Originally Posted by
Mike Cutler
Steve
To digress slightly, that configuration, with a 30amp/220 instead of a 20 amp/220, we used to call an "appliance breaker", and it's a pretty expensive item.
If you were renovating and needed to add laundry service, that one breaker met all of the needs. Dryer, washer, and convenience receptacle.It would preclude overloading the neutral return. The models for the high capacity electric ovens and ranges are similar, very expensive also.
Randy
The breakers you are referring to are called "Split", "Mini", and per most electricians, the code, and the literature for a panel, a "Tandem" breaker. There are specific code requirements for their use, installation, and their specific physical location inside the panel is part of the manufacturers design. Panel Manufacturer's will specify which slots, if any, can be used for a tandem application. Some manufacturer's do not allow any use of tandems in their panels, and thus do not make them under their own name.
The box you mentioned has 20 slots and while tandems will save you room, it doesn't mean it will be correct, or code compliant. The box, by design, is only supposed to have a certain number of current carrying conductors. it would be a shame if you got it all loaded up and the building inspector gave you the big thumbs down.
A sub panel in the same building space is a very easy install, and you may find that it will be more cost effective in the end than populating your current panel with tandems. It will also facilitate future expansion.