NEC 250.140 and 142

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resistance

Senior Member
Location
WA
Ok, I have a question. Based on Section 250.140, and .142.

Hypo: A 3 conductor SE cable serving an existing electric wall oven needs to be moved. Based on the NEC sections posted. Can the existing SE cable be extended to serve a new wall mounted oven--located in a new location?
 

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
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Ok, I have a question. Based on Section 250.140, and .142.

Hypo: A 3 conductor SE cable serving an existing electric wall oven needs to be moved. Based on the NEC sections posted. Can the existing SE cable be extended to serve a new wall mounted oven--located in a new location?

I would say no.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
and why not? show me in the code where it says no. dont just guess.
To me, 250.140 says so. The rule says grounding by an equipment ground, the exception applies to EXISTING circuits. When you install any new wiring on a circuit, IMHO, it no longer is consider existing.
 

sparkyboys

Senior Member
Location
Columbus, ga
well 250.140 and 142 do not specify on TAPS. I am looking at the book now 2008. why dont you look up feeder taps in 240.92b and then refer to 240.21b2 any oven rated not over 8 3/4 kw. because it says differently than what you say.
 

radiopet

Senior Member
Location
Spotsylvania, VA
Firstly, debate is one thing but accusing people of guessing versus posting what they believe is right is a different story. I do not find that Bob or Dennis guess very much as most of their posts are based on the NEC and how it reads.

I personally ( maybe it is just me ) do not see where your examples of 240.92(B) or 240.21(B)(2) applies to any of the OP's question. We are not talking about taps in regards to the overcurrent protection at the tap location and so on that those reference you gave apply to. We are talking about the extending of an existing circuit.

250.140 Frames of Ranges and Clothes Dryers. 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
connected to the equipment grounding conductor in the
manner specified by 250.134 or 250.138.

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, wye-connected 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.

If the ovens are being moved to a new location then it is not existing anymore and thats not guessing anymore than you are guessing that 240.21(B)(2) applies which is for tap rules on overcurrent protection afforded at the tap. In the end it will be up to the local AHJ to determine in their own mind what constitutes an existing branch circuit versus the line when it is no longer considered existing, in the end everyone is guessing based on what they consider existing and where they draw the line.

Point is, no one is guessing. They are posting on what they believe is right as you are also and I dont see anyone saying YOU are guessing?... I post here all the time certain things JUST to hear others chime in with their opinion and sometimes I agree and sometimes I dont.....it's all good but I would not say we are all guessing when it is what we believe is correct.
 

don_resqcapt19

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Location
Illinois
Occupation
retired electrician
250.140 and 142 are not specifying existing or taps. you are just guessing
No guesses here. If you add wire, it is not existing...it is new. The exception is to permit the replacement of the appliance without requiring the installation of a new circuit. You may, as Bob said, get the inspector to permit the exception, but there is no code reason he has to permit you to extend the circuit.
The rule in 240.92(B) only applies to Supervised Industrial Installations. The rule in 240.21(B) has nothing to do with the question of new or existing which in the only thing that needs to be answered.
 

roger

Moderator
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Location
Fl
Occupation
Retired Electrician
well 250.140 and 142 do not specify on TAPS.
Help me out here, how does this circuit extension become a tap?
I am looking at the book now 2008. why dont you look up feeder taps in 240.92b
Go back to article 100 and see the definition of "Feeder"
and then refer to 240.21b2 any oven rated not over 8 3/4 kw. because it says differently than what you say.
The issue at hand is whether extending this circuit allows the user to still utilize the grounded conductor as an EGC, not OCP for a circuit or tap.

Tapping a circuit be it a feeder or a branch circuit does not negate Art 250 bonding requirements.

Roger
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Ok, I have a question. Based on Section 250.140, and .142.

Hypo: A 3 conductor SE cable serving an existing electric wall oven needs to be moved. Based on the NEC sections posted. Can the existing SE cable be extended to serve a new wall mounted oven--located in a new location?

the wire is already existing, the oven-existing, just being moved

possibly.....when I read "extended" I assume some new wiring, thus, to me, not an existing situation.
As far as 240.21(b)(2)(b), I would need your help showing me where that is applicable.
 

sparkyboys

Senior Member
Location
Columbus, ga
(Can the existing SE cable be extended to serve a new wall mounted oven)
scenario:

If a homeowner, who new of electrical work and wanted to install a new oven under the 8 3/4kw limit and the length of the wire under or at the maximum length of 25ft, could that person use a junction box and wire nuts to a new spot using 240.21b2?
 

iwire

Moderator
Staff member
Location
Massachusetts
If a homeowner, who new of electrical work and wanted to install a new oven under the 8 3/4kw limit and the length of the wire under or at the maximum length of 25ft, could that person use a junction box and wire nuts to a new spot using 240.21b2?

OK I will try to answer your question without guessing. :smile:

The conductors running to oven, range or stove top are not feeders they are branch circuit conductors. (See definitions of feeder and branch circuit in Article 100) The fact that these conductors are not feeders means that none of 240.21(B) applies as those sections apply only to feeders. (See 240.21(B) Feeder Taps)

Also even if 240.21(B)(2) could be used for branch circuits (and it can not be) 240.21(B)(2)(2) requires the tap conductors to terminate in a circuit breaker not utilization equipment.

Now that 240.21(B) is behind us we might be able to use 210.19(A)(3) Exception 1. That exception allows tapping a 50 amp circuit with a minimum of 20 amp conductors that have an ampacity of at least the load to be served. ut it also requires the conductors be as short as possible.

But IMO 210.19(A)(3) Exception 1 is not intended for extending a circuit but it is intended to allow suppling a wall mount oven and counter top stove unit mounted near each other to be served with one 50 amp branch circuit.


HOWEVER, none of the above is on topic, the original poster is asking about a situation where the existing circuit has two hots and Neutral (3 wire stove receptacle) that was also used as the grounding means for the range. He is asking if he can now extend that old 3 wire branch circuit to a new location by using 250.140 exception. The answer to that is no. The new wiring needs to be four wire, two hots, a neutral and a ground. The NEC no longer allows using the neutral as the grounding means for the frames of ranges or clothes dryers.

Now I took the time not to guess and have provided the code references, please take the time to look at the code sections and definitions I listed before responding back. :smile:
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Sparky, it is many of our opinions that once a range is moved it is not an existing situation. As Bob pointed out you can ask the ahj to help you on this one but in many areas this would be considered a new installation.

Some inspectors in our area will allow the existing wire if it is not possible, without removal of walls, to add a new circuit.
 
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