2 wire range circuit

[jumper]

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

Yes and applies to umpteen millions of services besides ranges and dryers.

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

But we certainly would not want more codes written because of a few actions of unqualified people.

It happens all too often already.

 

[sameguy]

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!

This is why having good inspector relationships can make you money, I have called my different inspectors and had my ducks in a row so not wasting their time; they learned I could think and we all were happy. To the point I never needed to be on site with them, but tried to be, and could get inspections on jobs "early " under my masters or when I worked under an other master. The body having jurisdiction!

 

[Jraef]

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!

Regardless of being FORCED by code to upgrade, I think it's the right thing to do. When that was installed, it was likely that a range was "just a range"; meaning mechanical control knobs, no vent fans etc. Anything modern will have controls and likely lights or maybe downdraft fans, so will require a Neutral to get 120V for them. With no neutral available, the HO or appliance store installer will likely connect to the ground to get it to function and that sets up an unsafe situation. I would opt for doing it right...

 

[david]

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.

i could agree with that, but if the discussion was leaning toward there is no difference in safety between a three wire circuit and a four wire circuit we may have to disagree.

i been shocked to many times on the the metal siding on manufactured homes when the four wire sytsem is compromised, and that two is from personal experience. Thank goodness that manufactures have gotten away from metal siding on these homes

 

[MAC702]

Regardless of being FORCED by code to upgrade, I think it's the right thing to do. When that was installed, it was likely that a range was "just a range"; meaning mechanical control knobs, no vent fans etc. Anything modern will have controls and likely lights or maybe downdraft fans, so will require a Neutral to get 120V for them. With no neutral available, the HO or appliance store installer will likely connect to the ground to get it to function and that sets up an unsafe situation. I would opt for doing it right...

3-wire circuits HAVE a neutral. It's bonded to the frame to be used as the EGC also.
This is not an EGC being used as a neutral.

There may be some confusion in the thread title, as we seem to be discussing the common 3- v 4-wire circuits, not a 2- v 3-wire issue.

 

[jumper]

Regardless of being FORCED by code to upgrade, I think it's the right thing to do. When that was installed, it was likely that a range was "just a range"; meaning mechanical control knobs, no vent fans etc. Anything modern will have controls and likely lights or maybe downdraft fans, so will require a Neutral to get 120V for them. With no neutral available, the HO or appliance store installer will likely connect to the ground to get it to function and that sets up an unsafe situation. I would opt for doing it right...

Actually if the original wire was correct, it would have a neutral and no EGC.

SE cable is okay, but not NM.

The neutral was used for bonding instead of using an EGC for unbalanced current.

Edit: Sorry Mac, did not see your post.

 

[jumper]

i could agree with that, but if the discussion was leaning toward there is no difference in safety between a three wire circuit and a four wire circuit we may have to disagree.

Lemme rephrase my position a little:

Yes, for branch circuits that require a neutral a 4 wire circuit with an EGC is safer than a 3 wire one.

However, this does not mean that existing 3 wire installs to ranges and dryers are inherently unsafe.

 

[Jraef]

3-wire circuits HAVE a neutral. It's bonded to the frame to be used as the EGC also.
This is not an EGC being used as a neutral.

There may be some confusion in the thread title, as we seem to be discussing the common 3- v 4-wire circuits, not a 2- v 3-wire issue.

Right. That's why I had quoted the original post, where he said "2 wire" and asked if he SHOULD go to 3 wire. I assumed 2 wire is 2 hot wires w/g and bonded internally or not, there is no legal 120V circuit in that. So my point was that if he does NOT change it to 3W w/g, someone may end up using the ground connection to get the 120V, and that would become a problem.

 

[jumper]

Right. That's why I had quoted the original post, where he said "2 wire" and asked if he SHOULD go to 3 wire. I assumed 2 wire is 2 hot wires w/g and bonded internally or not, there is no legal 120V circuit in that. So my point was that if he does NOT change it to 3W w/g, someone may end up using the ground connection to get the 120V, and that would become a problem.

Again, it should be a piece of SE cable to be legal, 2 hots and a noodle, so it would be okay to have a 120V circuit here.

Edit: Okay, I see your point. My guess though is that OP just screwed up his description.

 

[MAC702]

Right. That's why I had quoted the original post, where he said "2 wire" and asked if he SHOULD go to 3 wire. I assumed 2 wire is 2 hot wires w/g and bonded internally or not, there is no legal 120V circuit in that. So my point was that if he does NOT change it to 3W w/g, someone may end up using the ground connection to get the 120V, and that would become a problem.

Agreed.

 

[drcampbell]

... the cook top was an older appliance maybe 18 years old ...

I doubt this applies to a c.2000 appliance but wasn't it common for much older stoves to switch between 240v (L-L) and 120v (L-N) to control the surface elements' heat rate? That would impose a substantial current on the "neutral" wire.

