changing dryer cord - Contractor Talk - Professional Construction and Remodeling Forum

boman47k · 09-20-2009, 03:56 PM

Bought a new dryer and of course it has a 4 wire pigtail. Is it necessary to change the old 3 wire rec in my house, or can I just change the 4 wire oigtail to a 3 wire off the old dryer. Now if this was the opposite situation, I would have no problem. Bend the ground strap back, neutrtal to the middle, ground to the cab , good to go. Where I am a little bumfuzzled is do I put the green ground on with the white neutral at the power block?

Tiger · 09-20-2009, 04:20 PM

IMO the receptacle needs to be 4-conductor AND the circuit wiring needs to be 4-conductor.

Jim M · 09-20-2009, 05:02 PM

Do you have a wiring system that will support the 4 wire receptacle?

boman47k · 09-20-2009, 08:33 PM

Quote:

Originally Posted by Jim M

Do you have a wiring system that will support the 4 wire receptacle?

If you mean do I have a 4 wire conductor at the rec, no. I am hoping I can avoid having to run a 4 wire and that the green case ground can be used in place of the grounding strap. This a Samsung unit. I have replaced many 3 wires for 4 wires on dryers a few years ago. In those cases, I just bend the ground strap back, run white to the middle terminal, black on one hot side, red on the other. The reverse had me a little confused. As of now I have the green ground wire in the middle along with the white nuetral/ground.

So basically it is a new dryer on existing 3 wire conductor. When I bought it, I thought I would have to run a 4 wire but was told I could just swap pigtails. When I vcame to the grounding, I had to stop and think. Thought maybe someone on here could rest my mind a little.

Celtic · 09-20-2009, 08:53 PM

Quote:

Originally Posted by Tiger

IMO the receptacle needs to be 4-conductor AND the circuit wiring needs to be 4-conductor.

The NEC begs to differ:

Quote:

Originally Posted by 2008 NEC

250.140 Frames of Ranges and Clothes Dryers.
Frames of electric ranges, wall-mounted ovens, counter-mounted cooking units, clothes dryers, and outlet or junction boxes that are part of the circuit for these appliances shall be connected to the equipment grounding conductor in the manner specified by 250.134 or 250.138.

Exception: For existing branch-circuit installations only where an equipment grounding conductor is not present in the outlet or junction box, the frames of electric ranges, wall-mounted ovens, counter-mounted cooking units, clothes dryers, and outlet or junction boxes that are part of
the circuit for these appliances shall be permitted to be connected to the grounded circuit conductor if all the following conditions are met.
(1) The supply circuit is 120/240-volt, single-phase, 3-wire; or 208Y/120-volt derived from a 3-phase, 4-wire, wye-connected system.
(2) The grounded conductor is not smaller than 10 AWG copper or 8 AWG aluminum.
(3) The grounded conductor is insulated, or the grounded conductor is uninsulated and part of a Type SE service entrance cable and the branch circuit originates at the service equipment.
(4) Grounding contacts of receptacles furnished as part of the equipment are bonded to the equipment

The short version:
If the existing is a 3-wire ~ use a 3 wire.
All else must be a 4-wire.

The OP has an existing 3-wire circuit.

Celtic · 09-20-2009, 08:54 PM

Quote:

Originally Posted by boman47k

So basically it is a new dryer on existing 3 wire conductor. When I bought it, I thought I would have to run a 4 wire but was told I could just swap pigtails. When I vcame to the grounding, I had to stop and think. Thought maybe someone on here could rest my mind a little.

Put the 3-wire cord on, bond the neutral and ground in the appliance, rest.

bwalley · 09-20-2009, 08:56 PM

Quote:

Originally Posted by boman47k

Bought a new dryer and of course it has a 4 wire pigtail. Is it necessary to change the old 3 wire rec in my house, or can I just change the 4 wire oigtail to a 3 wire off the old dryer. Now if this was the opposite situation, I would have no problem. Bend the ground strap back, neutrtal to the middle, ground to the cab , good to go. Where I am a little bumfuzzled is do I put the green ground on with the white neutral at the power block?

The cord can be changed to a 3 wire, yes the green (ground) and white (neutral) go to the same location, there will be a wiring schematic that shows you how wire the dryer, it is usually a bonding strap.

If you were installing a new circuit, code would require you to go to a 4 wire receptacle.

Celtic · 09-20-2009, 09:06 PM

What really needs to be determined is:
Is the existing REALLY a 3-wire circuit or not?

Many times, the AC jacket is over looked as the EGC here.

boman47k · 09-20-2009, 09:22 PM

Quote:

Originally Posted by Celtic

What really needs to be determined is:
Is the existing REALLY a 3-wire circuit or not?

