Range and Clothes Dryer Wiring

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czars

Czars
Location
West Melbourne, FL
Occupation
Florida Certified Electrical Contractor
I've had a couple of instances lately that involved existing branch circuit wiring for ranges and clothes dryers in condos. In both instances the equipment was supplied from the service panels in the condos which were not service equipment. The wiring for the ranges and dryers was NM cable with two insulated conductors and and uninsulated EGC. The wiring in both cases was inaccessible.

In the case of the dryer, the 3 slot receptacle was worn out and had to be replaced. In the case of the range, a new range was procured and had to be hooked-up via a 3 slot receptacle. In both cases I connected the frames to the EGC and for the range, connected the range neutral to the EGC also.

The requirements for existing installations spelled out in NEC 250.140 clearly were not met. Did I really screw up by not insisting that the branch circuit wiring be replaced or was what I did OK?
 
czars said:
I've had a couple of instances lately that involved existing branch circuit wiring for ranges and clothes dryers in condos. In both instances the equipment was supplied from the service panels in the condos which were not service equipment. The wiring for the ranges and dryers was NM cable with two insulated conductors and and uninsulated EGC. The wiring in both cases was inaccessible.

In the case of the dryer, the 3 slot receptacle was worn out and had to be replaced. In the case of the range, a new range was procured and had to be hooked-up via a 3 slot receptacle. In both cases I connected the frames to the EGC and for the range, connected the range neutral to the EGC also.

The requirements for existing installations spelled out in NEC 250.140 clearly were not met. Did I really screw up by not insisting that the branch circuit wiring be replaced or was what I did OK?
Click to expand...

Like you said, its a code violation and you got current flowing on that non insulated ground. Hopefully the outer sheath will keep any potential issues from happening. If you can correct this you should.
 
czars said:
I've had a couple of instances lately that involved existing branch circuit wiring for ranges and clothes dryers in condos. In both instances the equipment was supplied from the service panels in the condos which were not service equipment. The wiring for the ranges and dryers was NM cable with two insulated conductors and and uninsulated EGC. The wiring in both cases was inaccessible.

In the case of the dryer, the 3 slot receptacle was worn out and had to be replaced. In the case of the range, a new range was procured and had to be hooked-up via a 3 slot receptacle. In both cases I connected the frames to the EGC and for the range, connected the range neutral to the EGC also.

The requirements for existing installations spelled out in NEC 250.140 clearly were not met. Did I really screw up by not insisting that the branch circuit wiring be replaced or was what I did OK?
Click to expand...

250.140 Exception allows for this existing installation to remain and be code compliant. IMO you were OK with leaving the existing 3 wire and using the grounded conductor to bond the frames is allowed for existing installations were an equipment grounding conductor does not exist.
 
Riograndeelectric said:
250.140 Exception allows for this existing installation to remain and be code compliant. IMO you were OK with leaving the existing 3 wire and using the grounded conductor to bond the frames is allowed for existing installations were an equipment grounding conductor does not exist.
Click to expand...

He said he connected the 'range neutral' to the egc not the neutral from the branch circuit. Unless I'm missing something here concerning the feed, he is not compliant and do not meet 250.140
 
brother said:
He said he connected the 'range neutral' to the egc not the neutral from the branch circuit. Unless I'm missing something here concerning the feed, he is not compliant and do not meet 250.140
Click to expand...


pardon me . I miss read the OP.

I would classify the bare conductors as Neutral/ grounded conductor and not as an EGC. just my opinion


if you could consider the bare conductor then the Exception would be allowed
 
Riograndeelectric said:
pardon me . I miss read the OP.

I would classify the bare conductors as Neutral/ grounded conductor and not as an EGC. just my opinion


if you could consider the bare conductor then the Exception would be allowed
Click to expand...

the op stated that it was NM cable how would the bare conductor in NM cable ( not SE Cable) be allowed for Nuetral current?
 
Riograndeelectric said:
pardon me . I miss read the OP.

