multiple subpanels??


  #1  
Old 12-08-05, 10:15 PM
sparky69
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multiple subpanels??

i have been a residential electrician for about 7 years, and have been doing commercial electrical work for the last 2 years. i recently ran into a situation that i have not seen before, and can't seem to find an adequate answer in the NEC. this is the scoop: residential 100 amp panel that feeds 2 smaller subpanels. the main panel is older and only has maybe 12 spaces. the 1st sub (main lug) is fed from a 60 amp breaker off the main panel. the 2nd sub (also main lug) is paralleled off the 1st sub. these are both small subpanels rated at 60 amps with maybe 6 breaker spaces each. is the fact that the 1st sub has 2 wires under the main lugs (one from main and one paralleled to the 2nd sub) a code violation? can 2 subpanels be paralleled together this way and fed off 1 breaker legally? all neutrals & grounds are separated in the subs, back to the main as required by code.

i know that the correct way to resolve this problem would be to replace the main panel with one large enough to make the multiple subs unnecessary, but the house in question is being sold and the owner only wants to do the minimum required to meet code.

usually i would have the luxury of asking co-workers or inspectors on the job, but i have been laid off for the last few months. any help on this problem would be appreciated.
 
  #2  
Old 12-09-05, 07:39 AM
J
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is the fact that the 1st sub has 2 wires under the main lugs (one from main and one paralleled to the 2nd sub) a code violation?
Probably. It's unlikely that the lugs are rated for two wires. Check the specs for the specific panel to be sure. Call the panel manufacturer with the model number if necessary. Did the home inspector point this out as a violation, or a possible violation (the home inspector's favority weasel word)?

can 2 subpanels be paralleled together this way and fed off 1 breaker legally?
Yes, but of course they are limited to 60 amps in total.

i know that the correct way to resolve this problem would be to replace the main panel with one large enough to make the multiple subs unnecessary
Not necessarily. There's nothing wrong with subpanels, and they are the best solution for many situations.
 
 

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