Many times, the AC jacket is over looked as the EGC here.

Yes, this is a 3 wire circuit. I ran it myself a few years ago. I did not wait for an answer, just wired it the way you said to do it. I worked on appliances several years ago, but still had to stop anf think on this one not knowing if the internal wireing what I was used to.

I called myself checking to see if the green ground wire/case ground was connected to the frame somewhere as I could not see where it was connected. I did not get a beep or a reading. That made me scratch my head a little. Seemes to me it should have given a signal or shown som ekinf of continuity between the ground and the caseing.
The old one showed a connection between the ground starp and the casing, bulkhead, etc., but the strap was fastened to the powerblock on the back and it was a metal bracket going around the powerblock and attached to the case so it made sense.

Anyway, problem solved... I hope. Hey it works! Just hope if it ever has a short, it does hurt hurt!

All jokes aside, I did not trust my knowledge enough on this matter to be completely sure of it being safely grounded.

Thanks for the responses.

Celtic · 09-20-2009, 09:28 PM

boman...if you get a chance and the motivation....make it a 4-wire.....technically, the 3-wire went out in like 1996 - but the NEC realizes many homes were built prior to that date.

boman47k · 09-20-2009, 09:46 PM

Quote:

Originally Posted by Celtic

boman...if you get a chance and the motivation....make it a 4-wire.....technically, the 3-wire went out in like 1996 - but the NEC realizes many homes were built prior to that date.

I knew all new stuff was supposed to be 4 wire and thought I would have to run another circuit. But then I thought maybe existing circuit was excempt. Seems I was right.

Motivation is what I need to go ahead and change this thing out and get the grouind sperated from the nuetral. Having said that, how did we get by for so manyu years with the old way? Actually, I guess there some that didn't.

I still have some 4 wire rec's in my shop. In fact, I took a strain relief off one to put on this dryer cord. So, I have the rec's and cords. I may change them out...in the near future.

Celtic · 09-20-2009, 10:41 PM

Quote:

Originally Posted by boman47k

... how did we get by for so many years with the old way?

ya know, up until last week, the world was flat and there were 9 planets

Things change.
What was once held as true is challenged.

To be even more eloquent, shat happens

rselectric1 · 09-20-2009, 10:54 PM

In the Chicago suburbs where everything must be run in emt, I sometimes wonder myself if the metal emt is a substantial ECG. We have to make our own 4th wire to the Eg via a green screw.
It's all so confusing, I just want to be a fireman or superhero when I grow up!

480sparky · 09-20-2009, 11:01 PM

Quote:

Originally Posted by rselectric1

In the Chicago suburbs where everything must be run in emt, I sometimes wonder myself if the metal emt is a substantial ECG. We have to make our own 4th wire to the Eg via a green screw.
It's all so confusing, I just want to be a fireman or superhero when I grow up!

EMT is a far better ground than any conductor you can fit inside of it.

Celtic · 09-21-2009, 04:02 PM

Quote:

Originally Posted by 480sparky

EMT is a far better ground than any conductor you can fit inside of it.

Quote:

Originally Posted by rselectric1

I just want to be a fireman or superhero when I grow up!

Ohmy · 10-08-2009, 01:14 PM

Is it is a newer/nicer dryer? Older dryers have 240v motors and elements. Newer dryers have 120V components on them?

boman47k · 10-08-2009, 01:49 PM

Quote:

Originally Posted by Ohmy

Is it is a newer/nicer dryer? Older dryers have 240v motors and elements. Newer dryers have 120V components on them?

New. I would think the element would still need 220/240 and the motor would still be 110/120.

Plumber_Bill · 10-08-2009, 01:56 PM

IF YOU ARE ... A plumber, electrician, remodeler, handyman or what ever.

Never - Never - Never ... Reach down behind a dryer and pull the plug to disconect it. Always turn the breaker off 1st!

See the proof -- but I did not get a shock. Still don't know why?

boman47k · 10-08-2009, 06:39 PM

Why what? Why you got a shock? Thats easy enough to see with the condition of the cord. I can guess why the lead ins are the way they are, but what happened to the plug end?

Heheh, I guess you mean why a 4 cord should be used. I do know the purpose of the 4th wire. You are right, that kind of brings it into better focus.

480sparky · 10-08-2009, 07:29 PM

Quote:

Originally Posted by boman47k

........... but what happened to the plug end? ............

Because it plugged in with the cord up, and it was bent back over just before the dryer was slammed up against it, literally folding it. You can still see the curvature of the cord caused by the torture inflicted on it.