2 wire range circuit

[journeyman0217]

hi all,
i came across a 2 wire range circuit in a kitchen reno. When renovating, "by code" should this wire be upgraded to 3 wire (2 hots, neutral, ground). I can't seem to find anything in article 422 or article 210 saying that it has to be changed to 3 wire. thanks in advance!

 

[journeyman0217]

i found in article 250.140 exception 3 states an "existing" 2 wire circuit can be connected to frame of range. still wondering if because the kicthen is being renovated does the wire need to be re-run...:?

 

[user 100]

hi all,
i came across a 2 wire range circuit in a kitchen reno. When renovating, "by code" should this wire be upgraded to 3 wire (2 hots, neutral, ground). I can't seem to find anything in article 422 or article 210 saying that it has to be changed to 3 wire. thanks in advance!

i found in article 250.140 exception 3 states an "existing" 2 wire circuit can be connected to frame of range. still wondering if because the kicthen is being renovated does the wire need to be re-run...:?

Depends on what you mean by renovating.

As long as the existing ckt isn't altered (i.e.-extended), its still NEC legal.

 

[goldstar]

Make sure you read this part of the exception

shall be permitted to be connected to the grounded circuit conductor if ALL the following conditions are met.

IMHO, if it's a short and easy replacement and you don't have to break open any walls I would make the change just to keep things up to the latest Code.

 

[journeyman0217]

Where would i find in the code where it states that if its altered that it would have to be re-run? I personally would re-run it myself but its for a General contractor and he doesnt want to pay for replacement if it is not needed per code. thats what im up against...

 

[jumper]

Where would i find in the code where it states that if its altered that it would have to be re-run? I personally would re-run it myself but its for a General contractor and he doesnt want to pay for replacement if it is not needed per code. thats what im up against...

If you mean what code mandates when you have to replace, that would a building/administration code for your jurisdiction for remodel/renovation rules.

The NEC just addresses new and existing untouched installations.

 

[MAC702]

Are any of these existing 3-wire circuits considered to actually be dangerous, even though the 4-wire is the current way to do it? If not, I wouldn't be trying to replace it unless I was required to do so.

 

[jumper]

Are any of these existing 3-wire circuits considered to actually be dangerous, even though the 4-wire is the current way to do it?

I will only say that there have been more than a few statements here that there there was little empirical evidence that the the three wire circuits to dryers and ranges were a safety concern that caused the rule to be changed in 1996.

It seems more that it was a matter of just making these circuits more in line with other branch circuit requirements.

The fact that code specifically allows existing to stay rather implies this train of thought IMO.

I am not agreeing or disagreeing, just repeating what I have read.

 

[MAC702]

...It seems more that it was a matter of just making these circuits more in line with other branch circuit requirements.

The fact that code specifically allows existing to stay rather implies this train of thought IMO...

This has always been my assumption, so I was hoping there wasn't some big news I'd not heard about. Thanks.

 

[JFletcher]

Are any of these existing 3-wire circuits considered to actually be dangerous, even though the 4-wire is the current way to do it? If not, I wouldn't be trying to replace it unless I was required to do so.

Not if installed properly 25+ years ago.

The way the AHJs here interpret 250.140 is on the word "existing". If the circuit is untouched, then it is existing and can stay. Move it anywhere, even closer to the panel, it's no longer "existing" and has to go to 4 wire.

99% of kitchen remodels are going to move the stove/range and you'll be running new wire anyway.

 

[jumper]

Not if installed properly 25+ years ago.

The way the AHJs here interpret 250.140 is on the word "existing". If the circuit is untouched, then it is existing and can stay. Move it anywhere, even closer to the panel, it's no longer "existing" and has to go to 4 wire.

99% of kitchen remodels are going to move the stove/range and you'll be running new wire anyway.

Not in your area or Richmond, but where I used to be, Farmville or Prince Edward County, inspectors were a bit more lenient and would overlook moving it a small amount as long as no splicing and extending was involved.

 

[journeyman0217]

agreed... thanks!

