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Samsung dryer, model DV422EWHDWR/AA

picture of how the dryer cable was before I tinkered

picture of dryer cable setup after some tinkering

My Dryer has a 3-prong cable, I need to upgrade to 4-prong.

I have TWO GREEN wires here, which is something I cannot find mentioned anywhere else. I reckon that one of these corresponds to the usual solid metal tab connecting the terminal assembly to the dryer’s metal body, and the other corresponds to the (usually white) connection that “pseudo-grounds” from the neutral connection, but I‘m uncertain, don’t want to die, and don’t want to destroy the dryer or the house.

I think I’m supposed to remove the smaller green wire, and connect both the white and the thicker green wire to the center connection on the terminal assembly.

Can anyone offer me wisdom in this matter? If this question is a duplicate, I cannot find any similar question especially regarding the ostensibly mislabelled and extra green wires.

(The image descriptions didn’t appear in the post like I thought - the first image is a picture of how the dryer cable was arranged before I did anything, the second image is of my preliminary tinkering, now I believe that thick green wire should connect to the center terminal with the white cable.)

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    Hello, and welcome to Home Improvement. What make/model is the dryer, and what does the installation manual say? And, you should probably take our tour so you'll know how best to participate here. – Daniel Griscom Oct 6 '19 at 22:01
  • Thank you thank you! I’ll edit with make/model, but the manual doesn’t address mislabelled wires or the additional one at all that I can find. Model DV422EWHDWR/AA. There’s an additional supplemental electrical manual I have a hard copy of that references a SINGLE green/yellow wire in 4 prong setup, but neither the 3-prong nor 4-prong diagrams reference all five of the wires I discovered my dryer setup with while it was still in 3-prong setup. – Shaun Miller Oct 6 '19 at 22:10
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    Can you perform a continuity check from the neutral screw on the terminal block to the ring lug on the skinny (lower) grounding jumper, with the dryer unplugged of course? That'll tell us something about where it goes, at least... – ThreePhaseEel Oct 7 '19 at 4:14
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    +1 for "I‘m uncertain, don’t want to die, and don’t want to destroy the dryer or the house." – Wayne Conrad Oct 7 '19 at 20:54
  • I'd bet that the second green wire is indeed an additional ground. Both positions have the same "Ground" symbol. What the pictures don't show is where the thick and thin green wires were connected pre rewiring. Be careful that the thick green wire isn't shorted to the neutral inside the washer, behind the black visible block; if that were so you'd indeed be negating the point of upgrading to 4 wire. Normally 3-wire 220 is two hot's (on opposing phases) and ground; neutral is omitted. So now your new wire would be neutral. The machine was probably installed neutral to gnd, so check that first. – Andy Zarzycki Oct 8 '19 at 15:03
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No, No, No! In this day and age you never hook green (ground) wires to white (neutral) wires. That's why you're going to a 4 prong from a 3 prong... so you can separate them. You need to determine where those green wires are hooked up that appear to go behind the terminal block to make sure they are not jumped to the neutral, white wire. If they are, disconnect them and just remove them completely as they are not needed because of the new ground wire in the plug.

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    I appreciate your input so much, that’s the very issue here: it’s abundantly clear that NEITHER of these wires should have been green in the first place, yet there the freaking stinkers were, placed there by Best Buy’s professional installation six years ago. XD. So, I might have to hire a professional for this, I’ve been trying to take apart the chassis enough to see where these two greens are actually going so I can know which one to hook to the white center terminal, but I can’t seem to get there - even to properly remove or disconnect them entirely. Again, greatly appreciate your input :) – Shaun Miller Oct 7 '19 at 2:10
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    Get a multimeter (or in a pinch, a continuity tester), that will tell you which is hooked where (simply touch one lead to a wire in question and one to the white, if it beeps/lights/zeroes out/etc, you have an electrical connection). – Doktor J Oct 7 '19 at 5:59
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    I’ve been jonesing for an excuse to get a multimeter for some months now, I may take this as a good opportunity to take that plunge. Thanks for your input, too, Doktor J! I’ll report back once I’ve done that. – Shaun Miller Oct 7 '19 at 17:22
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Neutral is not ground. You must always keep them separate. (even in the main panel; however there, you will have a neutral-ground equipotential bond, the only one in the house).

So a 4-wire connection does exactly what you'd think: neutral to neutral and ground to ground.

However, before grounding, it was universal to run a 3-wire connection to dryers and ranges. The appliance industry did not want to deal with change, because they feared they'd lose a lot of business if everyone had to rewire their house to buy a new appliance. So they convinced NFPA to cut them an exception, where the appliance chassis is "grounded" to neutral. Anywhere else, this is called "bootlegging ground".

So a 3-wire connection has two parts to it: The three wires connecting as you'd expect, and also a jumper between neutral and ground.

NEC 110.3B requires you to follow the instructions and labeling when installing an appliance. The instructions will certainly include a procedure to convert from 4-prong to 3-prong or vice versa. Look for that neutral-ground jumper, and remove it. On your dryer, I believe the green/yellow wire actually is attached to the neutral terminal at its other end. Your particular instructions (page 17 part 8) instruct to "loop back" the green/yellow ground wire back to the neutral terminal, rendering it inert. (Even though it looks really weird).

