# Weird dryer 3-wire/4-wire diagram



## mikewillnot (Apr 2, 2013)

Went to convert a Samsung (model DV393ETPAWR/A1) dryer from a 3-wire setup to 4-wire today, and found this diagram. It does not compute. Why on earth would a 4-wire configuration require that the dryer's "ground strap" be connected to the neutral? And, oddly, in the 3-wire diagram it shows the "ground strap" connected to the frame. ????


[addl info: the machine's interior wires, H-H-N-groundstrap, come from within through a piece of flex tubing, and with the exception of the controversial "ground strap," terminate on the top of the terminal bar.


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## Bird dog (Oct 27, 2015)

Do the installation instructions packed with the machine say the same thing? Do they have the blurb saying have a qualified person do this?


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## HackWork (Oct 2, 2009)

That ground strap is connected to the neutral behind the terminal bar.

When you’re using a three wire set up, that ground strap is used to connect the neutral to the frame.

When using a four wire set up, they have you terminate the ground strap on the neutral terminal which cancels it out (since the other end is connected to the neutral). I assume that is just so it doesn’t flop around and touch the metal frame.


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## micromind (Aug 11, 2007)

Obviously, the idiot who made the label is .....well.....an idiot. 

This brings up an interesting question, 110.3(B) plainly requires us to install equipment according to manufacturers instructions. Do we follow the instructions even if they're wrong?


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## HackWork (Oct 2, 2009)

micromind said:


> Obviously, the idiot who made the label is .....well.....an idiot.
> 
> This brings up an interesting question, 110.3(B) plainly requires us to install equipment according to manufacturers instructions. Do we follow the instructions even if they're wrong?


What is wrong about it?


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## HackWork (Oct 2, 2009)

Here's a snip from the manual, different picture but it shows the same thing:









Here's another brand of dryer with the same type of connection:









And here is just a random Whirlpool dryer that I pulled up, the same:









It's just the standard way to do it.

Once that wire is disconnected from the frame, it is no longer the "ground strap", it is the "neutral strap".


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## Dennis Alwon (May 9, 2009)

The 4 wire connection is incorrect. You would not have a ground strap connected to the neutral. The strap would either get disconnected or connected to the equipment grounding conductor of the 10/3 with ground cable.

I would probably disconnect it because I have seen some that are connected to the neutral internally


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## HackWork (Oct 2, 2009)

Dennis Alwon said:


> The 4 wire connection is incorrect. You would not have a ground strap connected to the neutral. The strap would either get disconnected or connected to the equipment grounding conductor of the 10/3 with ground cable.
> 
> I would probably disconnect it because I have seen some that are connected to the neutral internally


It’s only called a ground strap because it used to ground the neutral when it’s attached to the frame. Once you disconnect it from the frame, it’s no longer grounded. It’s attached to the neutral on the other end. Attaching it to the neutral on the terminal strip is just a way to hold it down so it doesn’t flop around and touch the hots or the frame.


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## mikewillnot (Apr 2, 2013)

HackWork said:


> That ground strap is connected to the neutral behind the terminal bar.
> 
> When you’re using a three wire set up, that ground strap is used to connect the neutral to the frame.
> 
> When using a four wire set up, they have you terminate the ground strap on the neutral terminal which cancels it out (since the other end is connected to the neutral). I assume that is just so it doesn’t flop around and touch the metal frame.



So you're saying the ground strap is connected to the neutral somewhere inside the machine? Because it sure isn't at the terminal bar, where I usually see ground straps.


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## HackWork (Oct 2, 2009)

mikewillnot said:


> So you're saying the ground strap is connected to the neutral somewhere inside the machine? Because it sure isn't at the terminal bar, where I usually see ground straps.


Yes, that’s the entire point of it. It connects the neutral to the frame. When you use a four wire cord, you disconnect that strap and connect the ground from the cord to the frame instead.


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## mikewillnot (Apr 2, 2013)

Dennis Alwon said:


> The 4 wire connection is incorrect. You would not have a ground strap connected to the neutral. The strap would either get disconnected or connected to the equipment grounding conductor of the 10/3 with ground cable.
> 
> I would probably disconnect it because I have seen some that are connected to the neutral internally


 There seems to be a consensus that the "ground strap" -- which in no way resembles any ground strap I have ever seen -- is in fact connected to neutral somewhere inside the machine. That's the only scenario where the diagrams make any sense. And suggests that my use of quotation marks around the phrase was appropriate, because it's not a ground strap or a jumper in any commonly understood way. Where I come from, a ground strap is actually a strap, and it goes from the ground lug to the neutral terminal on the terminal strip. And that's the kind of thing that is prohibited from being used with a 4-wire setup. 

