Is a 10-2 conducutor acceptable for a Clothes Dryer?

[anothaparson]

My question is regarding clothes dryer circuits and if we are now required by NEC to run a 10-3 MC cable or 10-2 MC conductor cable still acceptable? I've added MC because I wil be surface mounting and not burying the cable. The reason i'm asking is because i've already run 10-2 MC and now i'm worried that i ran the wrong cable. Thank you in advance for any responses.

 

[guschash]

It's 10-3 but I can't find it right now . If the dryer is the older 3-wire one you should be ok. I alway pull 10-3 so if in the future if HO get newer model I all set and don't have to pull new wire.

 

[templdl]

My question is regarding clothes dryer circuits and if we are now required by NEC to run a 10-3 MC cable or 10-2 MC conductor cable still acceptable? I've added MC because I wil be surface mounting and not burying the cable. The reason i'm asking is because i've already run 10-2 MC and now i'm worried that i ran the wrong cable. Thank you in advance for any responses.

I'm personally intrigued as to why you have asked this question but never the less we welcome your question. It is not my intention to talk down to you but I have to establish first that you are a qualified person who has an electrical background who has knowledge of safe electrical practices and procedures?
Electric cloth driers quite commonly had devices that are powered 120v such as the motor and the control as well as relying of various heat setting which may be powered in part by just 120v or 240v. As such it is required to have a neutral which would require #10/3 w/grd. But you didn't say why you selected #10. It most likely will be #10 but without knowing the load the drier is rated for it would be foolish to agree that it will be a #10.

 

[bob]

Most electric dryers have 240 v heating elements, 120 volt control panel and 120 volt motor that turns the drum.
If this is what you have, then you would need 3 # 10 cu + egc. You need to check to see if MC is allowed to be used as the egc.
Does this answer your question? The MFG should have information regarding the requirements.
I was late posting behind templdl and gus.

 

[480sparky]

If memory serves, 10/2 was never legal.

 

[ceb58]

Look in your code book at 250.140 (2008) also read the exceptions

 

[infinity]

My question is regarding clothes dryer circuits and if we are now required by NEC to run a 10-3 MC cable or 10-2 MC conductor cable still acceptable? I've added MC because I wil be surface mounting and not burying the cable. The reason i'm asking is because i've already run 10-2 MC and now i'm worried that i ran the wrong cable. Thank you in advance for any responses.

Simple answer, on a new standard dryer installation you need 10/3.

 

[anothaparson]

Most electric dryers have 240 v heating elements, 120 volt control panel and 120 volt motor that turns the drum.
If this is what you have, then you would need 3 # 10 cu + egc. You need to check to see if MC is allowed to be used as the egc.
Does this answer your question? The MFG should have information regarding the requirements.
I was late posting behind templdl and gus.

I'm going to rip the cable out eat the cost of my mistake and purchase the correct cable 10-3 MC which has an Equipment ground. I'm not an idiot i just made a stupid mistake! Thank you for your responses.

 

[anothaparson]

If memory serves, 10/2 was never legal.

I've seen a lot of 3 prong clothes dryer receptacles. 240V with an equipment ground, I guess my inexperience led me to believe I had a choice between a 3 wire and a 2 wire.

 

[ceb58]

If memory serves, 10/2 was never legal.

I would say it was once apon a time due to what the exception to 250.140 says

Exception: For existing branch-circuit installations onlywhere an equipment grounding conductor is not present inthe outlet or junction box, the frames of electric ranges,wall-mounted ovens, counter-mounted cooking units,clothes dryers, and outlet or junction boxes that are part ofthe circuit for these appliances shall be permitted to beconnected to the grounded circuit conductor if all the followingconditions are met.(1) The supply circuit is 120/240-volt, single-phase, 3-wire;or 208Y/120-volt derived from a 3-phase, 4-wire, wyeconnectedsystem.(2) The grounded conductor is not smaller than 10 AWGcopper or 8 AWG aluminum.(3) The grounded conductor is insulated, or the groundedconductor is uninsulated and part of a Type SE serviceentrancecable and the branch circuit originates at theservice equipment.(4) Grounding contacts of receptacles furnished as part of​

the equipment are bonded to the equipment.

look at excpt. 3 I have ran into many that were the old SE 2wire with bare ground on stoves and dryers

 

[anothaparson]

Simple answer, on a new standard dryer installation you need 10/3.

