3 Wire, 4 Wire Code

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Power Tech

Senior Member
I re-wired 200 appliances :mad: ....100 ranges and 100 dryers.



In my scenario, it was our responsibility...we bought them, they wired them wrong..if we installed them "as is" and "something went wrong" we would have been liable.


When I asked that same question you did here on the forum...the result was mixed.

IMHO, if the EC is installing a piece of equipment, it IS his responsibility ~ 110.3(A)(1) et al

As usual.:roll:
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
I have to go back to as house I did a panel change.

I got a correction notice for the dryer. I installed a 3 wire to match the customers dryer.

what was there before you touched it?

When you say you installed a 3 wire 10-3 romex or a 3 wire recep. Because if you installed a 10-2 then I belive that was never permitted.
As the bare ground may not carry nuetral current!
 

480sparky

Senior Member
Location
Iowegia
.........In my scenario, it was our responsibility...we bought them, they wired them wrong..if we installed them "as is" and "something went wrong" we would have been liable......

YOU buy and supply, as well as install, the dryers?

.........IMHO, if the EC is installing a piece of equipment, it IS his responsibility ~ 110.3(A)(1) et al

As I said, it's the appliance supplier that typically installs them in my neck of the woods.
 

kbsparky

Senior Member
Location
Delmarva, USA
Nope, the neutral and the ground were crimped together with a ring terminal to the frame of the dryer.

That is exactly what is shown here. That green/yellow stripe wire is crimped to the neutral, with a ring terminal connected to the frame.

How many dryers have been connected to a 4-wire cord like that one was, and thought it was complaint?
 

480sparky

Senior Member
Location
Iowegia
YOU don't ?

LOL

Seriously though...someone has to...why should the GC get paid for something we have the burden of humping around, installing, etc.

If I was to bid a whole development of tract/spec homes, yea, I'd provide an option to supply all the appliances. It would be a good profit margin item.

But 99.999% of my customers want to do their own shopping for appliances.
 

Power Tech

Senior Member
what was there before you touched it?

When you say you installed a 3 wire 10-3 romex or a 3 wire recep. Because if you installed a 10-2 then I belive that was never permitted.
As the bare ground may not carry nuetral current!

Nothing, I installed a 3/4 EMT. I will change the dryer whip to a 4 wire and the receptacle to a 4 wire.

I do believe a 10/2 was legal ??? Somewhere in the past.
 

hurk27

Senior Member
Did the dryer terminal block look like this?




Here is how I left it after repairs: Notice I had to remove that green/yellow wire, and wrap some tape on the end.


I think you goofed, that yellow striped green wire runs through the dryer to all the componits and some like the motor are mounted on rubber mounts.

in your post 18 image, was the correct way it is to be wired for a 4 wire system, as the ground has already been removed from the neutral, when these dryers come wired for a 3 wire system that ground wire will be under the same screw as the neutral.
this photo is the correct way for a 4-wire:
attachment.php
 

kbsparky

Senior Member
Location
Delmarva, USA
Wayne, I would suggest that the next time you look at a dryer terminal connection similar to the one shown here, take a REAL CLOSE LOOK! That green/yellow wire connects directly to the NEUTRAL connector block, and is there for a 3-wire connection scheme. IT MUST BE REMOVED AND ISOLATED, OR REATTACHED TO THE NEUTRAL TO BE COMPLIANT FOR A 4-WIRE CONNECTION!


You can't tell from those photos, since it is literally hidden from view, but closer inspection reveals this is case. Testing with a continuity tester also confirms this. I checked with many instruction manuals, which also back this assertion up.
 

hurk27

Senior Member
Wayne, I would suggest that the next time you look at a dryer terminal connection similar to the one shown here, take a REAL CLOSE LOOK! That green/yellow wire connects directly to the NEUTRAL connector block, and is there for a 3-wire connection scheme. IT MUST BE REMOVED AND ISOLATED, OR REATTACHED TO THE NEUTRAL TO BE COMPLIANT FOR A 4-WIRE CONNECTION!


