Live ground wire in dryer

12279 Views 10 Replies 10 Participants Last post by Ultrarunner2017, May 4, 2009

Retired sailor

Discussion Starter · Apr 30, 2009

I am connecting a 4-wire cord to a dryer which use to have a 3-wire cord. I've wired the dryer according to instructions - white/neutral to center; black and red to side terminals, and green ground to ground terminal without success.

When the old 3-wire was connected, there was a green wire coming out of the dryer (internal) and connected to the ground terminal. When this green wire was connected to the ground terminal with the green ground wire from the new cord, I kept popping the breaker.

When I disconnected the internal green wire, the dryer would work, but for only about 10 seconds. If I touched the disconnected wire back to the ground, I got sparks, which indicates to me, the green internal wire has a live current and is hot.

Is it possible the electrican who wired the plug-in accidently wired a hot wire to the neutral causing this problem. I did pull out the outlet to check the ground, and the bare ground copper is going to the round hole terminal in the outlet but I did not check the others.

Confused here, and thanks.

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jbfan

· #2 · May 1, 2009

You can not install a 4 wire dryer cord to fit into a 3 wire receptacle.
Replace the 4 wire cord with w 3 wire cord, connect the bonding strip in the dryer back to the center connetion and then wire the cord with the black and red on the outsides and the white to the middle.

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johnnyboy

· #3 · May 1, 2009

Retired sailor said:
When the old 3-wire was connected, there was a green wire coming out of the dryer (internal) and connected to the ground terminal. When this green wire was connected to the ground terminal with the green ground wire from the new cord, I kept popping the breaker.

your ground and neutral are only connected together at the breaker box. your older style cord connected to a new socket, was essentially creating a 2nd bonding of your ground/neutral via the green wire in your dryer at that location.

electricity always follows a path of least resistance and your two poles are never quite balanced, so there's always current passing through the neutral.

if the neutral wire is, say, 100ft path, and the ground is 50ft, it's gonna take the ground shortcut instead of the intended neutral which is why you saw the spark.

it seemed to make sense in my head heh

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Retired sailor

Discussion Starter · #4 · May 1, 2009

Reply to JBFAN/Johnny Boy with hot ground wire on dryer

To JBFAN and JohnnyBoy, thanks for the info; however, I'm not trying to run a 4-prong pigtail into a 3-prong receptacle. The dryer has four terminals in the back as indicated: Far Left: Ground Terminal, Next: Black Terminal, Third: Neutral Terminal, and Fourth: Red Terminal.

I have the dryer wired with a four-prong receptacle and when I plug it into the 4-prong outlet, circuit breaker pops.

The sparking I get is when I touch the existing green ground that is coming out of the internal part of the dryer. It appears, because of the sparking, it is a "hot" green wire and not being used as a ground.

When the dryer was origionally wired with a 3-prong pigtail, the far left terminal had the internal green wire connected to the ground terminal; 2nd terminal (gold) had black wire; 3rd terminal (silver) had white wire; and 4th terminal (gold).

According to instructions, I have the dryer wired correctly, but what I don't understand is what to do with the internal green wire that sparks if in contact with metal; or pops the circuit if attached to the ground terminal.

Thanks for your assistance.

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bob22

· #5 · May 3, 2009

Was the wiring changed to the new 4-prong outlet from the old 3-prong receptacle?

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joed

· #6 · May 3, 2009

Dryer could be defective.
Receptacle could be wired wrong.

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HouseHelper

· #7 · May 3, 2009

I'd check the wiring at the receptacle.

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Timster

· #8 · May 4, 2009

First, I would test the outlet, as mentioned previously.

If the dryer is an old dryer: now that the outlet is confirmed as good, and you have a hot ground, you will need to take the dryer apart and trace the ground wire inside the dryer to where it is hot.

Test for continuity between the ground and the neutral/hots until you find out what is going on.

