Re: Newby service panel question.
Your QO panel may not be able to accommodate "split" breakers.
Look at the rail that the breakers clip to -- it's the rail under where the wires attach. If the rail has slots underneath it, the split breakers (aka "tandem") will work; if it is solid all the way to the back of the panel they will not work. You'll have to look thoroughly; it may be that only some of the breaker spaces will accommodate tandem breakers.
Tandem breakers are not any less safe than regular breakers. The difference is that some panels have a maximum number of circuits that can be installed (known as "Class CTL" and usually limited to 40 circuits). Tandem breakers can usually only be installed in Class CTL panels. As a rule of thumb, any panel that has 40 spaces will not accommodate tandem breakers; a panel with 30 spaces may accommodate 10 tandem breakers, and a panel with 20 spaces may accommodate 20 tandem breakers (total 40 in each case).
Last edited by Fencepost; 06-09-2011 at 09:42 PM.
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.