Downsized neutral for dryer circuit

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augie47 said:
210.19(A)(3) Exception somewhat shoots that in the foot..... it does not apply to dryers but does show the neutral ona branch circuit does not always have to be sized by the ungrounded conductors.
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Thanks for pointing that out. But if that's the only example, then I would say rather that it's the exception that proves the rule.

Cheers, Wayne
 
Jerramundi said:
A situation that I regularly enjoy mocking - guys run out of what they need and just try to push out "what's on the truck."
Happened to me a few times where the GC drops off a milk crate of old wire he had collecting dust in the garage and expects me to use it.
And now I'm the bad guy if I resist the almighty GC.

If I run out of what I need, I cope w/ the headache of having to run to the Depot or supply house. But at the same time, I get it, because it's probably why I have thousands of dollars sitting on my shelves. You gotta be smart and find a way to SAFELY utilize your backstock.

Still, ultimately, the cost per foot difference of #12 and #10 is negligible in this case. You're talking about saving $3-$5, maybe.
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Mock if you wish. Lady really needed to do laundry - 3 teenagers make for lots of dirty clothes. Apparently, the dryer had been without power for four days before she called. Sometimes, you gotta make it work with what you have. He's headed over this afternoon to swap in some #10 for the neutral.


SceneryDriver
 
SceneryDriver said:
Mock if you wish. Lady really needed to do laundry - 3 teenagers make for lots of dirty clothes. Apparently, the dryer had been without power for four days before she called. Sometimes, you gotta make it work with what you have. He's headed over this afternoon to swap in some #10 for the neutral.


SceneryDriver
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If you can make it work with what you have AND it's code compliant, then I have no qualms with you good sir. Good day. 😂

In all honesty, it wouldn't be the first time I've seen some funky solutions and pretending like that's not common, is just a bunch of hot air.
My favorite one to date has to be using all thread couplings off a stick of IMC/RMC to link pieces of FMC 😂😂
I don't utilize it, other than one time where I was working for someone else and saw him do it,
but you gotta admit, even though it's wrong, it's clever.
 
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I have a slightly different wrinkle on the OP's question:

My customer just bought his first all-electric dryer and so I'm installing a new branch circuit for it. The mfr's label says the rating is 26A, and if it was an AC or EV charger, I'd automatically use #8 cu on a 30A breaker (continuous duty would be likely)...I wouldn't think to do that for a dryer, but the installation instructions for this model (LG DLEX3900B) says this:

"If the branch circuit to appliance is 15 ft. (4.5 m) or less in length, use UL (Underwriters Laboratories) listed No.-10 AWG wire (copper wire only), or as required by local codes. If over 15 ft. (4.5 m), use UL-listed No.-8 AWG wire (copper wire only), or as required by local codes."

The length of this new circuit is about 50 ft, and so I'm inclined to comply (grumpily) with their "suggestion". I suppose I could argue about the semantics of "OR as required by local codes", which I'm pretty sure would not REQUIRE the #8, but if my customer ever has to make a warranty claim, I don't want to give LG the opportunity to deny it based on a "non compliant installation".

That brings me back to the question of the "downsized" neutral...in my case, I would prefer to use a #10 neutral, and "upsize" only the 2 ungrounded CCC's, and I'd like y'all's take on whether or not that would meet code, AND if you think it would also satisfy the mfr's installation requirement, or if you would upsize the neutral to #8 also.

Thanks in advance...
 
My off the cuff answer is that the upsized ungrounded conductors trigger the requirement to increase the size of the EGC, and that the neutral can be no smaller then the EGC.....

What a stupid manufacturer recommendation. Voltage drop at 50 feet is perhaps 1%. Increasing the size of the circuit conductors triggers an increase in size of the EGC, which means you can't use off the shelf cable.

Basically to install per manufacturer recommendation you need to use conduit or get custom cables made. I'd be inclined to ignore this recommendation, but it might have warranty implications.

Jon
 
ron m said:
I have a slightly different wrinkle on the OP's question:

My customer just bought his first all-electric dryer and so I'm installing a new branch circuit for it. The mfr's label says the rating is 26A, and if it was an AC or EV charger, I'd automatically use #8 cu on a 30A breaker (continuous duty would be likely)...I wouldn't think to do that for a dryer, but the installation instructions for this model (LG DLEX3900B) says this:

"If the branch circuit to appliance is 15 ft. (4.5 m) or less in length, use UL (Underwriters Laboratories) listed No.-10 AWG wire (copper wire only), or as required by local codes. If over 15 ft. (4.5 m), use UL-listed No.-8 AWG wire (copper wire only), or as required by local codes."

The length of this new circuit is about 50 ft, and so I'm inclined to comply (grumpily) with their "suggestion". I suppose I could argue about the semantics of "OR as required by local codes", which I'm pretty sure would not REQUIRE the #8, but if my customer ever has to make a warranty claim, I don't want to give LG the opportunity to deny it based on a "non compliant installation".

That brings me back to the question of the "downsized" neutral...in my case, I would prefer to use a #10 neutral, and "upsize" only the 2 ungrounded CCC's, and I'd like y'all's take on whether or not that would meet code, AND if you think it would also satisfy the mfr's installation requirement, or if you would upsize the neutral to #8 also.

Thanks in advance...
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Who reads the instructions? Just install number 10.
 
wwhitney said:
That is true for feeders per 215.2(A)(2), but a quick search of Article 210 turned up no corresponding requirement for branch circuits.

