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New Sub panel Breaker rules??
- Thread starter W-Cummins
- Start date
pattenp
Well-known member
You shouldn't feed a main lug panel off of feed through lugs in a main breaker panel. A main lug panel needs to be protected upstream by a breaker. I believe a main breaker panel being used as a sub can be fed by the feed through lugs in the main breaker panel. I may not be totally correct on this. I'm sure someone else will chime in.
rabidsquirrel
Well-known member
Don't know about resi, but it's done in commercial all the time. Really ***** when you have to shut off four floors when you want to work safe. The museum really wasn't happy about that.
You shouldn't feed a main lug panel off of feed through lugs in a main breaker panel. A main lug panel needs to be protected upstream by a breaker. I believe a main breaker panel being used as a sub can be fed by the feed through lugs in the main breaker panel. I may not be totally correct on this. I'm sure someone else will chime in.
Do you have a code section for this, or is it just a "good" idea??
Thanks
William......
pattenp
Well-known member
I'm thinking there is a code section that would pertain to this when it comes to means of disconnection and protection. I just can't point to it. I thought someone would have posted something affirming this or not. From my limited knowledge I would think it's a "proper thing to do".
Last edited:
Aceman
Well-known member
You can have as many main lug panels as you want in the same building.
If you use feed through lugs and feed a downstream panel, everything must be rated to meet the OCPD in the first panel. For example, if you have a 200 amp main breaker then your feed through lugs, wire, and main lug panel must all be rated at least 200 amp.
If you use feed through lugs and feed a downstream panel, everything must be rated to meet the OCPD in the first panel. For example, if you have a 200 amp main breaker then your feed through lugs, wire, and main lug panel must all be rated at least 200 amp.
Charles (in GA)
Well-known member
I don't think there is an issue with doing this, you must use the correct size wire for the breaker that protects the main panel. You cannot suddenly downsize the wire coming off the bottom of the main panel, If you have a 200 amp breaker and 4/0 wire feeding the main, you will need to continue 4/0 off the bottom to the sub panel. You don't want a thinner wire that might burn up and not trip the breaker.
I do not know of any code changes, but then again, I'm no expert.
Charles
I do not know of any code changes, but then again, I'm no expert.
Charles
MrMark
Well-known member
Actually, you would need to upsize the wire because the special service entrance table ampacity would not be available. That is if you had branch circuits in your service equipment. Thus, 250 kcmil would be required for 200A aluminum. That is my understanding and if it is wrong I am sure if will be corrected.
pattenp
Well-known member
So my thought of a smaller amp main breaker panel fed by feed through lugs being okay is actually wrong. I was thinking using a main breaker as the sub-panel would meet the protection requirements for the smaller feed. So technically the protection needs to be at the source where the conductors receive their supply.