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Convert NEMA 5-20 to 6-20?

Kirby64

Member
Jun 28, 2018
485
0
Austin, TX
The equations are a bit more complex that this, because it depends on the wire run length.

However, 10 gauge will have less electric loss than 12 gauge, and for anything but a short cable run, it may start to heat up at 240v-20a (240v-16A continuous) whereas it wouldn't at 120v-20a.

You're wrong. There is no difference in heat generated from a 120V-20A outlet that pulls 16A continuously vs. a 240V-20A outlet that pulls 16A continuously. Both wires (hot and neutral, or hot1 and hot2) are moving 16 amps of current continuously in either scenario, so the losses from heat are identical.
 

Rocky_H

Well-Known Member
Feb 19, 2015
5,811
4
Boise, ID
You're wrong. There is no difference in heat generated from a 120V-20A outlet that pulls 16A continuously vs. a 240V-20A outlet that pulls 16A continuously. Both wires (hot and neutral, or hot1 and hot2) are moving 16 amps of current continuously in either scenario, so the losses from heat are identical.
Yep--that's why the equation used for heat dissipated in a wiring run is current squared times resistance. Voltage is not in there.
 

KermitK

Member
Feb 13, 2019
22
0
EAST AMHERST
I ask because I get a dedicated 5-20 at work but it's maddening how slow it is. If only I could somehow squeeze just a little more juice from the plug. :)
 

ZOMGVTEK

Member
May 19, 2015
558
0
'Merica
If you just have one outlet on a 5-20, it’s not very complex to change it to a 6-20. You need one extra space in the panel. Change the breaker to a double pole, tape the white wire red and move it to the other leg of the breaker, pull the 5-20 out, tape the wire wire red, and pop in a 6-20. This is most likely a 10-20 minute job for an electrician, and NEC compliant. But again, you can’t have anything else on that circuit. If you have a string of outlets on that circuit, you could technically change them all to 6-20’s as long as they are duplex. Single outlets must be on dedicated circuits. If you’re unaware of an extra outlet that’s on that same circuit, be aware you will get 240V on that unknown outlet...

A 6-20 will give you around 130% higher charge power, since the fixed overhead is already accounted for.
 

eprosenx

Active Member
May 30, 2018
2,064
0
Beaverton, OR
If you just have one outlet on a 5-20, it’s not very complex to change it to a 6-20. You need one extra space in the panel. Change the breaker to a double pole, tape the white wire red and move it to the other leg of the breaker, pull the 5-20 out, tape the wire wire red, and pop in a 6-20. This is most likely a 10-20 minute job for an electrician, and NEC compliant. But again, you can’t have anything else on that circuit. If you have a string of outlets on that circuit, you could technically change them all to 6-20’s as long as they are duplex. Single outlets must be on dedicated circuits. If you’re unaware of an extra outlet that’s on that same circuit, be aware you will get 240V on that unknown outlet...

A 6-20 will give you around 130% higher charge power, since the fixed overhead is already accounted for.

It may or may not be as simple as described above.

In a commercial setting there is a good chance that the electrical system is 208/120v three phase. So converting it might still be possible, but you would only get 208v vs. 240 (still a great upgrade).

There is also a good chance that the neutral is shared in which case you can’t just as easily convert it to 208v/240v.

Still worth trying though!

P.S. Did you at least get the 5-20 adapter from Tesla vs just using the 5-15 one that came with the car? That also makes a big difference (but 208v/240v is way better still).
 

brkaus

Well-Known Member
Jul 8, 2014
7,627
0
Austin, TX
If you have a single 5-20 outlet on a circuit, you must make a change at the panel to charge at 6-20, right? I saw on another post someone said to make or find an adapter and the UMC would pick up on the voltage change but don't see how that could work. I found this adapter:

https://www.amazon.com/gp/aw/d/B07TJZ29JJ

What is it's purpose?

I’m pretty confused by the item you linked. The title and the description are different. Title referring to 6-series (240v) and description referring to 5-series (120v)

yes, the connection in the panel needs to change to convert to 240v (and the outlet should be changed too).

I ask because I get a dedicated 5-20 at work but it's maddening how slow it is. If only I could somehow squeeze just a little more juice from the plug. :)

Did you purchase a 5-20 adapter from Tesla? Or are you using the included 5-15?
 
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gfunkdave

Member
Aug 10, 2016
120
0
Portland, ME
I’m pretty confused by the item you linked. The title and the description are different. Title referring to 6-series (240v) and description referring to 5-series (120v)

What an odd adapter. Lets you plug a 120V (5-15 or 5-20) plug into a 6-20 outlet. I'm not sure why you'd need/want such a thing.
 

KermitK

Member
Feb 13, 2019
22
0
EAST AMHERST
I’m pretty confused by the item you linked. The title and the description are different. Title referring to 6-series (240v) and description referring to 5-series (120v)

yes, the connection in the panel needs to change to convert to 240v (and the outlet should be changed too).



Did you purchase a 5-20 adapter from Tesla? Or are you using the included 5-15?

