Electricians chime in please - 240V wiring mistake?

wavinwayne

wavinwayne

Joined
Jan 6, 2005
Messages
9,613
Location
North Alabama
I won't bore with details; here are the pertinent facts. Today I discovered a Leviton 4 prong 30 Amp 240V Surface Mounted Outlet wired (not by me) in the following way:
Romex 10/2 (NOT 10/3) wire coming into a standard blue plastic box (should it be metal?).
Black and White wires connected to Brass terminals. White wire being used as a hot wire.
Ground wire connected to ground terminal.
Bare jumper wire ran between ground and neutral terminals.

There is a dryer plugged into this outlet and it has been operating like this for at least a couple of years. What are the issues and potential risks with the outlet being wired this way? I know who wired it and was wondering how much this should add to the disdain I already have for this knucklehead.
 
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am not an electrician ,but have seen my share of wiring in houses . never seen blue box used for surface mount . 2 hots and a ground used to be standard for years and there are still many houses using it. what is suspect is the bootleg ground.
 
How much money do you want to spend to fix it?

Using a white as a hot is acceptable as long as it's marked on each end.

Is the ground an insulated ( green ) wire?
You could use it as a white as long as it is marked on each end.

Ultimately, the white and green end up landing the same place in the panel.

If you wanted, you could run an exposed ground wire #6 or bigger to the cold water line, if it's copper.

I would leave it in the plastic box until I separated the grounding conductor out.

Technically, the white is referred to as the grounded conductor... not as a common wire.

The Green or bare wire is the grounding conductor.

In a perfect world you would pull new wire and start over.

Reality is that it's been working fine as is.
 
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KJSmith said:
How much money do you want to spend to fix it?

Using a white as a hot is acceptable as long as it's marked on each end.

Is the ground an insulated ( green ) wire?
You could use it as a white as long as it is marked on each end.

Ultimately, the white and green end up landing the same place in the panel.

If you wanted, you could run an exposed ground wire #6 or bigger to the cold water line.

I would leave it in the plastic box until I separated the grounding conductor out.

Technically, the white is referred to as the grounded conductor... not as a common wire.

The Green or bare wire is the grounding conductor.

In a perfect world you would pull new wire and start over.

Reality is that it's been working fine as is.
Click to expand...


No, that is not necessary correct. It matters where the wires go IF these wires for the dryer are coming from a “sub panel” OR a house that has a “service disconnect” ( so the fireman can turn the power off from outside before they go in the building if there is a fire ) The service disconnects is before the main panel. This makes the main panel a “ sub panel “ and needs to be wired to segregated ground and neutral bars. This is also called an “un bonded neutral.” Older dryers have a 3 prong plug and technically can be wired with 10/2 wire, and don’t t have a neutral. But I myself would want a separate “ chassis ground “ for a more safe install. Do a new rewire and do it to code. If you don’t feel you are up to it call in an electrician. Or watch a bunch of YouTube videos from actual electrician’ channel so you don’t miss something that a layman forgot to do correctly. Also if you have a newer home with arc fault/gfci breakers “ jumping” ground and neutral will create a lot of problems.
 
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Mainia said:
No, that is not necessary correct.
Click to expand...
I assume you are concerned about where the grounded and grounding conductors are bonded.
They still end up the same.
Current will take the easiest path to ground.

I certainly did not cover every exact issue there may be.

As it is now, it's one conductor acting as grounded and grounding.

I also do not necessarily go by the letter of the code.
I am more a spirit of the code guy.

The thing that is important is getting the chassis ground.
On that we agree.
He can do that by running a grounding conductor to a copper cold water line or if he is on an exterior wall, he can drive a ground rod and connect to that.
Making it safe as possible is the goal.
Several ways to accomplish that.
Not all technically correct.

As I said above, best practice is to pull new wire and start over.
 
You don't have separate neutral and ground. If he was going to run 10/2 w/ ground then it would have been better to have wired in a 3 prong 30a dryer receptacle and then change out the dryer cord to a 3 wire. (Making sure in the dryer wiring that the neutral and ground are connected together.) This is copied from a google search...."Yes, a 4-wire dryer outlet is considered significantly safer than a 3-wire outlet because it has a dedicated grounding wire, which provides a separate path for electrical current to travel in case of a fault, greatly reducing the risk of electric shock, especially in a potentially wet environment like a laundry room; whereas a 3-wire outlet combines the neutral and ground wires, increasing the potential for shock hazards." Your other question about the box. Is the wire going into the surface mounted plastic box in a piece of pipe, either PVC or EMT? Usually a metal 2 gang deep box w/EMT (3/4") pipe would be the mounting choice.
 
Most electric dryers don't have or need a neutral circuit. There is no "neutral" connection inside the dryer. All of its electrical parts work on 240 volts between the two hot wires. The third wire in the cord is for grounding only and three wire wiring in the house is acceptable.

Someone may have rigged that plug for uses other than a dryer. For example a 50 amp RV plug is 4 pins two hots neutral and ground.
 