I would argue that this diagram may be technically correct, but it is as clear as mud electrically and in terms of the English language. Where I come from, the only time you put a green ground wire on a neutral terminal is with a 3-wire setup.


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## emtnut (Mar 1, 2015)

mikewillnot said:


> There seems to be a consensus that the "ground strap" .......


Doesn't seem to be a consensus, but Hax is right :biggrin:


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## micromind (Aug 11, 2007)

HackWork said:


> What is wrong about it?


If it is indeed true that the manufacturer requires the neutral to be bonded to the frame with a 4 wire cord, then it's wrong. 

But looking at it deeper, it appears that their drawing is indeed correct, just a bit confusing.


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## splatz (May 23, 2015)

It is not a ground strap, it's a neutral jumper. Call it that and it all makes sense :thumbsup: 

It would be a lot more normal to have a ground strap and terminal but it's electrically equivalent, normal, safe as shown in the instructions. Three wire, frame is bonded to neutral; four wire, frame is bonded to EGC. The neutral jumper is landed just so it's not flopping around shorting etc.


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## HackWork (Oct 2, 2009)

micromind said:


> If it is indeed true that the manufacturer requires the neutral to be bonded to the frame with a 4 wire cord, then it's wrong.


Think of where that "ground strap" is coming from. It has to be coming from the neutral, correct? That is why the loose end gets attached to the frame when using a 3-wire cord. It bonds neutral to the frame. So the end we can't see is attached to the neutral.


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## HackWork (Oct 2, 2009)

emtnut said:


> Doesn't seem to be a consensus, but Hax is right :biggrin:


:glasses:


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## Dennis Alwon (May 9, 2009)

HackWork said:


> Yes, that’s the entire point of it. It connects the neutral to the frame. When you use a four wire cord, you disconnect that strap and connect the ground from the cord to the frame instead.


I agree but that is not what the picture is showing. It seems to have the ground strap connected to the neutral in the 4 wire install


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## HackWork (Oct 2, 2009)

Dennis Alwon said:


> I agree but that is not what the picture is showing. It seems to have the ground strap connected to the neutral in the 4 wire install


The ground strap is not a ground strap when it is removed from the frame, the other end of it is connected to the neutral. It is a neutral strap. The loose end also connects to the neutral on the front fo the terminal bar so it doesn't flop around. Both ends are now connected to the neutral. No ground.

Just put some thought into it, where is the other end of that wire connected? You are thinking that is is connected to ground, but why would it be? If the other end of that wire was connected to ground, what would be the point of connecting the loose end to the frame when using a 3-wire cord?


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## CoolWill (Jan 5, 2019)

The picture is correct. That jumper, AKA "ground strap" is permanently connected to the neutral terminal on the back of the block. The free end either connects to the frame, as in the 3-wire pic, or it loops back to the neutral, as in the 4-wire pic.

With the 4-wire cord, it isn't necessary to actually connect it to the neutral since it is already connected on the other end. They show that so you won't just leave it flopping around.


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## HackWork (Oct 2, 2009)

CoolWill said:


> With the 4-wire cord, it isn't necessary to actually connect it to the neutral since it is already connected on the other end. They show that so you won't just leave it flopping around.


I have always cut the end off and taped it up. Attaching it to the front neutral terminal is a better idea incase they ever bring the dryer somewhere that has a 3 prong outlet.


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## Incognito (Apr 14, 2019)

I assume that if you have an existing receptacle you are allowed to connect a new dryer without the ground (3 wire), but if your installing new, must you use a conductor and receptacle with a ground (4 wire)?


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## HackWork (Oct 2, 2009)

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Incognito said:


> I assume that if you have an existing receptacle you are allowed to connect a new dryer without the ground (3 wire), but if your installing new, must you use a conductor and receptacle with a ground (4 wire)?


Yes, exactly. We have a system throughout our country in which the customer purchases a cord installation package when they buy the dryer. The delivery man will install the proper cord on the machine when he places the unit. This way they could match the three prong or four prong outlet.


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## CoolWill (Jan 5, 2019)

HackWork said:


> ```
> 
> ```
> Yes, exactly. We have a system throughout our country in which the customer purchases a cord installation package when they buy the dryer. The delivery man will install the proper cord on the machine when he places the unit. This way they could match the three prong or four prong outlet.