You can't tell from those photos, since it is literally hidden from view, but closer inspection reveals this is case. Testing with a continuity tester also confirms this. I checked with many instruction manuals, which also back this assertion up.

Wow, that would be confusing, as I have seen many of those that the green wire connected to the wiring harness green, and this end was a ring terminal under the neutral, I would have never expected a green wire being permanently connected to the neutral. That is a UL issue

Most dryers have just a brass strap bonding the neutral to the frame, and all you do is remove it and put the cord ground to where it was bonded to the frame.

Guess it pays to check to be sure.

If I ever find one like that, I will take photos of it and where it is connected to the neutral , and send it to UL, because that is just wrong.
 
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I have not wired a dryer in years, but I am with Wayne on this one. The green/yellow stripe would seem to be the equipment ground of the equipment. It does make sense that something would have to be bonded to the frame though.
I usually saw copper strap bonded to the neutral and frame that would need to be cut if I had a 4-wire branch circuit.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
I do believe a 10/2 was legal ??? Somewhere in the past.
As an SE cable, yes; as NM cable, no. An SE cable bare can be used as a neutral; an NM cable bare cannot be.

Remember, this was a case of the neutral being able to do double duty as the EGC, not the other way around.
 

hillbilly

Senior Member
Wayne, I would suggest that the next time you look at a dryer terminal connection similar to the one shown here, take a REAL CLOSE LOOK! That green/yellow wire connects directly to the NEUTRAL connector block, and is there for a 3-wire connection scheme. IT MUST BE REMOVED AND ISOLATED, OR REATTACHED TO THE NEUTRAL TO BE COMPLIANT FOR A 4-WIRE CONNECTION!


You can't tell from those photos, since it is literally hidden from view, but closer inspection reveals this is case. Testing with a continuity tester also confirms this. I checked with many instruction manuals, which also back this assertion up.

That's correct....only I wouldn't re-attach it to the neutral, simply cut it off.

Just last Friday, I installed a new circuit for a (older) existing dryer.
The old circuit was 3 wire.....2 hots and a ground.
I replaced it with a 4 wire circuit.

I also replaced the (3 wire) cord on the dryer with a 4 wire cord.

On the dryer, there was a (green) grounding wire that was bonded to the dryer chassis.
The other end of this green wire went to the top of the center (neutral) terminal and was bonded to the white (neutral) wire.

I clipped off the existing green wire, and bonded the grounding wire of the cord to the dryer chassis.

I'm positive that it's the proper connection of the neutral/grounding conductors for this dryer.

I believe that this bonding set-up will be found on older model dryers only.

The newer dryers will have a copper bonding strap that runs from the center (grounded) terminal to the dryer chassis.
On these dryers, you will simply remove the copper strap and bond the (green) grounding conductor (in the cord) to the dryer chassis.

steve
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
That's correct....only I wouldn't re-attach it to the neutral, simply cut it off.

Just last Friday, I installed a new circuit for a (older) existing dryer.
The old circuit was 3 wire.....2 hots and a ground.
I replaced it with a 4 wire circuit.

I also replaced the (3 wire) cord on the dryer with a 4 wire cord.

On the dryer, there was a (green) grounding wire that was bonded to the dryer chassis.
The other end of this green wire went to the top of the center (neutral) terminal and was bonded to the white (neutral) wire.

I clipped off the existing green wire, and bonded the grounding wire of the cord to the dryer chassis.

I'm positive that it's the proper connection of the neutral/grounding conductors for this dryer.

I believe that this bonding set-up will be found on older model dryers only.

The newer dryers will have a copper bonding strap that runs from the center (grounded) terminal to the dryer chassis.
On these dryers, you will simply remove the copper strap and bond the (green) grounding conductor (in the cord) to the dryer chassis.

steve

I would like to see some proof that cutting the green/yellow and leaving it disconnected is recommended.

What if it is for bonding something not connected to the frame?
 
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