It's a little ironic that we'll probably end up converting to 4-wire stove receptacles about the same time stoves convert to wide-voltage-tolerance switch-mode power supplies and stop using the "neutral" wire.

On a related note, I always wondered why electric dryers didn't use a 240-volt motor. Does anybody know the rationale behind that? There were certainly enough of them manufactured that using a common part for both gas & electric dryers wouldn't have been compelling.

 

[MAC702]

...It's a little ironic that we'll probably end up converting to 4-wire stove receptacles about the same time stoves convert to wide-voltage-tolerance switch-mode power supplies and stop using the "neutral" wire.

On a related note, I always wondered why electric dryers didn't use a 240-volt motor. Does anybody know the rationale behind that? There were certainly enough of them manufactured that using a common part for both gas & electric dryers wouldn't have been compelling.

You're not crazy. Unless I am, too. I Have always wondered why we are not just using 240V motors and controls. I've never seen a need for a neutral to have ever been designed into these.

The first one used some common 120V parts and screwed it for everyone.

 

[jumper]

On a related note, I always wondered why electric dryers didn't use a 240-volt motor. Does anybody know the rationale behind that? There were certainly enough of them manufactured that using a common part for both gas & electric dryers wouldn't have been compelling.

You're not crazy. Unless I am, too. I Have always wondered why we are not just using 240V motors and controls. I've never seen a need for a neutral to have ever been designed into these.

The first one used some common 120V parts and screwed it for everyone.

Thanks guys, now I am curious too.:rant:

I will end up wasting a couple hours trying to find the darn reason....

Why? Because I is a geek. ?

 

[norcal]

I doubt this applies to a c.2000 appliance but wasn't it common for much older stoves to switch between 240v (L-L) and 120v (L-N) to control the surface elements' heat rate? That would impose a substantial current on the "neutral" wire.

It's a little ironic that we'll probably end up converting to 4-wire stove receptacles about the same time stoves convert to wide-voltage-tolerance switch-mode power supplies and stop using the "neutral" wire.

On a related note, I always wondered why electric dryers didn't use a 240-volt motor. Does anybody know the rationale behind that? There were certainly enough of them manufactured that using a common part for both gas & electric dryers wouldn't have been compelling.

Gas dryers normally only require 120V, making them a 240V commodity would not be a very good idea. The reasoning for using a 120V motor & controls in electric dryers would be interesting to know.

Adding all the electronics seems to be the reason newer appliances are garbage at best, 5 year life span is what am hearing which makes them a huge waste of natural resources.

 

[jumper]

Well so far I have found an abundance of conflicting opinions, outrageous bull, common hearsay, general ignorance, and overall worthless info......

My favorite: “Too much 240V voltage on the circuit would blow the fuses.”:blink:

If I get real ambitious I might fire a few emails to a manufacturer or two and maybe get a reasonable answer.

 

[kwired]

Well so far I have found an abundance of conflicting opinions, outrageous bull, common hearsay, general ignorance, and overall worthless info......

My favorite: “Too much 240V voltage on the circuit would blow the fuses.”:blink:

If I get real ambitious I might fire a few emails to a manufacturer or two and maybe get a reasonable answer.

Don't hold your breath while waiting.

First you would need to contact someone involved in the designing of them otherwise the customer service type representatives only know how to look into information databases to come up with an answer that may or may not be correct.

Second, I can almost tell you the main driving factor is to keep cost down. If it is a high end machine that might not be much factor, but most the common machines will consider every penny involved to remain competitive on the market.

If you try to buy parts for newer machines you often find out that your part fits more then one brand these days - the separate names are still there, but some must all be under one company now.

 

[ActionDave]

It has always been about the gas dryer. The same motor and controls work for gas dryers and electric dryers, so it's more cost effective to use them in both types of dryers.

 

[jumper]

It has always been about the gas dryer. The same motor and controls work for gas dryers and electric dryers, so it's more cost effective to use them in both types of dryers.

More than of a few of the credible sources I found posed this as the reason.

Seems to make the most sense so far.

 

[growler]

If you try to buy parts for newer machines you often find out that your part fits more then one brand these days - the separate names are still there, but some must all be under one company now.

Back in the early 90s I was looking for a transmission for a mid 80s model Ford Mustage. I was really surprised to see just how many cars that had used that very same transmission over the years.

Why wouldn't the same part be used for a number of machines? It cost a lot to develope a new product/part and there is no reason to do so if there is a perfectly good part out there for sale at a reasonable price.

 

[drcampbell]

... The same motor and controls work for gas dryers and electric dryers, so it's more cost effective to use them in both types of dryers.

That's true only until you're manufacturing so many of them that you need to set up multiple production lines to meet the demand. Once you need more than one production line, the economy of commonality no longer applies, and I would assume that it would be cheaper to make a dryer that doesn't use a "neutral" wire or the associated connections. Wiring harnesses are expensive because they're still made by hand; they're one of the last things to resist automation.