I’d like to put in a 50A subpanel in the garage w/ 20+ spaces, so I’m looking at a 100A SquareD QO panel. I have 2 main panels in the basement with 200A and 50A main breakers (only the 50A has spaces left and the panel itself is rated for 150A – not sure why they limited it to 50A initially).
My primary question is whether I can swap the 100A main breaker from the new subpanel with the 50A main breaker in the existing main panel (I realize that I’ll have to upgrade the feeder wire but at least I won’t have to buy a 50A main breaker). Or should I just get a 50A main breaker to put into the new 100A panel?
Thanks!
Replies
Is this another quiz?
My guess: um, no?
And one question: How do you have "2 main panels"? Unless you
have two meters (and get two electrical bills), doesn't one of those
panels have to be a subpanel?
There are two feeds coming out of the meter, one to each main. They are right next to each other.
As for swapping the main breakers, its not clear why this wouldn't be allowed. What would be the difference between the main breaker that comes with the panel and a field-replaceable main breaker? I'm guessing that these are the same types of items and thats what I'm trying to confirm.
Duuuuuuuuuuuuuuude!
I don't like the sound of this, so lets stop this thread right here.....
Call an electrician
It sounds like you have a 320 or 400 amp service.
The common way those are wired is to have two "main" pannels side by side. 400 amp pannels are expensive.
For residential you can do what you want to do, but don't forget that you will have to verify or upgrade the feeders to that main pannel. And they need to be the same brand/series.
In commercial/industrial applications you need to watch the interruping capacity of the breakers.
>> And they need to be the same brand/series.
Can you give a little more info on where this rule applies?
God never gives us small ideas.
Sojourners: Christians for Justice and Peace
">> And they need to be the same brand/series.
Can you give a little more info on where this rule applies?"
Approved equipment.
There needs to be a UL approval for that breaker in that panel.
In general it is only that companies breakers that are approved for that brand of panel.
And of course they need to be the same series(type), they just don't physically work.
Now a number of companies have panels and breakers that are "universal". And you can often interchange between them. But, except in a few cases, they are not approved for other brands. And there are small variations between them (no standard spec) and they all combinations of brands of universal breakers won't work with all brands of universal panels.
Ahhh, thanks.
I had thought when you said feeders, you meant the lines running from the meter to the main disconnect.
Very rarely I have seen panels where the two 110 lines were obviously differnt manufacturers. I even saw one a month or so ago where one was alum, the other copper, & there was evidence of prior damage to one of the service lines.
I didn't know if that was permissible (and doubt that it was); but I told my client that as an HI, I'm a generalist; there are times where a speciailist's knowledge needs to be sought, and that was one of them, since I had never seen that before.
I though I had a pic, but can't find it at the moment ....God never gives us small ideas.
Sojourners: Christians for Justice and Peace
Thanks Bill, I think you've described my setup exactly. I do indeed realize that upgrading the 50A main panel to 100A may require a bigger feeder line from the meter (I'd call in a pro to deal with any meter-related work).
I should've mentioned that the two existing panels & the one I want to get are all SquareD QO panels and the SquareD load center brochure lists different "Field Installable Main Breakers", thereby giving me the idea of swapping the new 100A breaker with the 50A one already in one panel.
Thanks again for everyones time & advice.
Pete
Edited 10/17/2004 9:41 pm ET by DB2521
Edited 10/17/2004 9:41 pm ET by DB2521
It would be unlikely you would have a 320/400A meter base with the main panels you describe; usually ther would be two 200A panels. More than likely you have an improperly double tapped meter base (two wires under one lug). That's why the second panel is only 50A - they couldn't fit any bigger wires under the lug. Consult an electrician to evaluate the setup and give you some ideas.
Thanks Normel, I never considered that (though I did wonder why the second panel was only 50A).