We moved into a resale home, the previous owners had a Gas Dryer, we have an Electric. The laundry room has a NEMA 14-30 receptacle installed. I hooked up our brand new dryer and it didn't get power.

Went to the Panel and checked the breaker, 30AMP Double Pole, everything checked out. Dig out my voltage meter and didn't get any reading from the receptacle. Head down to the panel and test there, reads 120V. Do some reading tells me I should have 2 hot wires both 120V to make 240V, head back to the receptacle and removed it from the wall to make sure I am getting good contact, still zero volts. Head back to the panel, this time I realize that there is only one wire going to the breaker and it's not as thick as the 3 wires upstairs, I then see a red and black with marrets on them tucked in the back that look to be the same thickness as upstairs.

Hmmm odd, I flip the breaker off and head upstairs to see if I can find out what is connected to the breaker, but I can't see anything that doesn't have power. Head back down to the panel and I removed the single red from the 30AMP Dual breaker and connected the thicker Red to the top and the Black to the lower. Flip the breaker back on and test the voltage, both reading 120V, head back upstairs and test the receptacle, reading 240V.

Connect the dryer and viola we have power!

So two questions really:

  1. Is the wiring of the NEMA 14-30 done correctly? Red/Black went to the 30AMP Dual Pole Breaker, White went to Neutral, and Ground went to ground.
  2. How do I find out where the other wire went, I mean it was a single connection to a 30AMP Dual which was marked on the panel as Dryer?

4 Answers 4

  1. Yes, you wired the NEMA 14-30 receptacle correctly. That receptacle has two hot connections, each 120V but on different phases, resulting in a 240V potential. So if you take a voltage tester you will find it reads 240V between the two rectangular slots on the outlet, and 120V between either rectangle and the neutral or ground. You can check this using your voltage tester, but it sounds like you did it correctly.

  2. Figuring out where that wire went is going to be tricky. If you can't find it visually or by process of elimination, the best tool to help would be a tone & probe kit. You'd hook up the tone generator to your mystery wire (after double-checking that it's not live) and take the probe component with you. When the probe is near the toned wire, it will beep, even if it's a few inches away inside a wall.


I bet there's a standard 15- or 20-amp outlet nearby that the previous owners used to power their gas dryer, that, before your fix, was powered by the red wire that had been attached to one pole of the breaker.

As a side benefit to fixing this you've also made your home safer: using a 30-amp breaker to supply current to a 15- or 20-amp circuit is a major fire hazard.

  • 2
    That's a good guess - it's the kind of rule-breaking that I'd expect to see.
    – Jay Bazuzi
    Jan 27, 2011 at 18:37

Sounds in your description the actual recpt is wired properly. If you think the similar wires hanging unconnected in your breaker panel are the ends of said recpt , there is an easy way to test them. First, be absolutely sure there is no voltage on the wires in the panel. Simply short the red and black, then put your ohm meter or continuity checker on the red and black in the recpt. Do the same with the white and bare ground. If the ohm meter reads 0 ohms, or the continuity checker beeps, then you have found the correct wires. If they don't, you will have some more investigating to do. Now it is simple to connect the white and bare grounds to the ground buss, and the red and black to the two terminals on the double pole 30 amp breaker. Be sure breaker is turned off or remove it from voltage buss before connecting the wires. After this is done, recheck your voltage at recpt. You must also find out where the wire that is currently connected to one leg of the breaker is going, and relocate it to a separate breaker the corresponds to the wire size and load. If it is less than a size 10 AWG it is not rated for 30 amps and should not be where it is. Also remember, double tapping (putting more than one wire into a breaker lug) is a code violation and a "NO NO". Good luck.


To find the "loose" wire a tone generator/probe is very handy. This is the least expensive I could find with a quick google. These are easy to use but must !! not!! be connected to a live circuit, since the wire is disconnected at the panel all you would need to do is meter at the panel from wire to ground with a volt meter to be sure it isn't back feeding from somewhere.


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