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So what do I do with this 3 wire cable into a 4-wire dryer outlet?

enter image description here

I had put a 4-wire cord on the dryer and took off the ground-neutral link in the dryer, but it doesn't operate. (I'm guessing the floating neutral is the issue.)

Should I put the ground-neutral link back on the dryer and use the 4-wire cord into this 4-wire outlet?

Should I link the ground and neutral inside this outlet?

Aside

When you use a GFCI to without a ground to replace a 2-prong outlet, you are supposed to label it with "NO EQUIPMENT GROUND"

If I leave the plug as-is, would it be better to mark it as "NO EQUIPMENT NEUTRAL" or to move the bare wire to Neutral and label it as "NO EQUIPMENT GROUND"?

2nd Aside -- when I touched the hot water washer tap, the corroded black pipe stub broke and the tap fell off in my hand and flooded. So plumbing is first priority tonight. // Fixed.

The breaker is a 40A in a 200A GE "TM2020C MOD.1" load center:

enter image description here

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    Best would be to replace the three wire cable with a four cable from the panel to the outlet/receptacle. Second best is to add a separate ground wire to the receptacle from the panel.
    – crip659
    Jan 28, 2023 at 23:09
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    Dryer needs 240 p-p, but it also needs 120 V for the electronic, that is what the neutral was for.
    – Traveler
    Jan 28, 2023 at 23:14
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    When you say you have a floating neutral I think you must mean that the neutral is not connected to the neutral of the receptacle. These dryers will not operate without a neutral because they use 120 V power for some functions. You can get it to work if you use a GFCI breaker in the panel and separate the neutral and ground at the back of the dryer. Alternatively keep the existing standard breaker and bond the neutral and ground at the back of the dryer as in a 3-wire setup. Jan 28, 2023 at 23:15
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    Since you have a bare neutral wire, separate ground might be used. Would want at least 10 gauge(8 gauge better) ground wire, but insulated with green covering would be better to keep away from the bare neutral. Three wire dryer connections are now banned for being unsafe. Can only use them if the circuit is not changed since late 90s. Most people recommend to change to the safer four wire receptacles/plugs, including replacing the cable from the panel.
    – crip659
    Jan 29, 2023 at 0:32
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    OP you refer to a 40 A breaker. AFIK electric dryers usually are fed by a 30 A breaker and #10 copper or aluminum equivalent. A 40 A breaker would need #8 Cu or Al equivalent. If you want the dyrer to operate right now, I think you would transfer the bare aluminum to the silver neutral screw from the green ground screw. This would be a 3-wire connection and wiring on the back of the dryer as for 3-wire. Later you could put a suitable ground wire on the ground screw of the receptacle and then change the dryer back to 4-wire. Jan 29, 2023 at 1:12

1 Answer 1

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Why do you think it's ground?

Despite your constant protests that you have ground and not neutral, the fact is that your 3-wire dryer wiring is hot-hot-neutral. Your misunderstanding here is due to a chain of bad decisions by the prior nitwit.

  • Prior nitwit had their dryer fail and replaced it.
  • The new dryer had a 4-prong plug.
  • Rather than read the instructions, prior nitwit replaced the 3-prong plug with a 4-prong plug, however they had never seen an SEU cable in their whole life, so they did not know what to do with the bare wire.
  • They insanely placed the bare wire on GROUND, leaving neutral unconnected which is a suicide play on a NEMA 14 type outlet. All 120V loads will be exposed to 240V - good way to set an RV on fire, by the way. Never, ever, ever, ever do this. Madness!
  • The dryer either didn't work, or fried the 120V loads and a repairman fixed it. At some point, someone insanely installed the neutral-ground bonding jumper on the dryer, with the 4-prong plug - a good way to burn your house down! Never do this either!
  • Then, you arrived on the scene and found this mis-wired fiasco.

Why doesn't it work?

You haven't connected anything to the neutral wire, is why your dryer isn't working. The neutral causes the dryer to work. The ground causes the dryer to be safe. You only have one, and so far, you've chosen "safety" over "function" - which honestly, is a good call.

Should I put the ground-neutral link back on the dryer and use the 4-wire cord into this 4-wire outlet?