Cheers, Wayne
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Ok but devil's advocating a bit here:. You seem to be assuming that unless otherwise stated, the neutral must be full sized. The code is a permissive document as you know. Wouldn't the default be sized to the load served?
 
electrofelon said:
Ok but devil's advocating a bit here:. You seem to be assuming that unless otherwise stated, the neutral must be full sized. The code is a permissive document as you know. Wouldn't the default be sized to the load served?
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Good question. While Part III of Article 220, specifically 220.61, discusses the neutral load on a feeder, there is nothing like that in Part II on branch circuits. But is there 120/240V equipment that has a rating or nameplate specifying separate L-L and L-N amp values? If the nameplate just says "30A" then it's not specifying, and all the circuit conductors would need a 30A rating.

A related question is 240.4, I don't see anything in it that actually permits the neutral of a feeder to be protected at above its ampacity, which it would be if the feeder neutral conductor size is reduced, as is common.

Cheers, Wayne
 
ron m said:
I have a slightly different wrinkle on the OP's question:

My customer just bought his first all-electric dryer and so I'm installing a new branch circuit for it. The mfr's label says the rating is 26A, and if it was an AC or EV charger, I'd automatically use #8 cu on a 30A breaker (continuous duty would be likely)...I wouldn't think to do that for a dryer, but the installation instructions for this model (LG DLEX3900B) says this:

"If the branch circuit to appliance is 15 ft. (4.5 m) or less in length, use UL (Underwriters Laboratories) listed No.-10 AWG wire (copper wire only), or as required by local codes. If over 15 ft. (4.5 m), use UL-listed No.-8 AWG wire (copper wire only), or as required by local codes."

The length of this new circuit is about 50 ft, and so I'm inclined to comply (grumpily) with their "suggestion". I suppose I could argue about the semantics of "OR as required by local codes", which I'm pretty sure would not REQUIRE the #8, but if my customer ever has to make a warranty claim, I don't want to give LG the opportunity to deny it based on a "non compliant installation".

That brings me back to the question of the "downsized" neutral...in my case, I would prefer to use a #10 neutral, and "upsize" only the 2 ungrounded CCC's, and I'd like y'all's take on whether or not that would meet code, AND if you think it would also satisfy the mfr's installation requirement, or if you would upsize the neutral to #8 also.

Thanks in advance...
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Run a small sub panel within 15’ Then you can still use 10-3 the whole way to the panel and to the 15’ requirement.
So does what the manufacture state get them from all warranty issue if installed don’t on an existing circuit that is farther than 15’
If so they are just being sneaky and trying to get away from fixing there crappy item (LG SUCKS)
 
wwhitney said:
Good question. While Part III of Article 220, specifically 220.61, discusses the neutral load on a feeder, there is nothing like that in Part II on branch circuits. But is there 120/240V equipment that has a rating or nameplate specifying separate L-L and L-N amp values? If the nameplate just says "30A" then it's not specifying, and all the circuit conductors would need a 30A rating.

A related question is 240.4, I don't see anything in it that actually permits the neutral of a feeder to be protected at above its ampacity, which it would be if the feeder neutral conductor size is reduced, as is common.

Cheers, Wayne
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Fair point that the device/appliance would need to state what the neutral load is rather than one just assuming .
 
winnie said:
the upsized ungrounded conductors trigger the requirement to increase the size of the EGC
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Around here, the EGC size for a branch circuit is still determined by the OCPD rating, so I'm ok with #10 EGC, which would match my proposed neutral
winnie said:
to install per manufacturer recommendation you need to use conduit
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I should have mentioned in my post that this new BC is in conduit
AC\DC said:
Run a small sub panel within 15’ Then you can still use 10-3 the whole way to the panel and to the 15’ requirement.
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Clever idea, thanks :LOL: ...It won't work for this situation, and if it did, the likely cost in added labor and materials would probably be more than even upgrading all 3 CCCs to #8
AC\DC said:
So does what the manufacture state get them from all warranty issue if installed don’t on an existing circuit that is farther than 15’
If so they are just being sneaky and trying to get away from fixing there crappy item (LG SUCKS)
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Interesting point 🤔. The instructions and labeling clearly allow installation on existing 3-wire dryer circuits, but their "upgrade requirement" makes no distinction between new circuits and existing...and if one was to "upgrade" the wire size of an existing 3-wire circuit (assuming conduit), is it still an existing circuit? I'd say no, and therefore needs an EGC and 4-wire recept + cord
 
I'm kind of late to this party, but I don't think that the small conductor rule has been mentioned, 240.4(D)(5), which seems to make the whole conversation moot.
 
I believe that electric dryers only use the grounded conductor to supply 120 volts to drum motor, drum luminare, controls & timer. Guessing we'll under 10 amps but the few times that I ran EMT to feed a 30 amp dryer receptacle always used a #10 white conductor for the grounded conductor. Did have one homeowner that used the dryer receptacle to power up a small welder but not sure if any welders need a grounded conductor.
 
FWIW when I have a pipe run to a dryer, which is typical of the labs I often do, I run a #12 for the neutral. In addition to the #12 not being necessary, I never seem to need white #10 for anything else so I dont bother getting roll just for a few dryers here and there. My home dryer is piped and has a #12 white also. I wonder if 14-30 receps are typically rated for a #12?
 
Forget all the loads on the neutral. If the feeder needs the equipment grounding conductor to be sized no smaller than the equipment grounding conductor what makes anyone believe that a smaller neutral would be allowed in a branch circuit. For the same reason as feeders the neutral would need to clear a line to neutral fault. The nec chose a #10 equipment grounding conductor for a reason.
 
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