That system wouldn't work in Canada. As soon as the driver installed the cord, someone would use the unlicensed snitch line to bury him.


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## Incognito (Apr 14, 2019)

CoolWill said:


> That system wouldn't work in Canada. As soon as the driver installed the cord, someone would use the unlicensed snitch line to bury him.


LOL.

There are many things that do not require a permit or a license, like working on appliances. 

Now if he tried to run a new circuit........BOOM! Jail time! JK


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## Dennis Alwon (May 9, 2009)

Not sure why they call it a ground strap at both places. My recollection was that the strap that is on the neutral bonded the frame on the inside somewhere and wasn't connected to the neutral at the other end. I always disconnected it and everything worked so it does not need to be connected. Perhaps it is fine to leave it- IDK without seeing it and testing it

There was always another wire (neutral) that was internally connected to the neutral screw. It is hard to know without seeing the unit.


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## HackWork (Oct 2, 2009)

Dennis Alwon said:


> Not sure why they call it a ground strap at both places. My recollection was that the strap that is on the neutral bonded the frame on the inside somewhere and wasn't connected to the neutral at the other end. I always disconnected it and everything worked so it does not need to be connected. Perhaps it is fine to leave it- IDK without seeing it and testing it
> 
> There was always another wire (neutral) that was internally connected to the neutral screw. It is hard to know without seeing the unit.


Dennis, I forbid you from ever working on an electric dryer again until you figure this out. What we see in the picture makes perfect sense.


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## Dennis Alwon (May 9, 2009)

HackWork said:


> Dennis, I forbid you from ever working on an electric dryer again until you figure this out. What we see in the picture makes perfect sense.


It makes sense to you--- I still have questions on it however it would take me a minute to figure it out at the dryer. 

But don't worry I don't do much work anymore. After burning down 3 homes they prefer I stay home...:biggrin:


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## HackWork (Oct 2, 2009)

Dennis Alwon said:


> It makes sense to you--- I still have questions on it however it would take me a minute to figure it out at the dryer.


Just think about it. Look at the 3-wire cord configuration. It has that jumper come out from behind the terminal and connect to the frame. That is bonding the neutral to the frame. Therefore, that wire is attached to the neutral behind the terminal. You follow?



> But don't worry I don't do much work anymore. After burning down 3 homes they prefer I stay home...:biggrin:


:vs_laugh::biggrin:


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## CoolWill (Jan 5, 2019)

HackWork said:


> Just think about it. Look at the 3-wire cord configuration. It has that jumper come out from behind the terminal and connect to the frame. That is bonding the neutral to the frame. Therefore, that wire is attached to the neutral behind the terminal. You follow?
> 
> 
> 
> :vs_laugh::biggrin:


1.5 seconds of a YouTube video of a guy with a continuity meter would fix it all.


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## splatz (May 23, 2015)

Dennis Alwon said:


> Not sure why they call it a ground strap at both places.



Probably because the Chinese prison laborer that wrote the manual did the best he could using the free online version of the NEC and Google Translate.


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## MechanicalDVR (Dec 29, 2007)

Dennis Alwon said:


> It makes sense to you--- I still have questions on it however it would take me a minute to figure it out at the dryer.
> 
> But don't worry I don't do much work anymore. *After burning down 3 homes they prefer I stay home*...:biggrin:



If you can't do, inspect......or rewrite code...



:vs_laugh::vs_laugh::vs_laugh:


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## MechanicalDVR (Dec 29, 2007)

Maybe this is more clear to explain what Hacks has been trying to explain all along.


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## mikewillnot (Apr 2, 2013)

CoolWill said:


> The picture is correct. That jumper, AKA "ground strap" is permanently connected to the neutral terminal on the back of the block. The free end either connects to the frame, as in the 3-wire pic, or it loops back to the neutral, as in the 4-wire pic.
> 
> With the 4-wire cord, it isn't necessary to actually connect it to the neutral since it is already connected on the other end. They show that so you won't just leave it flopping around.


[OP] For the diagram I posted, your first paragraph would be incorrect. The so- called ground strap is not permanently connected to the neutral terminial on the back of the block, either in the picture or in reality. The picture is unclear as to the origin of the green/yellow wire it calls a "ground strap" and in the actual machine, that wire emerges from inside the machine via a piece of flex tubing, along with the other main power conductors. 

Having said that, your actual electrical analysis, and your point, does seem to be correct.


