ECN Forum Forums Code Related Discussion NEC & other Code issues 15/20amp Recepts

DANGER

I have herd some crazy things on this subject in the past. It is easy to confuse switches with receptacles here. Switches, the rating is for the device, with receptacles its the face configureation as well as the feed through capacity. All 15A. residential receptacles are 20A. feed through. I have checked this.

I beleive there should be a code change that 20A. face configuration receptacles should only be allowed as a single device circuit as anything that could use that config such as a copier, will be running neer 80% the circuit capacity rendering the rest of he circuit useless and causing an overload hazard. Besides, even in spec grade situations the 15A. spec grade receptacles are cheaper.

There is no requirement that total load on a receptacle circuit be less than 80%, only that a single piece of equipment be less than 80%. The assumption is the user will keep plugging things in till the breaker trips and unplug the clock.
That is the purpose of 240.4(D). It builds the safety factor into the sizing of the O/C device. Compare 240.4(D) to 310.16 and you see it.