Weird dryer 3-wire/4-wire diagram - Electrician Talk - Professional Electrical Contractors Forum
CLICK HERE AND JOIN OUR COMMUNITY TODAY, IT'S FREE!
Go Back   Electrician Talk - Professional Electrical Contractors Forum > Electrical Trade Topics > Residential Electrical Forum


Like Tree25Likes
Reply
Thread Tools Display Modes
Unread 07-10-2019, 06:18 PM   #1
Senior Member
 
Join Date: Apr 2013
Location: Rochester, NY
Posts: 439
Rewards Points: 697
Default Weird dryer 3-wire/4-wire diagram

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.



Weird dryer 3-wire/4-wire diagram-img_20190710_152736.jpg

Last edited by mikewillnot; 07-10-2019 at 06:36 PM.
mikewillnot is offline   Reply With Quote
Join Contractor Talk

Join the #1 Electrician Forum Today - It's Totally Free!

ElectricianTalk.com - Are you a Professional Electrical Contractor? If so we invite you to join our community and see what it has to offer. Our site is specifically designed for you and it's the leading place for electricians to meet online. No homeowners asking DIY questions. Just fellow tradesmen who enjoy talking about their business, their trade, and anything else that comes up. No matter what your specialty is you'll find that ElectricianTalk.com is a great community to join. Best of all it's totally free!

Join ElectricianTalk.com - Click Here JOIN FOR FREE


Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. ElectricianTalk.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any construction or remodeling task!

Sponsored Links
Advertisement
 
Unread 07-10-2019, 06:55 PM   #2
Senior Member
 
Bird dog's Avatar
 
Join Date: Oct 2015
Location: South East US
Posts: 4,727
Rewards Points: 1,242
Default

Do the installation instructions packed with the machine say the same thing? Do they have the blurb saying have a qualified person do this?
__________________
Popcorn munching forum observer
"The supreme art of war is to subdue the enemy without fighting." Sun Tzu
Bird dog is online now   Reply With Quote
Unread 07-10-2019, 06:59 PM   #3
Senior Member
 
HackWork's Avatar
 
Join Date: Oct 2009
Location: -
Posts: 32,174
Rewards Points: 1,499
Default

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.
readydave8, JoeSparky and Bird dog like this.
__________________
There are 2 types of electrician... Those who knowingly break code, and those who lie about it.
HackWork is online now   Reply With Quote
Sponsored Links
Advertisement
 
Unread 07-10-2019, 07:15 PM   #4
Bilge Rat
 
Join Date: Aug 2007
Location: Fernley, Nevada (near Reno)
Posts: 6,413
Rewards Points: 2,438
Default

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?
micromind is online now   Reply With Quote
Unread 07-10-2019, 07:19 PM   #5
Senior Member
 
HackWork's Avatar
 
Join Date: Oct 2009
Location: -
Posts: 32,174
Rewards Points: 1,499
Default

Quote:
Originally Posted by micromind View Post
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?
__________________
There are 2 types of electrician... Those who knowingly break code, and those who lie about it.
HackWork is online now   Reply With Quote
Unread 07-10-2019, 07:36 PM   #6
Senior Member
 
HackWork's Avatar
 
Join Date: Oct 2009
Location: -
Posts: 32,174
Rewards Points: 1,499
Default

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

Weird dryer 3-wire/4-wire diagram-screen-shot-2019-07-10-7.30.38-pm.png

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

Weird dryer 3-wire/4-wire diagram-screen-shot-2019-07-10-7.32.00-pm.png

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

Weird dryer 3-wire/4-wire diagram-screen-shot-2019-07-10-7.35.14-pm.png

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".
__________________
There are 2 types of electrician... Those who knowingly break code, and those who lie about it.
HackWork is online now   Reply With Quote
Unread 07-10-2019, 07:57 PM   #7
Moderator

 
Dennis Alwon's Avatar
 
Join Date: May 2009
Location: Chapel Hill, NC
Posts: 21,005
Rewards Points: 1,078
Default

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
__________________
They say I shot a man named Gray and took his wife to Italy
She inherited a million bucks and when she died it came to me
I can't help it if I'm lucky
Dennis Alwon is online now   Reply With Quote
Unread 07-10-2019, 08:02 PM   #8
Senior Member
 
HackWork's Avatar
 
Join Date: Oct 2009
Location: -
Posts: 32,174
Rewards Points: 1,499
Default

Quote:
Originally Posted by Dennis Alwon View Post
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.
__________________
There are 2 types of electrician... Those who knowingly break code, and those who lie about it.
HackWork is online now   Reply With Quote
Unread 07-10-2019, 08:07 PM   #9
Senior Member
 
Join Date: Apr 2013
Location: Rochester, NY
Posts: 439
Rewards Points: 697
Default