Should I link the ground and neutral inside this outlet?

HELL NO. Absolutely do not do that.

From the knotty appearance of the neutral wire in your wall, it appears this is SEU cable with a bare neutral. Further, it appears to be aluminum which is fine however you need to use sockets which are certified for aluminum wire. (they say "AL-CU" or similar symbols).

So let's work the problems one at a time.

Lack of ground

There are two ways to go here. One is to replace the circuit breaker with a 2-pole GFCI breaker, don't actually run a ground wire, and then label the 4-wire socket "GFCI Protected / No Equipment Ground". That's it, you're done. This solution does not require running a ground wire.

The other is to retrofit an actual ground wire. You can't retrofit a neutral, but you can retrofit a ground. It does not need to follow the route of the hots and neutral.

The ground must be 10 AWG or larger, can be bare, and can go to anywhere with a 10 AWG or larger ground back to the panel - water heater, A/C, any box with non-flexible metal conduit back to the panel, or even the bare copper Grounding Electrode Line going out to the ground rods. Or the panel itself of course.

The bare SEU neutral needs to be insulated from the ground. They mustn't touch.

Aluminum wire

Make sure you are choosing a dryer socket which is "AL-CU" rated for both copper and aluminum wire. That's it.

Now if it feels like there ought to be something else here, there is. Long after attention turned away from aluminum, wire connection burn-ups kept happening with copper wire. They worked the science and found that screw torques have a huge impact. In NEC 2014 they legislated use of torque drivers on any terminal which specifies a torque.

We can only guess that applied to aluminum in equal measure. But of course when a copper wire fails due to lack of torque, nobody goes "See? Proof that copper is unsafe".

So yes, you do need to torque these terminals to spec, but you needed to do that anyway.

The notable lack of junction box

Normally, a cable coming through the wall into one of those surface-mount boxes would be fine. However, that one is too short and the cable sheath is already stripped before it comes through the wall. That's not allowed.The sheath must enter the cable clamp on the receptacle.

Since the wall seems to be open behind, I would carefully open that up and make a hole right-sized for a junction box embedded in the wall. Then you will have enough sheath length to enter the box properly. You can then use a dryer outlet which mounts in the box.

If you use a metal box, you'll have no trouble finding a cable clamp appropriate for #8 SEU, and the metal box will also carry ground to the outlet and you can terminate the retrofit ground wire at the metal box with no need to bring it to the outlet. A metal 4x4 box would probably be ideal.

If you can find a stud to nail the box to (from its inside; you can drill holes in metal boxes if the holes aren't on a knockout)... then mount the box to the stud. Otherwise they make "old work" boxes designed to mount direct on drywall, however they are not good at resisting the very high insertion force of a NEMA 14-30 outlet.

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  • The dryer that came with the house worked for years. I suspect it linked the ground and the neutral, but I didn't check. // Regarding the Lack of ground GFCI breaker solution -- I'd need to move the uninsulated wire from ground over to the neutral terminal on the outlet, right? Because it has a ground, and has no neutral.
    – Dave X
    Jan 29, 2023 at 6:02
  • Per another comment, I noticed that my current 40A breaker is an issue. (pic added in Q) That's oversize for this NEMA 14-30 outlet, correct?
    – Dave X
    Jan 29, 2023 at 6:34
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    @DaveX 3-wire dryers do not have ground. They have neutral. They need neutral for the 120V loads in the dryer, for motor and controls (which are the same as on a gas fired dryer). If you thought that was ground that is incorrect. The dryer neutral would need to be on the GFCI, yes. The 40A breaker is too large for a NEMA 10-30 or 14-30. Jan 29, 2023 at 8:40
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    @DaveX Yeah I knew it was inherited work. Regardless, a 3-wire dryer feed is hot-hot-neutral no ground. The prior nitwit mis-wired it onto the ground of the 14-30, and then, bridged neutral to ground at the dryer. Don't do that. Jan 29, 2023 at 19:34
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    @DaveX Great news! But remove the neutral-ground bond on the dryer. Follow the dryer instructions for wiring with a 4-wire cord. It's fine for the dryer chassis to be floating; the GFCI is there to make it fine. Feb 3, 2023 at 2:57

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