Is there a code reference to this or is this how the manufacturers are building them?

 

[anothaparson]

I would say it was once apon a time due to what the exception to 250.140 says
look at excpt. 3 I have ran into many that were the old SE 2wire with bare ground on stoves and dryers

I also read that before my initial post, which led me to posting a question to inquire of what NEC was asking us to do? Didn't have much luck finding it in my NEC book.

 

[infinity]

Simple answer, on a new standard dryer installation you need 10/3.

Is there a code reference to this or is this how the manufacturers are building them?

Yes there is. I don't have it in front of me but someone will post it I'm sure. :happyyes:

 

[ceb58]

I also read that before my initial post, which led me to posting a question to inquire of what NEC was asking us to do? Didn't have much luck finding it in my NEC book.

250.140 tells you every thing you need to know. If it is a new install you must have an EGC with the wiring. But the exception tells you that if it is an existing install and it was 2/w a ground then it could be used. Reason being if some one bought a new stove,dryer they would have to have the branch circuit replaced and that's not going to happen.

 

[anothaparson]

Yes there is. I don't have it in front of me but someone will post it I'm sure. :happyyes:

I appreciate you not ridicule me. I think that i should have asked the question 2 days ago before i purchased the material. They didn't have a dryer in place to cross-reference from, only that they wanted a circuit for it. I just want to do what's right and I'll accept the redicule, because I know better than to make this dumb mistake. Thanks Bob

 

[anothaparson]

I appreciate you not ridicule me. I think that i should have asked the question 2 days ago before i purchased the material. They didn't have a dryer in place to cross-reference from, only that they wanted a circuit for it. I just want to do what's right and I'll accept the redicule, because I know better than to make this dumb mistake. Thanks Bob

Sorry Thank you Rob.

 

[anothaparson]

250.140 tells you every thing you need to know. If it is a new install you must have an EGC with the wiring. But the exception tells you that if it is an existing install and it was 2/w a ground then it could be used. Reason being if some one bought a new stove,dryer they would have to have the branch circuit replaced and that's not going to happen.

Code section 250.140 Exception 1.

 

[Sierrasparky]

There are 240v only Electric dryers.
So you did not make an entire mistake..

 

[anothaparson]

Most electric dryers have 240 v heating elements, 120 volt control panel and 120 volt motor that turns the drum.
If this is what you have, then you would need 3 # 10 cu + egc. You need to check to see if MC is allowed to be used as the egc.
Does this answer your question? The MFG should have information regarding the requirements.
I was late posting behind templdl and gus.

Code section 250.118 Types of Equipment Grounding Conductors list MC as #10 on the list along with EMT, Rigid, Flexible metallic, etc... Just as an informational topic because I did run MC and all conductors are insulated in theory would I be code compliant if the equipment grounding conductor was re-identified with white tape and used as the nuetral conductor? This is merely a hypothetical question and i'm not going to embarass myself any further by asking AHJ if this will fly.

 

[anothaparson]

Code section 250.118 Types of Equipment Grounding Conductors list MC as #10 on the list along with EMT, Rigid, Flexible metallic, etc... Just as an informational topic because I did run MC and all conductors are insulated in theory would I be code compliant if the equipment grounding conductor was re-identified with white tape and used as the nuetral conductor? This is merely a hypothetical question and i'm not going to embarass myself any further by asking AHJ if this will fly.

...in addition to 250.118 does code section 250.134 Equipment Fastened in Place or connected by Permanent Wiring Methods (Fixed) - Grounding pertain to this situation?