2020 NEC Equipment Ground for Ranges and Dryers Receptacle Replacement (Need Clarification)

[kwired]

We would also need 240v light bulbs.

which are sort of rare but do exist. They also could install SDS in the appliance to get 120 or any other voltage for that matter

All good points and thank you guys for taking my idea seriously.

The more I think about it, its got to be so they can use the same electronics / lights in gas or electric models.
But lots of electronic power supplies can handle 100-277V these days.


This sure needs to be looked into,
but I have seen ranges that dont have anything terminated on the neutral block.


They do make a E14 base bulb thats used in 240V ovens and microwaves:

https://www.usa.lighting.philips.com/prof/conventional-lamps-and-tubes/incandescent-lamps/domestic-appliances/appliance-oven-tubular/924196244440_NA/product

These days they probably have some hi temp LED oven lights anyways.


Just think for a second about how much #8/3 WG is pulled every year in new homes.
No new oven / range / stove uses that #8 neutral at over 2 amps, if at all.

Seen some ranges with no neutral conductors on the terminal block as well. most if not all were very basic ranges with no clock or digital controller and no oven light.

As far as any danger - is there much for data from electrocutions from this? I kind of doubt it.

That risk maybe does increase if the range is within reach of something grounded like another metal cabinet appliance or a sink. Otherwise most kitchens you are on a non conductive floor and if frame is at an elevated voltage to ground you will never even know it.

 

[vylia1990]

Would using a 2 pole GFCI breaker mitigate the danger of not having an EGC present at the 240v dryer or range outlet?

If so would the load neutral wire need to be landed on the GFCI or could it still be landed on the neutral bus bar?

 

[kwired]

Would using a 2 pole GFCI breaker mitigate the danger of not having an EGC present at the 240v dryer or range outlet?

If so would the load neutral wire need to be landed on the GFCI or could it still be landed on the neutral bus bar?

GFCI breaker would introduce nuisance tripping issues. Anytime something grounded contacts the appliance frame that is bonded to the neutral it should trip on N-G detection feature. Range sitting next to refrigerator could have frequent trips for no reason other than intermittent contact to one another. Same with washer and dryer (sort of not applicable to this thread, yet the dryer has same rules here) washer shakes a little during spin mode and contacts dryer - trips dryer GFCI.

 

[tortuga]

Would using a 2 pole GFCI breaker mitigate the danger of not having an EGC present at the 240v dryer or range outlet?

Honestly the only sensible solution to this is to start asking for and create demand for 240V ranges and dryers here in the US.
It seems like a waste to rewire every SE cable fed 10-30 dryer outlet in the US and probably Canada when the SAME manufacturers make 230V models for export for every other country in world.

I have never looked at a dryer motor but it seems unlike a washer in that its a single speed 120V motor and might be very simple to convert to 240V.

 

[vylia1990]

GFCI breaker would introduce nuisance tripping issues. Anytime something grounded contacts the appliance frame that is bonded to the neutral it should trip on N-G detection feature. Range sitting next to refrigerator could have frequent trips for no reason other than intermittent contact to one another. Same with washer and dryer (sort of not applicable to this thread, yet the dryer has same rules here) washer shakes a little during spin mode and contacts dryer - trips dryer GFCI.

I was under the impression a two pole GFCI would trip if the current from one of the hots was unbalanced. Sorry for my ignorance but wouldn't that preclude a breaker trip from just contacting the frame unless the frame was energized, in which case the GFI is doing what it's supposed to?

 

[retirede]

I was under the impression a two pole GFCI would trip if the current from one of the hots was unbalanced. Sorry for my ignorance but wouldn't that preclude a breaker trip from just contacting the frame unless the frame was energized, in which case the GFI is doing what it's supposed to?

The current flowing on the entire circuit (neutral included) must be balanced. Otherwise, it could not power the 120V portion of the load.

 

[wwhitney]

406.4(D)(1)(c) does not appear to be limited to NEMA 5-15 and 5-20 receptacles. So it would appear to allow replacing a NEMA 10-30 or 10-50 receptacle supplied by an ungrounded 120V/240V circuit with a NEMA 14-30 or 14-50 receptacle with the EGC pin left floating, provided that the receptacle has upstream GFCI, i.e. at the breaker.

Then if a stove or dryer with 4-wire plug and without internal neutral-case bond is installed on such a receptacle, the case would end up floating, and there would be no nuisance tripping issue from other case-ground contact.