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## HackWork (Oct 2, 2009)

mikewillnot said:


> [OP] For the diagram I posted, your first paragraph would be incorrect. The so- called ground strap is not permanently connected to the neutral terminial on the back of the block, either in the picture or in reality. The picture is unclear as to the origin of the green/yellow wire it calls a "ground strap" and in the actual machine, that wire emerges from inside the machine via a piece of flex tubing, along with the other main power conductors.
> 
> Having said that, your actual electrical analysis, and your point, does seem to be correct.


This is getting ridiculous.

That wire *IS* connected to the neutral terminal in BOTH the picture and real life.

There are things that we know, and we have to use that when viewing a diagram. We know that the wire in the image bonds neutral to ground, so if the exposed end connects to the grounded frame, the other end HAS TO connect to the neutral. The picture is correct.

As for where the wire actually terminates, it does not matter, we know that it is "connected to the neutral terminal on the back of the block", whether directly or indirectly. It makes no difference which.


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## emtnut (Mar 1, 2015)

mikewillnot said:


> [OP] For the diagram I posted, your first paragraph would be incorrect. The so- called ground strap is not permanently connected to the neutral terminial on the back of the block, either in the picture or in reality. The picture is unclear as to the origin of the green/yellow wire it calls a "ground strap" and in the actual machine, that wire emerges from inside the machine via a piece of flex tubing, along with the other main power conductors.
> 
> Having said that, your actual electrical analysis, and your point, does seem to be correct.


This is one of those situations where you just pull out your meter, and see where the continuity is ... It's what @Dennis Alwon was saying when he said he would know within a minute when he is there.


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## fmwowol (Aug 11, 2019)

Do the installation instructions packed with the machine say the same thing? Do they have the blurb saying have a qualified person do this?


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## glen1971 (Oct 10, 2012)

Bird dog said:


> Do the installation instructions packed with the machine say the same thing? Do they have the blurb saying have a qualified person do this?





fmwowol said:


> Do the installation instructions packed with the machine say the same thing? Do they have the blurb saying have a qualified person do this?


 @Bird dog look familiar? :vs_laugh:


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## Bird dog (Oct 27, 2015)

Quote:
Originally Posted by *Bird dog*  
_Do the installation instructions packed with the machine say the same thing? Do they have the blurb saying have a qualified person do this?_

Quote:
Originally Posted by *fmwowol*  
_Do the installation instructions packed with the machine say the same thing? Do they have the blurb saying have a qualified person do this?_



glen1971 said:


> @*Bird dog* look familiar? :vs_laugh:


Somebody owes me a royalty check.


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## HackWork (Oct 2, 2009)

I didn't want to bump this thread at the time, but since it's already been done I will post this.

I have installed 2 dryer outlets and cord on the dryer since this thread. In both situations, instead of just cutting the end off of the ground jumper or taping it up and shoving it into the back (both bad ideas, IMO), I have landed it on the neutral terminal. It works very well and I will continue to do it this way.


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## MechanicalDVR (Dec 29, 2007)

HackWork said:


> I didn't want to bump this thread at the time, but since it's already been done I will post this.
> 
> I have installed 2 dryer outlets and cord on the dryer since this thread. In both situations, instead of just cutting the end off of the ground jumper or taping it up and shoving it into the back (both bad ideas, IMO), I have landed it on the neutral terminal. It works very well and I will continue to do it this way.



A permanent connection.

Only way to fly bro!


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## Norcal (Mar 22, 2007)

HackWork said:


> I didn't want to bump this thread at the time, but since it's already been done I will post this.
> 
> I have installed 2 dryer outlets and cord on the dryer since this thread. In both situations, instead of just cutting the end off of the ground jumper or taping it up and shoving it into the back (both bad ideas, IMO), I have landed it on the neutral terminal. It works very well and I will continue to do it this way.





That is the way I have always done it in case it has to be changed back to 3-wire should it be moved to a new location.


See anything wrong? :devil3: It was sitting in the parking area of a scrap yard, where it had been dumped over a weekend, it had been sitting for a while before I took a second look & noticed how the connectors were landed, all I can say is that hope nobody was hurt.


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## readydave8 (Sep 20, 2009)

" It was sitting in the parking area of a scrap yard"

yup they scrapped it because it not only wouldn't dry clothes but also shocks!


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## RRF (Nov 5, 2016)

Did the cord end have battle scars on it?


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## Norcal (Mar 22, 2007)

RRF said:


> Did the cord end have battle scars on it?



Never looked at it, it has long since been baled into a cube & it may have already been turned into rebar & used in a project. :biggrin:


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