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UMC, Corded & Wall Chargers do not use Neutral?

Zinfandel

Member
May 20, 2018
33
93
Lincoln, MA
I am installing wiring to initially support a NEMA 14-50 outlet but later a Tesla Wall Charger. I want to oversize the wire gauge for the NEMA 14-50. If NONE of Tesla's home chargers use the neutral leg, I will save money and time by not including the neutral wire. Am I understanding this correctly?
 

JasJ

Member
Jan 26, 2017
421
485
Houston, TX
True, but if you're running a 14-50 first, run a thinner/cheaper (but appropriate for 50A) gauge neutral so you are not violating code by installing an outlet without a neutral, could be quite dangerous for non-Tesla use.
 

boaterva

Supporting Member
Supporting Member
Apr 2, 2016
7,574
3,746
Northern Virginia, USA
Yes, BUT a 14-50 still needs the neutral wire to be installed to code since a 14-50 itself needs the neutral wire. See Flasher's FAQ in my sig for more.

Anything that is STRICTLY 240 VAC does not need it, since you are using only the two legs of the 240 supply. Anything that could theoretically peel off one of the legs and supply 120VAC to something (using the neutral) has to have a neutral, and that's why the 14-50 requires a neutral.

SO, a 14-50 needs a neutral, BUT wires run strictly for an HPWC do not. Since there is no 120 use there and can't be one.
 

Malbrough

Member
Nov 30, 2017
89
111
Oklahoma
Correct. For a the HPWC, some installers in my area use Romex 6/2 (has black, white and ground) and they just mark the white wire with red tape or paint on each end to designate it as a power phase and not neutral. Or they use 6/3 (has black, white, red, and ground) and not use the white wire. I think it just depends on what they have in the truck when they show up for the job. Both of those wires are rated at 55 amps.

I would think that for the NEMA 14-50 on a 50 amp breaker, they would need to install all 3 conductor wires and the ground to meet code. It's not that much more expensive for 6/3 compared to 6/2 (looking at Lowe's website). The labor is what costs the most. To install a NEMA 14-50 near the breaker box here costs around $250, last I checked.
 

teethdood

Member
Jan 30, 2017
396
524
Visalia, California
Don't cheap out. Problem is that someone else in your family or the next homeowner will not know this and plug in another device that needs the neutral to work safely. Kind of like installing a 3-prong 120V adapter to plug into an old 2-prong outlet. It'll work, but safety is not guaranteed.
 

Derek Kessler

Active Member
Apr 15, 2016
1,193
1,806
Cincinnati
You are correct that a 14-50 plug does have a neutral line and that Tesla chargers do not use it. But if you are installing an outlet you ABSOLUTELY MUST install it with the correct wiring. Just because you don't need it now for your car doesn't mean somebody else won't later down the line.

This level of electrical install is easy, but the kind of power we're talking about is not to be toyed with. Do it right or don't do it at all.
 
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ewoodrick

Well-Known Member
Apr 13, 2018
5,285
3,735
Buford, GA
You are correct that a 14-50 plug does have a neutral line and that Tesla chargers do not use it. But if you are installing an outlet you ABSOLUTELY MUST install it with the correct wiring. Just because you don't need it now for your car doesn't mean somebody else won't later down the line.

This level of electrical install is easy, but the kind of power we're talking about is not to be toyed with. Do it right or don't do it at all.


It's pretty common for folks with single air conditioner campers to use an adapter to plug into a NEMA 14-50 to run the camper. This requires the ground to get 110V. If it is not there, well, I don't want to see the results.

Just do it right. You spent $100k+ for the car, don't skimp on $50.
 
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PWlakewood

Active Member
Jan 9, 2019
1,779
899
US
So just cap the white wire off then? I just purchased the Tesla home charger and I already have a 14-50 outlet that is wired to code which uses the white wire and I will be adding a 14-50 plug instead of hardwiring the charger.
 

ckoval7

Mild One
Sep 19, 2018
665
601
Maryland
So just cap the white wire off then? I just purchased the Tesla home charger and I already have a 14-50 outlet that is wired to code which uses the white wire and I will be adding a 14-50 plug instead of hardwiring the charger.
If the outlet is going to exist, it must be wired correctly. Hook up the neutral with the appropriate sized wire and don't worry about what the UMC does/doesn't make use of.
 

PWlakewood

Active Member
Jan 9, 2019
1,779
899
US
If the outlet is going to exist, it must be wired correctly. Hook up the neutral with the appropriate sized wire and don't worry about what the UMC does/doesn't make use of.

Yes the outlet I had installed will stay that way if/when we sell one day. My question was do I just cap off the white wire that in comes with the cord that I will be using?
 

Supershaun

New Member
Sep 25, 2020
2
0
Florida
I am installing wiring to initially support a NEMA 14-50 outlet but later a Tesla Wall Charger. I want to oversize the wire gauge for the NEMA 14-50. If NONE of Tesla's home chargers use the neutral leg, I will save money and time by not including the neutral wire. Am I understanding this correctly?


The netural is for AC power and ground is for DC power. The issue is if someone uses the 220v for a 120 with a splitter etc and runs a AC item without a netural wire the power has nowhere else to go. The netrual is a return of power and is constant. So if you plug in that AC item and it gets a surge of power etc it will cause an imbalance of power and can cause equipment issues and personal harm because the power has no way to return. If you run a DC item the ground is a fail safe to take power if it has no where to go either from over powered or say you some how make contact to the live wire if there is no ground then you become the ground. I would recommend connecting the correct Nema the right way. Or use a different that doesn't have 4 wires. This way you won't be able to buy pig tails that would make incorrect splits to 120v etc.
 

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