 

[david]

I will only say that there have been more than a few statements here that there there was little empirical evidence that the the three wire circuits to dryers and ranges were a safety concern that caused the rule to be changed in 1996.

It seems more that it was a matter of just making these circuits more in line with other branch circuit requirements.

The fact that code specifically allows existing to stay rather implies this train of thought IMO.

I am not agreeing or disagreeing, just repeating what I have read.

Actually I seen a stove top where a short piece of flexible metal conduit became hot because of a three wire circuit.

The flex went from a metal junction box where the neutral/ equipment ground was bonded at a jbox flex to the stove top.

The connector for the flex was lose and paralleled neutral current. The lose connection turned black from the heat. when you looked under the cabinet with the lights out and the cook top being used you could see the heat at the connector.

 

[jumper]

Actually I seen a stove top where a short piece of flexible metal conduit became hot because of a three wire circuit.

The flex did not become energized because of the 3 wire circuit, it happened as a result of poor workmanship.

An improperly installed 4 wire circuit is just as dangerous.

Think of all the cases where there is a 4 wire run, but the N/G strap inside the appliance wiring compartment is never removed.

 

[david]

the point wasn't the poor maintenance of the circuit. rather the metal flex would not become a current carrying circuit conductor in a four wire system. In a four wire system had the neutral circuit conductor splice been compromised it would have effected the appliance and would not have gone unnoticed. heating was no more than an inch from the wooded cabinet (plywood).

The high temp leads from the cook top to the jay box allowed the circuit conductors to not short out by insulation damage.

This condition would be way less likely in a four wire circuit

 

[david]

The flex did not become energized because of the 3 wire circuit, it happened as a result of poor workmanship.

An improperly installed 4 wire circuit is just as dangerous.

Think of all the cases where there is a 4 wire run, but the N/G strap inside the appliance wiring compartment is never removed.

and why was the flex not a current carrying conductor under good maintenance conditions.

the flex was current carrying under normal conditions. the poor maintenance resulted in a loose connection and to over heat.

 

[kwired]

the point wasn't the poor maintenance of the circuit. rather the metal flex would not become a current carrying circuit conductor in a four wire system. In a four wire system had the neutral circuit conductor splice been compromised it would have effected the appliance and would not have gone unnoticed. heating was no more than an inch from the wooded cabinet (plywood).

The high temp leads from the cook top to the jay box allowed the circuit conductors to not short out by insulation damage.

This condition would be way less likely in a four wire circuit

Many units only have neutral load that is just controls - an oven light might be highest neutral load involved most cases. If the neutral is otherwise solid- loose flex fitting will not carry much if any current as the parallel neutral will carry bulk of the load if that loose connector has some resistance

 

[david]

Many units only have neutral load that is just controls - an oven light might be highest neutral load involved most cases. If the neutral is otherwise solid- loose flex fitting will not carry much if any current as the parallel neutral will carry bulk of the load if that loose connector has some resistance

i can only say what i saw, i did not trouble shoot the circuit it was at a relative who had electrical back ground.

after the flex connector was changed the issue went away

the cook top was an older appliance maybe 18 years old

as an after thought he would have had to re-due the splices in the jbox for the circuit maybe that as well had something to do with resolving an issue, cant say

 

[jumper]

David,

Your single isolated experience does not mean that the thousands of existing installs are unsafe.

A lone “what if” scenario IMO.

There are way more cases where that does not happen.

Operator error, flex should not have loose.

 

[user 100]

and why was the flex not a current carrying conductor under good maintenance conditions.

the flex was current carrying under normal conditions. the poor maintenance resulted in a loose connection and to over heat.

Many units only have neutral load that is just controls - an oven light might be highest neutral load involved most cases. If the neutral is otherwise solid- loose flex fitting will not carry much if any current as the parallel neutral will carry bulk of the load if that loose connector has some resistance

^^^^
This

No problem with the 3w installation as long as the noodle isn't compromised.

An improperly installed 4 wire circuit is just as dangerous.

Think of all the cases where there is a 4 wire run, but the N/G strap inside the appliance wiring compartment is never removed.

:thumbsup:

And unfortunately way too common among app installers and HO's.