The small ground wire you removed appears to be out-of-scope of the instructions I mentioned. I would put it back.

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    He's run into a situation where there appears to be an extra jumper on his unit that's not discussed by the instruction manual... – ThreePhaseEel Oct 7 '19 at 4:13
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    @ShaunMiller yeah, the little one that is outside the attachment area seems to be out-of-scope of the documentation, so I am sure it's unrelated. I'm shaking my head at the green/yellow wire. However, UL approved it, so it clearly is coming from them. UL would certainly send them back to the showers to use a white or gray wire if they wanted it colored that. Yellow without green is just another hot color in North America; I use it for travelers. – Harper - Reinstate Monica Oct 7 '19 at 17:25
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    @Shaun: inspired by this answer to your question, I took another look at a 3-prong to 4-prong conversion I did myself on my dryer a month or so ago, and like you found a jumper from ground to neutral. In my case, it was relatively simple to disconnect the jumper (after my conversion, it shared a screw with the ground from the four-conductor wire from the new plug) and then use a continuity tester to verify that after disconnection, all of the ground connections in the dryer only went to ground, and all of the neutral connections only went to neutral. ... – Peter Duniho Oct 8 '19 at 0:07
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    ... The hardest part was finding the hidden screws that let me open up the control panel on top of the dryer so I could take a look at where all the wires went (no doubt your Samsung will be completely different in configuration). – Peter Duniho Oct 8 '19 at 0:07
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    @PeterDuniho Well done finding that. Yeah, as long as you have no continuity between N and G (measure at the NEMA 14 plug), you're all set. – Harper - Reinstate Monica Oct 8 '19 at 3:07
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It sounds like you're on the right track. There are several green wires in the pictures, so I took the second picture and labeled them.

Annotated copy of dryer cable wiring

Small green wire (#1)

This one is bolted to the dryer's case in the first picture, but loose in the second one. It's meant to connect internal equipment (probably the timer/computer) to the case so it has a ground. It stays the same whether you have a 3- or 4-prong power cable, so you'll need to bolt it back in place like it was in the first picture.

Power cable wire (#2)

This is the green wire that comes out of your power cable. This one takes any electricity that happens to be in the case (say, from wire #1) and takes it safely away to ground. It just needs to be screwed to the dryer case, likely next to the little ground symbol. It looks like it's already there in the second picture, so you shouldn't need to worry about this one.

Thick green wire inside dryer (#3)

This one is bolted to the left of the terminal block in your second picture. I suspect it's a ground strap, which connects the dryer's case to the neutral terminal.

You can confirm this by examining the back of the terminal block. If you remove the two outside screws on the block, you should be able to pull the block out far enough to see its back. If you then follow wire #3, you should see the other end permanently bonded to the back of the neutral terminal. If you do, that's your ground strap.

If it doesn't look like a ground strap, take some more pictures and edit them into your question so we can try to figure out what it really is. But I'm very willing to bet it's a ground strap.

To deal with the ground strap, just connect its loose end to the same screw as the neutral wire from your power cord. This should be the same terminal as the other end of the wire is connected to. It might look a little weird having a ground wire connected to the neutral terminal, but since both ends are attached to the same place, it will effectively make the ground strap do nothing.

With that done, your dryer should be properly grounded and its ground and neutral should be properly isolated from one another.

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    Dryer bonding jumpers are generally captive/nonremovable -- landing their movable end on the neutral screw is generally what the instructions call for. – ThreePhaseEel Oct 8 '19 at 0:37
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    @ThreePhaseEeel: I'm not sure I understand your comment. Do you just mean I used the wrong terminology? Or did I make a mistake about how to wire the dryer? Mains electricity is dangerous, so I'd like to get it right. – Mirinth Oct 8 '19 at 0:44
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    Hello, and welcome to Home Improvement. Thanks for the answer; keep 'em coming. And, you should probably take our tour so you'll know how best to contribute here. – Daniel Griscom Oct 8 '19 at 0:45
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    @Mirinth it means that you basically can't "remove the jumper" the way your answer describes – ThreePhaseEel Oct 8 '19 at 1:07
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    @ThreePhaseEeel Ah, I see now. Thanks for the catch. I edited to fix that. – Mirinth Oct 8 '19 at 2:41
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I believe Mirinth's answer is correct, the thick green/yellow stripe wire is a ground strap and the smaller green wire is an electronics ground. Here's why:

I have a Samsung unit, model DVE52M7750W, with a similar panel. All the wiring in this unit's panel matches yours except the ground strap is a white wire, instead of green/yellow stripe and there is an explicit wiring diagram labeling it as a ground strap. On this unit, the ground strap is bolted to the same post as the neutral, as one would expect. The small green wire isn't implicated in the 4-prong wiring at all and is left unmolested.

Bear in mind, appearances may deceive: they might look a lot alike on the outside, but it's what's on the inside that matters. The wiring diagram in an online copy of the manual suggest to me your unit and mine should be wired similarly, but it'd be a good idea to double check.

maker's plate wiring diagram wiring as installed installation instructions for this model

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