Subpanel Sizing

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starsandstripes

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I cannot find this in the code and was looking for opinions/rules of thumb.
Should a subpanel be smaller than the main service panel or can it be the same size? I have a small farmhouse which only needs a 100 amp panel. It will be fed from a service panel in the barn. Should I make the service panel 150 or 200 amp, or can it be the same size as the house?
 
starsandstripes said:
I cannot find this in the code and was looking for opinions/rules of thumb.
Should a subpanel be smaller than the main service panel or can it be the same size? I have a small farmhouse which only needs a 100 amp panel. It will be fed from a service panel in the barn. Should I make the service panel 150 or 200 amp, or can it be the same size as the house?
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The size of the panel is not really relevent. If you have a 100 amp service with a 100 amp panel and sub fed a 60 amp circuit to another panel, then that panel can be 200 amps as long as the calculated load does not exceed 60 amps. It must be properly protected with the correct OCPD for the circuit not the panel.
 
I had this discussion with a guy at the work the other day....he was complaining about the price/locating a 60A sub-panel he wanted to install.
I said, put in a 100A panel with 60A OCPD ...he didn't understand...so I explained....you could put in a 200A panel if you neeeded the space (not amps) on that 60A OCPD. (Dennis...were you talking to same guy ???)

Same here...the size of the panel is irrelevant, the OCPD protecting the panel is the only concern.
 
celtic said:
I had this discussion with a guy at the work the other day....he was complaining about the price/locating a 60A sub-panel he wanted to install.
I said, put in a 100A panel with 60A OCPD ...he didn't understand...so I explained....you could put in a 200A panel if you neeeded the space (not amps) on that 60A OCPD. (Dennis...were you talking to same guy ???)

Same here...the size of the panel is irrelevant, the OCPD protecting the panel is the only concern.
Click to expand...

why would you need to change the OCPD in the subpanel? the 60A feeder would be protected by a CB in the main panel.
 
petersonra said:
why would you need to change the OCPD in the subpanel? the 60A feeder would be protected by a CB in the main panel.
Click to expand...

You (or this fellow I was talking with) don't.

He was under the impression that a 60/100/150/200A panel needed an equal sized OCPD. He needed 60A, and a 100A panel with 60A OCPD fits the bill and, apparently, a 100A panel was easier to locate/cheaper than a 60A.
 
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