Adding a separate ground wire for dryer.

Coppersmith

Senior Member
Location
Tampa, FL, USA
I know there must be an existing post on this subject, but I can't find it so bear with me.

I have a client with a three wire dryer recep. Due the wall construction it's not possible to get a 10/3 NM over there to change it to a 4-wire recep (without massive demo). The dryer is sitting right next to the water heater which is properly wired with 10/2 NM.

Can I tap the WH ground wire and run it over to the 4-wire dryer recep? (code reference please)

Can I ground using the water pipe of the washer? (code reference please) I have to check, but i believe the house has all copper piping.
 

kwired

Electron manager
Location
NE Nebraska
I know there must be an existing post on this subject, but I can't find it so bear with me.

I have a client with a three wire dryer recep. Due the wall construction it's not possible to get a 10/3 NM over there to change it to a 4-wire recep (without massive demo). The dryer is sitting right next to the water heater which is properly wired with 10/2 NM.

Can I tap the WH ground wire and run it over to the 4-wire dryer recep? (code reference please)

Can I ground using the water pipe of the washer? (code reference please) I have to check, but i believe the house has all copper piping.
Do you need to change it to 4 wire? Did you move the receptacle or extend the supply end of the circuit? Was fed from service panel and it got converted to feeder supplied panel?
 

wwhitney

Senior Member
Location
Berkeley, CA
no - 250.132(C)
(2014) 250.130(C)(4) explicitly allows using the 10/2 NM EGC if it originates in the same panel as the dryer receptacle circuit. And 300.3(B)(2) allows running the grounding conductor outside of the cable serving the dryer receptacle in accordance with 250.130(C) for "certain existing installations."

Cheers, Wayne
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Electrician
(2014) 250.130(C)(4) explicitly allows using the 10/2 NM EGC if it originates in the same panel as the dryer receptacle circuit. And 300.3(B)(2) allows running the grounding conductor outside of the cable serving the dryer receptacle in accordance with 250.130(C) for "certain existing installations."

Cheers, Wayne
That would be correct if under the 2014 and later. We are under the 2008 (for now) and that's what I was referencing.
 

Coppersmith

Senior Member
Location
Tampa, FL, USA
Do you need to change it to 4 wire? Did you move the receptacle or extend the supply end of the circuit? Was fed from service panel and it got converted to feeder supplied panel?
We are doing a service change with an upgrade from 100 to 200 amps. The AHJ requires dryer and range wiring be brought up to current code unless change is same size. The house appears to have been recently rewired except for the dryer circuit.

That would be correct if under the 2014 and later. We are under the 2008 (for now) and that's what I was referencing.
We are under 2014.
 

Coppersmith

Senior Member
Location
Tampa, FL, USA
(2014) 250.130(C)(4) explicitly allows using the 10/2 NM EGC if it originates in the same panel as the dryer receptacle circuit. And 300.3(B)(2) allows running the grounding conductor outside of the cable serving the dryer receptacle in accordance with 250.130(C) for "certain existing installations."
Thank you, this appears to be what I need. I'm unclear if 300.3(B)(2) is saying the EGC has to be next to the cable or raceway (on the outside) or if the EGC can take an entirely different route. In my case, the EGC would be running horizontally from WH to dryer whereas the circuit for both of these are vertical from the ceiling. Also does the EGC have to be protected with conduit or inside the wall or can I run it on the surface of the wall unprotected?
 

JFletcher

Senior Member
Location
Williamsburg, VA
We are doing a service change with an upgrade from 100 to 200 amps. The AHJ requires dryer and range wiring be brought up to current code unless change is same size. The house appears to have been recently rewired except for the dryer circuit.



We are under 2014.
Unless the exception for 250.140 has been changed for the 2014 code cycle, or the conditions are not met, your inspector is incorrect in forcing those circuits to be upgraded.
 

kwired

Electron manager
Location
NE Nebraska
Unless the exception for 250.140 has been changed for the 2014 code cycle, or the conditions are not met, your inspector is incorrect in forcing those circuits to be upgraded.
I agree NEC doesn't require the change - but I think he is saying they have a local rule that says it must be changed if the service is upgraded. IMO, dumb rule. NEC allowing these three wire circuits (at least as long as they did) was dumb as well though. This is a little like buying an older car but a local authority says you must equip it with current model year required safety features or you can't drive it on a public road.
 

JFletcher

Senior Member
Location
Williamsburg, VA
He might want to see if this is actually a local amendment vs something the inspector "wants"
Agreed. And kwired, could be, tho many use AHJ and inspector interchangeably when they really arent. I see nothing wrong with using three wire ranges and dryers, within the provision of 250.140. There are literally millions of homes that have them installed, with aluminum wire SE cable) at that, with no problems.

Here, if you move the receptacle, it is no longer "existing", and then you don't meet 250.140. Changing a main panel into a subpanel would require a 4 wire feed to both ranges and dryers.

Unless, like electrofelon wrote, this is a local amendment in the original posters area, I would definitely fight this one.
 

Coppersmith

Senior Member
Location
Tampa, FL, USA
I agree NEC doesn't require the change - but I think he is saying they have a local rule that says it must be changed if the service is upgraded. IMO, dumb rule. NEC allowing these three wire circuits (at least as long as they did) was dumb as well though. This is a little like buying an older car but a local authority says you must equip it with current model year required safety features or you can't drive it on a public road.
He might want to see if this is actually a local amendment vs something the inspector "wants"
Agreed. And kwired, could be, tho many use AHJ and inspector interchangeably when they really arent. I see nothing wrong with using three wire ranges and dryers, within the provision of 250.140. There are literally millions of homes that have them installed, with aluminum wire SE cable) at that, with no problems.

Here, if you move the receptacle, it is no longer "existing", and then you don't meet 250.140. Changing a main panel into a subpanel would require a 4 wire feed to both ranges and dryers.

Unless, like electrofelon wrote, this is a local amendment in the original posters area, I would definitely fight this one.
Yes, this is a local rule. I've never actually spoken to the chief electrical inspector about it, but multiple underlings have said this is true. I think I will have to call and ask the chief just to be sure.
 
Top