Quote:
Originally Posted by HackWork View Post
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.
mikewillnot is offline   Reply With Quote
Unread 07-10-2019, 08:09 PM   #10
Senior Member
 
HackWork's Avatar
 
Join Date: Oct 2009
Location: -
Posts: 32,174
Rewards Points: 1,499
Default

Quote:
Originally Posted by mikewillnot View Post
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.
MechanicalDVR and circuitman1 like this.
__________________
There are 2 types of electrician... Those who knowingly break code, and those who lie about it.
HackWork is online now   Reply With Quote
Unread 07-10-2019, 08:10 PM   #11
Senior Member
 
Join Date: Apr 2013
Location: Rochester, NY
Posts: 439
Rewards Points: 697
Default

Quote:
Originally Posted by Dennis Alwon View Post
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.
splatz likes this.

Last edited by mikewillnot; 07-10-2019 at 08:36 PM.
mikewillnot is offline   Reply With Quote
Unread 07-10-2019, 10:08 PM   #12
Band Member
 
emtnut's Avatar
 
Join Date: Mar 2015
Location: Eastern Ontario
Posts: 5,639
Rewards Points: 652
Default

Quote:
Originally Posted by mikewillnot View Post
There seems to be a consensus that the "ground strap" .......
Doesn't seem to be a consensus, but Hax is right
__________________
_____________________________________
Your Mother was a hamster, and your father smells of Elderberries. ... Now go away, or I shall taunt you a second time
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
emtnut is online now   Reply With Quote
Unread 07-10-2019, 11:51 PM   #13
Bilge Rat
 
Join Date: Aug 2007
Location: Fernley, Nevada (near Reno)
Posts: 6,413
Rewards Points: 2,438
Default

Quote:
Originally Posted by HackWork View Post
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.
micromind is online now   Reply With Quote
Unread 07-11-2019, 05:16 AM   #14
Hackenschmidt
 
splatz's Avatar
 
Join Date: May 2015
Location: Parts Unknown
Posts: 7,996
Rewards Points: 3,394
Default

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

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.
__________________
Everything Should Be Made as Simple as Possible, But Not Simpler

Last edited by splatz; 07-11-2019 at 05:20 AM.
splatz is online now   Reply With Quote
Unread 07-11-2019, 07:21 AM   #15
Senior Member
 
HackWork's Avatar
 
Join Date: Oct 2009
Location: -
Posts: 32,174
Rewards Points: 1,499
Default

Quote:
Originally Posted by micromind View Post
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.
Bird dog likes this.
__________________
There are 2 types of electrician... Those who knowingly break code, and those who lie about it.
HackWork is online now   Reply With Quote
Unread 07-11-2019, 07:21 AM   #16
Senior Member
 
HackWork's Avatar
 
Join Date: Oct 2009
Location: -
Posts: 32,174
Rewards Points: 1,499
Default

Quote:
Originally Posted by emtnut View Post
Doesn't seem to be a consensus, but Hax is right
__________________
There are 2 types of electrician... Those who knowingly break code, and those who lie about it.
HackWork is online now   Reply With Quote
Unread 07-11-2019, 07:24 AM   #17
Moderator

 
Dennis Alwon's Avatar
 
Join Date: May 2009
Location: Chapel Hill, NC
Posts: 21,005
Rewards Points: 1,078
Default

Quote:
Originally Posted by HackWork View Post
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
__________________
They say I shot a man named Gray and took his wife to Italy
She inherited a million bucks and when she died it came to me
I can't help it if I'm lucky
Dennis Alwon is online now   Reply With Quote
Unread 07-11-2019, 07:27 AM   #18
Senior Member
 
HackWork's Avatar
 
Join Date: Oct 2009
Location: -
Posts: 32,174
Rewards Points: 1,499
Default

Quote:
Originally Posted by Dennis Alwon View Post
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?
__________________
There are 2 types of electrician... Those who knowingly break code, and those who lie about it.

Last edited by HackWork; 07-11-2019 at 09:48 AM.
HackWork is online now   Reply With Quote
Unread 07-11-2019, 07:50 AM   #19
Senior Member
 
CoolWill's Avatar
 
Join Date: Jan 2019
Location: SC
Posts: 1,699
Rewards Points: 1,678
Default

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.
splatz likes this.
__________________
I'm With Her! Hillary 2016
CoolWill is offline   Reply With Quote
Unread 07-11-2019, 08:00 AM   #20
Senior Member
 
HackWork's Avatar
 
Join Date: Oct 2009
Location: -
Posts: 32,174
Rewards Points: 1,499
Default

Quote:
Originally Posted by CoolWill View Post
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.
__________________
There are 2 types of electrician... Those who knowingly break code, and those who lie about it.
HackWork is online now   Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 09:46 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.1
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Our Pro Sites Network
ContractorTalk.com | DrywallTalk.com | HVACSite.com | PaintTalk.com | PlumbingZone.com | RoofingTalk.com