Having done a few repairs on appliances, I have found many burned out wires, etc. that you wouldn't believe. You will find it, but it will likely be inside the dryer.

Don't work on the dryer with the cord plugged into the outlet.

If the dryer is new, I don't know what to say.

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nap

· #9 · May 4, 2009

The sparking I get is when I touch the existing green ground that is coming out of the internal part of the dryer. It appears, because of the sparking, it is a "hot" green wire and not being used as a ground.

When the dryer was origionally wired with a 3-prong pigtail, the far left terminal had the internal green wire connected to the ground terminal; 2nd terminal (gold) had black wire; 3rd terminal (silver) had white wire; and 4th terminal (gold).

According to instructions, I have the dryer wired correctly, but what I don't understand is what to do with the internal green wire that sparks if in contact with metal; or pops the circuit if attached to the ground terminal.

what internal green wire are you talking about? Maybe a bonding wire that was disconnected when you changed from a 3 wire to a 4 wire pigtail on the dryer? Where is it connected in the dryer?

It almost sounds like a bonding wire that connects the neutral terminal on the dryer to the ground connection of the dryer. If so, it needs to be secured so it is insulated from anything else.

Along with the others suggestions, it sounds as if your receptacle may be wired incorrectly.

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Stubbie

· #10 · May 4, 2009

My feeling is you have a hot connected to the neutral terminal of the receptacle.
MY question is how did you install a 4 wire receptacle to a 3 wire branch circuit from the panel?

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Ultrarunner2017

· #11 · May 4, 2009

It really sounds like the new 4-wire receptacle has been improperly wired.
If the dryer worked fine on the 3-wire system, it will work on a properly wired 4-wire system.
The only thing you are changing is the bonding point of earth and neutral.
On the old configuration, you have earth (EGC) bonded to neutral at the dryer, on the terminal block. In the cord, you have two hot and one ground/neutral which connects to the neutral wire on the receptacle.

On the 4 wire system, you have a separate neutral and ground (earth) running from the SE panel to the 4-wire receptacle. Then, you have a 4 wire plug and cord running to the dryer's terminal block.
You do not bond neutral to ECG (ground) on the dryer, or on the receptacle. This is done only in the SE panel.

In your 4-wire system, bonding the neutral to the ECG at any point (in the dryer or at the receptacle) will not cause the breaker to trip, unless it is a GFCI breaker.
There may be some potential difference between the ECG (earth/ground) wire and the neutral (white) wire, but connecting them together will not cause the breaker to trip if all else is wired correctly.

Did you purchase this 4-wire cord with the plug attached? If not, the problem could be in the plug wiring or the receptacle wiring.

First thing I would do is SHUT OFF POWER AT THE BREAKER (which should be double-pole type). BE ABSOLUTELY CERTAIN THAT POWER HAS BEEN CUT BEFORE MAKING ANY OHMMETER/CONTINUITY TESTS!!
You should first check the receptacle slots, each one to each other one with a voltmeter that is set to read 250V or higher, or a voltage tester that will read 110/220V to be sure that power has been cut.

Next: With the dryer unplugged, use an ohmmeter or continuity tester to check for continuity between the round hole (ECG, earth, ground) and the neutral slot on the receptacle.
If wired correctly, there should be almost no resistance between these two terminals, since they are bonded in the SE panel.

Next: Check the resistance between each of the hot slots of the receptacle to each other and to neutral and ground slots. All of these should read open. Very high resistance (more than a Megohm).
Explanation: With the breaker OFF, both hot legs are disconnected, so there is no circuit from either of them to anywhere else.

Of course the above assumes that there is nothing else on this circuit. The dryer MUST be on a dedicated branch.

It might be helpful if you could post a photo of the whole situation.
Take a photo of:
>The receptacle with wiring connected as it is now
>The dryer terminal block showing all wires connected per instructions

Be very careful! You are working with potentially lethal voltages and currents!

FW

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