My 125A Square D HomeLine will not accept tandem breakers

brons2 · 11-01-2010, 02:16 AM

I have recently gotten back to work on my project. I have about finished roughing in the wiring. I had planned to run about 28 circuits in my 24 slot HomeLine main panel by the usage of some tandem breakers.

Come to find out that the tandem breakers would not go in. I took them back to HD and tried them on a 200A HomeLine panel they had for sale there. The area where the breakers snapped in was different on the 200A panel.

So now I'm at a conundrum. Should I try to pare down the number of circuits, or put in a bigger box. What does the power company need to do in order to upgrade my service to 200A? Obviously, I will have to hire a professional electrician as the head city inspector has told me that he will not allow homeowners to make changes to anything on the city side of the main breaker.

Money is a big issue on this project...but if this can be done somewhat economically then I may want to go ahead and upgrade the service along with a bigger main panel. But if it's going to be $5K then forget it, I don't have that much to spend on a diversion of this magnitude.

nap · 11-01-2010, 02:24 AM

If you need the circuit count, you need the circuit count. That is something you will need to decide.

if money is an object, you can install something like a 200 amp MLO (main lug only) panel and backfeed the panel with whatever size breaker your current service is. Make sure the panel is rated as service equipment. That way, you would not be changing anything on the city side of the main breaker.
You can even use a 200 amp MB (main breaker) panel and just not use the main breaker but backfeed with the smaller breaker. Just be sure, in either case, that you put the "service disconnect" sticker by the appropriate breaker.

It would also allow you to eventually upsize to a 200 amp service in the future using the panel you already have.

Even less expensive (generally) is installing a sub-panel.

joed · 11-01-2010, 08:32 AM

Install a sub panel.

md2lgyk · 11-01-2010, 12:49 PM

There should be a sticker on you panel somewhere that lists the breakers that are approved for it. Some panels are not approved for any tandems, while others are approved but only in specific slots.