Moving from 12/2 to 14/2
Speedy Petey is a pro and I'm just a long-time DIYer, but I think that you're confusing things a bit. Here's a little more detail.
From a DIYer's viewpoint, you need to know what I consider a few DIY "basics",
1. Residential circuits are usually either 120 volts (aka 110v for standard receptacles, lighting and dedicated circuits for smaller appliances such as dishwashers, microwaves, etc.) or 240v (aka 220v for dedicated circuits for heating/ac units, ranges, dryers, water heaters, etc.).
2. The 120v circuits either have 15 amp or 20 amp single-pole circuit breakers, and the 240v circuits have double breakers in varying higher amps. The black (and red if 240v) "hot" wires go on the breakers, and the white (neutral) and bare/green load wires go on the busses, unless its a 120v/240v Ground Fault Circuit Interruption (GFCI) circuit and the neutral load wire also goes on the breaker.
3. A straight 240v circuit, such as for a water heater on a 30 amp breaker, will not have a neutral wire, just two "hots" and a ground. The two water heater "hots" will be 10/2wg, so the white wire will be hot instead of neutral in this case. A 120v/240v circuit, such as for a range or dryer, will have two hots, a neutral and a ground. 240v circuits require 10g or larger wiring, depending upon code for that dedicated circuit.
4. You can put 14g on a 15 amp circuit, but not on a 20 amp circuit breaker. You can put 12g on either a 15 or 20 amp breaker.
Receptacle circuits, depending upon the location, can be on 15 or 20 amp. Lighting circuits are usually 15 amp. I chose to put all 12g in all of my 120v circuits when I built my home, but some are on 15 amp breakers (for lights only) and all others are on 20 amp circuits for receptacles. I don't have any 14g in my home, but that's just my choice, and has nothing to do with code. 14g is just fine for lighting and most circuits.
5. All above-counter receptacle circuits in a kitchen and bathrooms and outdoor receptacles should be GFCI. Theses circuits can either be on a GFCI breaker or have a GFCI receptacle as the first in the circuit and then all standard receptacles after it in the same circuit will be GFCI-protected.
I hope that this explains just some of the basics as a DIYer, and I hope that any of the pros will correct me or clarify the above if I'm wrong. I don't pretend to be a qualified electrician by any means, and I usually consult or hire a pro if I have any doubts, as we all should.
Improper plumbing will just leak. Improper electrical work can kill you or burn your house down. Don't mess with it unless you're certain about how to do it safely.
Last edited by Mike Swearingen; 11-21-2005 at 01:35 AM.