Bobbo wrote:
DrewE wrote:
Edit: Just noticed the 20A outlet there. Is that on the same 30A circuit (without a 15 or 20A breaker protecting it)? If so, that's definitely not up to code and a bit of a concern; the receptacle is underrated for the circuit's ampacity.
My S&B house has a bunch of 15 amp outlets on a 20 amp breaker. The receptacles are undersized for the circuit's ampacity too. As long as the wires going to the 20 amp outlet are sized for 30 amps, I wouldn't loose sleep over it.
Code specifically permits multiple 15A receptacles on a 20A circuit as an exception to the otherwise inflexible rule that the receptacle can't be rated for less than the circuit's overcurrent protection (for general-purpose circuits--there are probably some other exceptions for odd industrial sorts of things). I presume one reason why this is permitted is because the contacts for 15A and 20A plugs and sockets are internally the same size, with the 20A having one prong rotated 90 degrees. Most 20A sockets are 15A/20A combo sockets (with a T shaped slot), and 20A plugs are pretty uncommon.
The wires to the socket may be 10 gauge (sized for 30A loads), but the wires on the cords plugged into it are almost certainly not sized for that load. It's not as though it's going to explode imminently, but there is the potential for accidentally creating a hazardous situation if one isn't careful and plugs too much in at once (particularly using undersized extension cords or similar).
I'm also not a big fan of the 30A male to 15A female adapters that are available, partly because I've seen at least one case where one of those adapters, and the reverse 15A male to 30A female, were used with an ordinary (probably 16 gauge?) extension cord to power a 30A RV.
