacing the panel in the building you should be able to obtain one with a 200 amp sub-feed breaker by manufacturer. The key is calling it a "sub-feed breaker" rather than a branch.
Otherwise your plan seems compliant but you need to make sure you added main has the proper lugs for 2 load connections,.
 
augie47 said:
Delivery might be a nightmare but if you are replacing the panel in the building you should be able to obtain one with a 200 amp sub-feed breaker by manufacturer. The key is calling it a "sub-feed breaker" rather than a branch.
Otherwise your plan seems compliant but you need to make sure you added main has the proper lugs for 2 load connections,.
Click to expand...
Sorry I don't completely follow. You mean add the enclosed breaker with its kit and tap into the 400amp panel lugs. Then run cable from the enclosed breaker to the renovated building (about 50 feet away) and the new panel that is going to be added there to have a 200 mcb being fed from the enclosed breaker. Maybe I'm overthinking this, thanks
 
If your existing Square D panel contains an integral 400A main breaker I don't see any way for you to add provisions to connect to an external 200A breaker, without changing the existing back box and panel front. I am not aware of any way to connect subfeed lugs between the main breaker and the panel bussing.
The subfeed lug kit shown in post #6 is for use with main lug panels.
 
I'll bow to Jim's vast knowledge of panelboards. I have used load side sub-feed lug kits before but never on a NQOD and was apparently mistaken in their availability.
 
jim dungar said:
If your existing Square D panel contains an integral 400A main breaker I don't see any way for you to add provisions to connect to an external 200A breaker, without changing the existing back box and panel front. I am not aware of any way to connect subfeed lugs between the main breaker and the panel bussing.
The subfeed lug kit shown in post #6 is for use with main lug panels.
Click to expand...

hmmm, can i tap before the main circuit breaker? I do not want to replace the whole panel to provide a 200A breaker. Is there other solutions? attached is a pic of the panel. meter on the right side of the panel
 

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Read the tap rules in 240. From your picture one can't tell if the conductors on the line side of the main are service conductors or not. But either way, I think you are safe with the tap. In fact as long as the conductors stay outside, you may not even need to mount a breaker on that building. Outside taps are unlimited in length. Like many things in the code, there could be several different codes that affect the installation, in this case, possibly 230 services, 225 I think is underground feeders where required disconnecting means are, 240 overcurrent protection where the tap rules are.
 
Maybe you could use (2) 100A plugin sub feed lug kits to feed parallel conductors to your 200A breaker? I haven't given it any deeper thought than typing this post.
 
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