However, it appears this would violate 250.114(3) and 250.140, which do not have any provisions for leaving the metal case floating.

Cheers, Wayne

 

[gene6]

Where would the violation of NEC be if you use a standard 6-30/6-50 on old SE cable?
Not that I would ever do this, but I have been told there there is nothing in the NEC that prohibits nor limits current from flowing on a equipment ground. Just take a standard occupancy sensor as an example.

 

[wwhitney]

Where would the violation of NEC be if you use a standard 6-30/6-50 on old SE cable?

You could absolutely do this if you use the 3rd wire as an EGC. But then you need a 240V only dryer or range. Which are available at least from European manufacturers.

Cheers, Wayne

 

[gene6]

But then you need a 240V only dryer or range. Which are available at least from European manufacturers.

No I am talking about where the NEC ends, its the receptacle outlet. The inspector would be forced to pass it. A standard 120/240 dryer would work fine on a 6-30 and there is no NEC violation to point at that I can find. Same as a occupancy sensor they use the EGC for power

 

[wwhitney]

That would be contrary to the product's installation instructions, which require the neutral-chassis strap when there's no EGC.

Yes, in accordance with 250.140, as I cited. Wayne

 

[gene6]

Where is that quote from did I miss something?
What I am proposing is a 1) Installing a 6-30 receptacle on a 3 wire SE cable is code legal. and 2) 6-30 receptacle (no neutral) meets 250.140 it provides an equipment grounding conductor that attaches to the frame.
Not saying i'd do that, but the code does not prohibit current on a equipment grounding conductor, I submit an occupancy sensor as an example.

 

[tortuga]

I got tingled pretty good one time working on a gound bar in a panel, I was baffled figured somthing was shorted, it was a office building and every room had occupancy sensors that put a few ma on the grounding conductor (wired before the neutral to switch requirement) all those sensors addup to somthing like just under a amp. I remember trying to find a code section those sensors violated and came up cold. Always treat stuff like its hot unless you can confirm otherwise.

 

[kwired]

I was under the impression a two pole GFCI would trip if the current from one of the hots was unbalanced. Sorry for my ignorance but wouldn't that preclude a breaker trip from just contacting the frame unless the frame was energized, in which case the GFI is doing what it's supposed to?

GFCI's pass the conductors being protected through a current transformer. Simple two wire - what goes out on conductor 1 must come back on conductor 2, if not it creates a voltage on the CT, if that voltage is high enough (class A GFCI's supposed to trip when imbalance is over 4-6 mA)then it initiates the trip process.

Multiwire circuits are really no different, they pass all conductors (including neutral) through the CT, could be 120/240 single phase or even three phase four wire. If 10 amps of current goes out on conductor A, it must come back on any combination of the other conductors to give a zero net on the CT. If 10 mA comes back to source outside the monitored conductors, most cases will be an EGC but can take path via anything including ungrounded conductor of another circuit, it will cause voltage to develop in the CT and initiate trip sequence.

These GFCI's also have a feature where they inject a signal into the protected neutral and if neutral happens to fault to something else that creates a current that passes back through the source and eventually back through the supply side neutral of the GFCI device, it will be enough current but only one conductor is carrying it through the CT so it initiates the trip sequence - this why if the appliance is grounded via the neutral that any inadvertent connection to other ground potential by that appliance cabinet will trip via this N-G fault protection feature whether that neutral is carrying any actual working load or not.

 

[ESolar]

Where is that quote from did I miss something?
What I am proposing is a 1) Installing a 6-30 receptacle on a 3 wire SE cable is code legal. and 2) 6-30 receptacle (no neutral) meets 250.140 it provides an equipment grounding conductor that attaches to the frame.
Not saying i'd do that, but the code does not prohibit current on a equipment grounding conductor, I submit an occupancy sensor as an example.

Caveat: I am not the expert that Wayne and others here are. EV chargers are also an example. A Tesla Wall Charger running at 240 has two hots and a ground - no neutral. I just repurposed a 10/2 with bare ground (all solid conductors) that was never code compliant for a (typical) dryer (because it was connected to a 10-30P with bare ground). I did a run of 10/3 THHN from the dryer outlet to a new 6-30R in the garage for an EV plug. There is another thread discussing my reasoning for that choice. I could find no code issue with wiring a 6-30 with 10/3. If there is one please shout out. I put a lay in lug in the box for a 10 AWG ground pigtail and ran EMT. Attached #8 SOOW and 6-30P to a Tesla Wall Charger that plugs into the 6-30R. A new 14-30 8/3 NM-B was installed for the dryer.