I would classify the bare conductors as Neutral/ grounded conductor and not as an EGC. just my opinion


if you could consider the bare conductor then the Exception would be allowed
Click to expand...

I think the OP was referring to a main lug panel in the condo where this branch circuit is coming from and that that is not service equipment. There is a note in the code handbook (2005) that seems to indicate that. I had the same situation in an apartment building I do work in, all the ranges are wired from the apartment panels (sub-panels, no main) in type SE cable, bare neutral. The note said "...the branch circuit was required to originate at the service equipment to avoid neutral current from downstream panelboards...) Don't know if I'm understanding this correctly and if it was compliant at one time.
 
At least at a sub-panel you can tell whether it is a neutral or an EGC by which bus it lands on.
If the new range generates neutral current, then the conductor must terminate on the neutral bar. Of course, at the service panel it wouldn't be distinguishable.

Sent from my XT1080 using Tapatalk
 
The exception always required the bare conductor for SE cable to originate at the service if the bare conductor was used for a current carring conductor. You where never allowed to use a bare conductor for a range or dryer as a current carring conductor for sub-panels.
 
From my 1999

338.3b.JPG

250.140
Exception: For existing branch-circuit installations only
where an equipment grounding conductor is not present in
the 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 of
the circuit for these appliances shall be permitted to be
connected to the grounded circuit conductor if all the following
conditions 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, wyeconnected
system.
(2) The grounded conductor is not smaller than 10 AWG
copper or 8 AWG aluminum.
(3) The grounded conductor is insulated, or the grounded
conductor is uninsulated and part of a Type SE serviceentrance
cable and the branch circuit originates at the
service equipment.
(4) Grounding contacts of receptacles furnished as part of
the equipment are bonded to the equipment.


Service Equipment. The necessary equipment, usually consisting
of a circuit breaker(s) or switch(es) and fuse(s) and
their accessories, connected to the load end of service conductors
to a building or other structure, or an otherwise designated
area, and intended to constitute the main control and cutoff of
the supply.

If the original electrical inspector considered the so called "sub panel" to be service equipment I would say that you are code compliant. You are connected to the 'neutral' bar. Correct?

90.4
By special permission, the authority having jurisdiction
may waive specific requirements in this Code or permit
alternative methods where it is assured that equivalent objectives
can be achieved by establishing and maintaining
effective safety.
 
jxofaltrds said:
From my 1999

View attachment 9521

250.140
Exception: For existing branch-circuit installations only
where an equipment grounding conductor is not present in
the 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 of
the circuit for these appliances shall be permitted to be
connected to the grounded circuit conductor if all the following
conditions 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, wyeconnected
system.
(2) The grounded conductor is not smaller than 10 AWG
copper or 8 AWG aluminum.
(3) The grounded conductor is insulated, or the grounded
conductor is uninsulated and part of a Type SE serviceentrance
cable and the branch circuit originates at the
service equipment.
(4) Grounding contacts of receptacles furnished as part of
the equipment are bonded to the equipment.


Service Equipment. The necessary equipment, usually consisting
of a circuit breaker(s) or switch(es) and fuse(s) and
their accessories, connected to the load end of service conductors
to a building or other structure, or an otherwise designated
area, and intended to constitute the main control and cutoff of
the supply.

If the original electrical inspector considered the so called "sub panel" to be service equipment I would say that you are code compliant. You are connected to the 'neutral' bar. Correct?

90.4
By special permission, the authority having jurisdiction
may waive specific requirements in this Code or permit
alternative methods where it is assured that equivalent objectives
can be achieved by establishing and maintaining
effective safety.
Click to expand...

I think that clears up my question. The apartment complex I'm talking about is four separate two story brick buildings with about 20 units each and each one has mains in the basement and sub panels in the apartments with SE cable bare neutral run to the ranges. Must of been Ok at some point.
 
brother said:
He said he connected the 'range neutral' to the egc not the neutral from the branch circuit. Unless I'm missing something here concerning the feed, he is not compliant and do not meet 250.140
Click to expand...