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wavinwayne said:
I won't bore with details; here are the pertinent facts. Today I discovered a Leviton 4 prong 30 Amp 240V Surface Mounted Outlet wired (not by me) in the following way:
Romex 10/2 (NOT 10/3) wire coming into a standard blue plastic box (should it be metal?).
Black and White wires connected to Brass terminals. White wire being used as a hot wire.
Ground wire connected to ground terminal.
Bare jumper wire ran between ground and neutral terminals.

There is a dryer plugged into this outlet and it has been operating like this for at least a couple of years. What are the issues and potential risks with the outlet being wired this way? I know who wired it and was wondering how much this should add to the disdain I already have for this knucklehead.
Click to expand...
Just for clarity, what are the markings on the "Leviton 4 prong 30 Amp 240V Surface Mounted Outlet" ?

Like the 14-30R?

1734262714455.webp


1734262982189.webp



Not Like this on the right?

1734262750713.webp
 
If the blue electrical box is sub wall mounted that’s fine if it’s exposed it’s susceptible to damage. A dryer can run on 10/2 w/ ground and is sized accordingly with a 30A circuit. There’s a jumper on the terminal wiring block at the back of the dryer the neutral and ground would be bonded together for the old wiring method of a 10/2 with ground. It’s no longer code and a 10/3 with ground is now required separating the neutral and ground and the brass jumper would be removed. On a 10/2 nm cable (romex) many times the white will be used for 220/240v appliances.. the white should be marked at both ends with red or black electrical tape or permanent marker indicating it’s a hot leg in the circuit.

1734266118238.webp

Old style left current on right wiring
 
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In WWII, to save copper, the US decided to allow kitchen stoves to use the ground wire as neutral. They had things like built in clocks that ran on 120V and some stoves even had a 120V "convenience outlet." This was determined to be safe until 1996!

Now dryers aren't stoves, but they ship the same-- with an easily detachable pigtail and instructions to wire for 2-plus-ground or 3-plus-ground. The dryer makers know there's old outlets out there in service grandfathered in under old codes. If it were my house, I'd put it all back together the way it was and pretend I didn't see anything. Effectively that bootleg jumper you found in the receptacle would be inside the dryer if you hooked up a different pigtail (and outlet) and followed the dryer maker's instructions.

As for the white Romex, wrap the end in a little bit of red electrical tape, and do the same in the breaker box. Now everyone who sees it will know it's the 2nd hot.
 
The guy above me is correct. It’s a 3 wire outlet that has been incorrectly swapped to a 4 wire outlet.

It’s really no different than using an old 3 wire cable and then making the connections in the back of the dryer.

I’d leave it alone.

An electrician could do it right with a new wire pull. Not sure I’d spend the $1000 (or more) this would cost.
 
Thanks to everyone who responded. The guy who did the wiring is a con man who would cheat his mother out of a penny. I also don't own the house, so as long as the ghetto wiring isn't an immediate fire or shock hazard, I'm leaving it alone. The only reason I noticed it is because I was unplugging the dryer prior to cleaning the vents, and notice the surface mount connector was barely attached to the wall. It was the worst mounting job I've ever seen. A blind toddler could have done it better. I got it re-attached to the wall securely.
 
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wavinwayne said:
Thanks to everyone who responded. The guy who did the wiring is a con man who would cheat his mother out of a penny. I also don't own the house, so as long as the ghetto wiring isn't an immediate fire or shock hazard, I'm leaving it alone. The only reason I noticed it is because I was unplugging the dryer prior to cleaning the vents, and notice the surface mount connector was barely attached to the wall. It was the worst mounting job I've ever seen. A blind toddler could have done it better.
Click to expand...
Yeah I was worried maybe it was a higher rated outlet with only 10G wire. Dangerous if someone plugs something else in…not knowing the breaker rating

That said well if they need an N not going to be good obviously

And yep the dryer works
 
One more question for everyone: If I were to ever replace the dryer, and I leave the 240V outlet wired as is, on a new dryer would I just copy how the dryer wire is currently connected to the existing dryer?
 
wavinwayne said:
One more question for everyone: If I were to ever replace the dryer, and I leave the 240V outlet wired as is, on a new dryer would I just copy how the dryer wire is currently connected to the existing dryer?
Click to expand...
Best would be bring it up to code as mentioned but your jurisdiction may or may not require you too. As in you may be grandfathered in. But essentially to answer your question if the old cord is in good usable condition, you would take the cord from the old unit wire each one of the wires to the black and red on the terminal block of the dryer and keep the bonding jumper in place bonding the neutral and ground. There shouldn’t be any makeshift jumpers in the junction box, the two wire nm “Romex” cable should be marked with black or red tape or permanent marker on the white conductor, indicating it is a hot wire. It does not matter which wire goes on X or Y on the back of the receptacle as long as the ground is on the neutral lug. At the electrical panel side again white should Be marked as a hot conductor and the ground will be on the ground/neutral bus. the black and re-identified white conductor will go on a 2-pole double throw 30A breaker. This all being said keeping existing wiring just making sure it is safe.
 
wavinwayne said:
To be clear, on the current outlet, there is a jumper wire between the ground and neutral terminals. Are you saying this jumper wire should not be there, or am I misunderstanding? Thanks
Click to expand...
Do you have a picture to clarify? The receptacle is a 3 or 4 prong?
 
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