That 10/2 is a single run from the Main. Perhaps I should head back out to check to see if the ground is connected to the neutral (although they are bonded at the Main) because it was wired to a 10-30R.

On another note: The common 10-30R faceplate is metal. Those 10-30Rs without an EGC don't seem like a great idea - even the box with metal faceplate and no appliance attached presents a potetnial hazard.

 

[kwired]

Caveat: I am not the expert that Wayne and others here are. EV chargers are also an example. A Tesla Wall Charger running at 240 has two hots and a ground - no neutral. I just repurposed a 10/2 with bare ground (all solid conductors) that was never code compliant for a (typical) dryer (because it was connected to a 10-30P with bare ground). I did a run of 10/3 THHN from the dryer outlet to a new 6-30R in the garage for an EV plug. There is another thread discussing my reasoning for that choice. I could find no code issue with wiring a 6-30 with 10/3. If there is one please shout out. I put a lay in lug in the box for a 10 AWG ground pigtail and ran EMT. Attached #8 SOOW and 6-30P to a Tesla Wall Charger that plugs into the 6-30R. A new 14-30 8/3 NM-B was installed for the dryer.

That 10/2 is a single run from the Main. Perhaps I should head back out to check to see if the ground is connected to the neutral (although they are bonded at the Main) because it was wired to a 10-30R.

On another note: The common 10-30R faceplate is metal. Those 10-30Rs without an EGC don't seem like a great idea - even the box with metal faceplate and no appliance attached presents a potetnial hazard.

Well technically you are using that white conductor as an EGC, so it should be green or bare, to comply with code. Functionality wise, I have no issue with it. The electrons in the conductor don't care what color insulation is when it comes to determining where current can or should flow.

 

[tortuga]

Agreed the electrons dont care, tape it green and call it a day.
The loop hole pointed out in this tread is most interesting. A neutral can't ever be used as an EGC but the opposite is more vague.

 

[ESolar]

Well technically you are using that white conductor as an EGC, so it should be green or bare, to comply with code. Functionality wise, I have no issue with it. The electrons in the conductor don't care what color insulation is when it comes to determining where current can or should flow.

In my case the 10-30 was wired with a #10 bare neutral, and black and white wires (all solid). In other words, the circuit was never code compliant. That prompted my decision to repurpose it for an EV. I colored the white red with a permenant marker. I tied into that circuit with 3 x #10 stranded THHN black, red and white (no green was available). I colored the white green with a permenant marker. A new dryer ciruit was run with #8.

 

[kwired]

In my case the 10-30 was wired with a #10 bare neutral, and black and white wires (all solid). In other words, the circuit was never code compliant. That prompted my decision to repurpose it for an EV. I colored the white red with a permenant marker. I tied into that circuit with 3 x #10 stranded THHN black, red and white (no green was available). I colored the white green with a permenant marker. A new dryer ciruit was run with #8.

When you said 10-3 most would consider that to be a cable with black, red, white, and if it had the WG suffix also would have a bare or green conductor.

Flexible cord however typically would be called 10-3 with black white green conductors and never has a WG suffix on flexible cord.

10-30 would be a cable that definitely needs ampacity adjustment however for number of current carrying conductors

To comply with NEC it is permitted to identify a white conductor in a cable assembly as a non grounded conductor in cases where no grounding conductor is needed. NEC never permits re-identifying a conductor as an EGC, those must always be bare, green or green with yellow stripes, and for most part is not allowed to re-identify any those three for any other purpose either.

That said, the electrons still don't care what color insulation is, it will perform as it has been connected, any color requirement is only for identification purpose.

 

[tortuga]

NEC never permits re-identifying a conductor as an EGC, those must always be bare, green or green with yellow stripes, and for most part is not allowed to re-identify any those three for any other purpose either.

It doesn't explicitly prohibit it either. I had an old building I was remodeling (not rewiring) that had tons of 14/3 'BX' (type AC cable) with no egc and it was pre 1960's so before they added the aluminum bonding strip, and the red wire was no longer needed/used. i stripped the reds off as far ass I could and tied them to the metal boxes, inspector was pleased with that.