Can you plug a four-prong dryer into a three-prong outlet or is there an adapter you should use?

Old practice [accepted by National Electrical Code requirements] allowed the frame [chassis] of dryer to be bonded to the neutral conductor by a link to provide ground. New NEC requirements call for separation of neutral and ground paths. In a new house, or if you install a new cable to feed the dryer, you would be required to run a wire with an insulated neutral and a ground wire [10/3 with ground - 4 wires]

There are 2 possibilities:

One is that there is actually a 4-wire cable feeding that outlet, in which case you CAN change the dryer outlet to a 4 wire type - you just have to put the right wires on the right terminals and make sure the ground is connected in the panel. [Even though we only used 3 wire outlets, most electricians I know had run 10/3 with a ground for dryers in case the unit got hard-wired, which used to be allowed.]

The second possible answer is that you are allowed [unless your township or city doesn't allow it - always check with them first] to establish a ground-to-neutral link inside the dryer unit for the chassis ground and replace the 4-wire plug with a 3-wire plug. [See NEC Article 250.140]

Answer

Some dryers also have devices (such as lights and the timer) that run on 120 volts. These need a neutral that is separate from the protective ground.

Similar Question

I got a new dryer yesterday... the plug on it has four prongs and my old one has three prongs. So can the old three prong plug be taken off my old dryer and be put onto the new dryer? I notice my old three prong plug is not color coded like the one on the new one. Also when I took the old dryer off and unplugged it, a green ground wire was still fixed to it (the old dryer), so how would I ground the new dryer being that it only has three prongs? Thanks in advance.

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You could ground it in the same way as the old dryer was grounded, by fixing the green ground wire to it. [Or, in the old days, you wouldn't ground it, you would have connected the chassis of the new dryer to the neutral wire. (Unless your township or city doesn't allow it - always check with them first.) That's the danger in using the old 3-prong plug: if there is ever a voltage between the neutral and ground, you can get shocked. So don't do that!]

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There is a good chance that wiring is already in place for a 4-prong plug. Even though the present 3-hole outlet doesn't have a ground lug, there may still be a ground wire in the box - it is probably just connected to the box. If you find there is already such a ground wire in the box, along with a separate neutral wire, replace the outlet to a new 4-hole type . It will be then be safer and meet modern code, and you can just plug your new dryer's 4-pin plug into it.

First answer by Robertwilberelectrical.com. Last edit by MidiMagic. Contributor trust: 27 [recommend contributor]. Question popularity: 34 [recommend question].