After rre reading the OP I missed the part about the wiring method being NM cable.
I had assumed it was type SEU cable.
So in fact the NM EGC can not be used as the Grounded conductor.
 
Riograndeelectric said:
250.140 Exception allows for this existing installation to remain and be code compliant. IMO you were OK with leaving the existing 3 wire and using the grounded conductor to bond the frames is allowed for existing installations were an equipment grounding conductor does not exist.
Click to expand...

Riograndeelectric said:
pardon me . I miss read the OP.

I would classify the bare conductors as Neutral/ grounded conductor and not as an EGC. just my opinion


if you could consider the bare conductor then the Exception would be allowed
Click to expand...

Riograndeelectric said:
After rre reading the OP I missed the part about the wiring method being NM cable.
I had assumed it was type SEU cable.
So in fact the NM EGC can not be used as the Grounded conductor.
Click to expand...

In this thread I understand the op as stating that the ranges are supplied from the sub-panels in the apartments. The NEC would have required a(240/120 volt) supply to the sub-panels with four wire feeds. It would not matter if the cable was NM or SE the exception was not applicable to ranges and dryers being supplied past the service equipment.
 
jxofaltrds said:
From my 1999

View attachment 9521


If the original electrical inspector considered the so called "sub panel" to be service equipment I would say that you are code compliant. You are connected to the 'neutral' bar. Correct?
Click to expand...

GerryB said:
I think that clears up my question. The apartment complex I'm talking about is four separate two story brick buildings with about 20 units each and each one has mains in the basement and sub panels in the apartments with SE cable bare neutral run to the ranges. Must of been Ok at some point.
Click to expand...

There is no way that the sub-panels in these apartments could be defined as service equipment.
The Op states that the serviced equipment originates in the basement.
The installation may have been approved by an electrical inspector in the past, or the installation may never had been inspected. The installation as described by the OP is not in compliance with the NEC.
 
david said:
In this thread I understand the op as stating that the ranges are supplied from the sub-panels in the apartments. The NEC would have required a(240/120 volt) supply to the sub-panels with four wire feeds. It would not matter if the cable was NM or SE the exception was not applicable to ranges and dryers being supplied past the service equipment.
Click to expand...

What if nothing was codified (or something other than the NEC) when this was built? If it was approved before, that makes it code compliant (at that time).

I believe that the SE exception could be used for reasons that I stated above.
 
jxofaltrds said:
What if nothing was codified (or something other than the NEC) when this was built? If it was approved before, that makes it code compliant (at that time).

I believe that the SE exception could be used for reasons that I stated above.
Click to expand...

Without the NEC being the point of reference I am not sure how to have a discussion on installation being compliant with the Code. (NEC)
 
czars said:
I've had a couple of instances lately that involved existing branch circuit wiring for ranges and clothes dryers in condos. In both instances the equipment was supplied from the service panels in the condos which were not service equipment. The wiring for the ranges and dryers was NM cable with two insulated conductors and and uninsulated EGC. The wiring in both cases was inaccessible.

In the case of the dryer, the 3 slot receptacle was worn out and had to be replaced. In the case of the range, a new range was procured and had to be hooked-up via a 3 slot receptacle. In both cases I connected the frames to the EGC and for the range, connected the range neutral to the EGC also.

The requirements for existing installations spelled out in NEC 250.140 clearly were not met. Did I really screw up by not insisting that the branch circuit wiring be replaced or was what I did OK?
Click to expand...

I also missed the fact that it was NM cable. At least in my case, (the apt building with sub panels and SE cable to the ranges) I could say I didn't realize the sub panels were not service equipment, which I didn't until this post if I'm getting it right. But if someone ran 10-2 romex to the dryer and 8 or 6-2 to the range they didn't know what they were doing and maybe you should have tried to get out of it.
 
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