Re: Circuit Breaker Types
On the label on the door of the panel, it will list the "types" of breakers that are allowed (QO, QD, etc.). As long as the breaker you install is also labeled with one of the same type designations as is listed on the panel -- even if they are different brands -- everything will be OK and the inspector should be happy.
That said, there are several different brands of breakers that are more or less interchangeable, being of the same physical size and shape (Siemens, Eaton, Square D Homeline, Cutler Hammer, ITE, etc.). Practically, there should be no problem mixing brands. However, each manufacturer seems to use their own type codes, and very few inspectors will approve an installation where the type codes on the breaker don't match what's listed on the panel, even if the breakers are identical.
Note that there have been some mergers and buyouts over the past several years, so most new Eaton breakers will match Cutler Hammer panels, Siemens will match ITE, etc.
I pity the poor person who has an old Zinsco or Pushmatic load center. Replacement breakers are only available from a third-party manufacturer, and they are hideously expensive: a single breaker can cost as much as a whole new load center.
Note that for the common "interchangeable" breakers, there are two types of bus contacts in the panels: solid, and ones with a notch. In new installation, "duplex" breakers (that is, two 1/2" wide breakers in a single case) can only be installed on the notched buses. Duplex breakers to fit un-notched buses can be purchased, but they are labeled "for replacement use only."
Last edited by Fencepost; 10-04-2012 at 02:17 AM.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.