mix and match panels

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Ponchik

Ponchik

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Electronologist
I have a commercial customer with CH 200Amp 65K AIC rated main breaker. We need to add another sub next to it for more breaker space. I am wondering if I can do SQUARE-D with 22K AIC rated panel.


  1. Does the 2nd panel have to be CH with 65K AIC rating?
  2. SQUARE-D is OK but has to be 65K AIC rating
  3. SQUARE-D is fine and can be 22K AIC rated, because it will be in series with the main CH breaker that is rated at 65K AIC.

Also, any code issue that you see with this install? I could not find any code sections that I am violating, but I am still searching.
 
Correct answers to Question 1 and 2 can not be verified without your knowing the actual short-circuit-amps-available. You can only assume from the rating of the C-H panel.
As far as question 3, as far as I know, no manufacturer series-rates their equipment with that of another manufacturer.

Your Code references are 110.10 and perhaps 110.22
 
Thanks.
I don't know what the actual rating is but the main breaker is rated at 65K AIC.

I had a feeling that two manufacturers may not be able to be series rated.
 
What are the ratings of the branch breakers in the original panel? If they are also high you have another indication that you need to get an actual available short circuit current calculation.
 
I am not sure but my understanding is, if the main breaker has 65K AIC rating then the branch breakers or any sub panel being fed from that breaker can have a lower AIC rating.
 
edward said:
I am not sure but my understanding is, if the main breaker has 65K AIC rating then the branch breakers or any sub panel being fed from that breaker can have a lower AIC rating.
Click to expand...

not necessarily... within the same manufacturer that is often the case but the ability to "series rate" is dependent on the various factors of both the upstream and downstream breaker.
You can get charts from the manufacturer and you will see a change in style, amperage and even number of poles can make a determination as to the series rating.

Here is a publication from SquareD that might help:
http://static.schneider-electric.us/docs/Electrical Distribution/Switchboards/2700DB9901.pdf
 
edward said:
I am not sure but my understanding is, if the main breaker has 65K AIC rating then the branch breakers or any sub panel being fed from that breaker can have a lower AIC rating.
Click to expand...

They can if you can either do the calculations or use series rated equipment. I can't do the calculations.

One of the factors in the calculations is the length / impedance of the circuit. So a sub-panel a 100' from the main panel could have lower AIC rating than a sub-panel right beside the main panel.
 
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