My understanding is none of the individual appliances would typically draw more than 15 amps. But running two 8 amp appliances would blow your breaker if it were 15 amp and your wiring would get hot if it were only rated for 15 amps.

You'd want a 20 amp outlet if a single device were going to draw more than 15 amps and less than 20. Thou for short durations the 15 amp outlet would work, it does in everybody's house!

I have a 110v 20 amp wire welder in my garage. I wanted versatility in where I used it so I put heavy 20 amp rated outlets in everywhere. Could I get by with 15's, probably, but any lengthy welding project could heat up the 15 amp components quickly.

Here is a follow-up question... Suppose I am building a new house or putting in an addition, aside from cost is there any reason _not_ to put in 20 AMP circuits instead of 15 AMP circuits?

Drawbacks of #12 are pretty much limited to box fill. It is easy to end up with too many conductors in a box if you use #12 wire.

Tom

The reasoning for 15/20 amp receptacles on 15/20 circuits is this. 15a and 20a receptacles have different pin configurations. A 20a receptacle will have one slot that is turned sideways or T shaped to allow a 20amp plug to be used.
A 15amp receptacle on a 20 amp circuit will not overload the circuit. You will only be allowed to plug in 15a devices. How many you plug in is always a concern that you should observe.
However if you put a 20 amp receptacle on a 15 amp it allows a 20 amp device(like an AC) to be plugged into a 15a rated circuit. This is an immedeate problem for the circuit.

[This message has been edited by joed (edited July 15, 2003).]