Thanks. Yes I did get the 5-20, that too my charge rate from 5mph to 7mph. Unfortunately I have no access to the panel so this is as good as it gets. Although I do wish I could nudge it up to 18a, pretty sure that continuous load would be fine when the parking area dips down to -10f during the winter.
 

brkaus

Well-Known Member
Jul 8, 2014
7,627
0
Austin, TX
Thanks. Yes I did get the 5-20, that too my charge rate from 5mph to 7mph. Unfortunately I have no access to the panel so this is as good as it gets. Although I do wish I could nudge it up to 18a, pretty sure that continuous load would be fine when the parking area dips down to -10f during the winter.

those extra 2a would make the heat generated within the circuit go up by 25%.

sure, might be ok. But I worked as a firefighter for 3-4 years... I wouldn’t do it.
 

davewill

Active Member
Feb 5, 2014
1,802
0
San Diego, CA, US
What an odd adapter. Lets you plug a 120V (5-15 or 5-20) plug into a 6-20 outlet. I'm not sure why you'd need/want such a thing.
The description says it turns a 6-20 into a 6-15/20 combo so you can plug a 6-15 plug into a 6-20 outlet. However the description and the picture show that it turns a 5-20 into 5-15/20 combo which would let you plug a 5-15 into a 5-20 outlet, not that I've ever seen a 5-20 that wasn't already a combo outlet.

Your guess is as good as mine which you would receive if you ordered it.
 
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DopeGhoti

Active Member
Aug 28, 2019
1,210
0
Phoenix, AZ
My workplace provides 5-15/5-20 outlets, and one hotly (hah!) contested 6-20 which runs at ~209V one-phase. the difference in charging between the 5-15 and 5-20 is perhaps 1MPH of charging rate; but the 6-20 easily doubles the charging rate of the 5-20.
 

Rocky_H

Well-Known Member
Feb 19, 2015
5,811
4
Boise, ID
I found this adapter:
I’m pretty confused by the item you linked. The title and the description are different. Title referring to 6-series (240v) and description referring to 5-series (120v)
The description says it turns a 6-20 into a 6-15/20 combo so you can plug a 6-15 plug into a 6-20 outlet. However the description and the picture show that it turns a 5-20 into 5-15/20 combo which would let you plug a 5-15 into a 5-20 outlet, not that I've ever seen a 5-20 that wasn't already a combo outlet.

Your guess is as good as mine which you would receive if you ordered it.
Yeah...I wouldn't dare order that since the person selling it doesn't even have any idea what it is.
 

Mobsidian

Member
Oct 31, 2017
135
0
Ajax, ON
Was wondering if this can be done on outdoor plugs that have GFCI? if so, do they make 6-20 plugs with GFCI? I'm planning to do this since I park outside and I know the 2 outdoor plugs are on one breaker and nothing else. Yeah I won't be able to use those plugs for anything else (unless I get an adapter maybe?) but I'll still have the 5-15 in the garage. Any advice would be helpful, thanks.
 

Kirby64

Member
Jun 28, 2018
485
0
Austin, TX
Was wondering if this can be done on outdoor plugs that have GFCI? if so, do they make 6-20 plugs with GFCI? I'm planning to do this since I park outside and I know the 2 outdoor plugs are on one breaker and nothing else. Yeah I won't be able to use those plugs for anything else (unless I get an adapter maybe?) but I'll still have the 5-15 in the garage. Any advice would be helpful, thanks.

You use a GFCI breaker in that scenario. If you have GFCI outlets currently, replace the breaker upstream with a GFCI breaker and swap to standard boring NEMA 6-20 outlets. If you're converting a circuit that has 2 outlets attached to be used for a dedicated EV charger, I'd recommend disconnecting one of the two outdoor plugs. Since the EV will be using 100% of the outlet, anything else connected to it would be pulling too much current.
 
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Mobsidian

Member
Oct 31, 2017
135
0
Ajax, ON
You use a GFCI breaker in that scenario. If you have GFCI outlets currently, replace the breaker upstream with a GFCI breaker and swap to standard boring NEMA 6-20 outlets. If you're converting a circuit that has 2 outlets attached to be used for a dedicated EV charger, I'd recommend disconnecting one of the two outdoor plugs. Since the EV will be using 100% of the outlet, anything else connected to it would be pulling too much current.
Gotcha, thanks! I'll likely remove one of them. Another thing, those plugs are maybe 40 feet from the driveway so I'll be using an extension cord, any issues with that? Do I need to shelter it somehow from rain and snow? Also, any suggestions on securing the charger and extension so no one can steal it?
 

brkaus

Well-Known Member
Jul 8, 2014
7,627
0
Austin, TX
Was wondering if this can be done on outdoor plugs that have GFCI? if so, do they make 6-20 plugs with GFCI? I'm planning to do this since I park outside and I know the 2 outdoor plugs are on one breaker and nothing else. Yeah I won't be able to use those plugs for anything else (unless I get an adapter maybe?) but I'll still have the 5-15 in the garage. Any advice would be helpful, thanks.

What @Kirby64 said. I'll add - there is no simple adaptor for 6-20 (240v) to 5-15 (120v).

Not sure about Canada rules, but NEC does require outdoor outlets. Not sure if 240v counts.
 

Kirby64

Member
Jun 28, 2018
485
0
Austin, TX
Gotcha, thanks! I'll likely remove one of them. Another thing, those plugs are maybe 40 feet from the driveway so I'll be using an extension cord, any issues with that? Do I need to shelter it somehow from rain and snow? Also, any suggestions on securing the charger and extension so no one can steal it?

Using an extension cord isn't really recommended... most folks will warn you against it. If you do use one, then you want a beefy extension cord (10 gauge would be ideal for a NEMA 6-20), and it needs to be definitely rain/snow sheltered. The UMC itself should be fine as long as it's not buried in the snow, but the cord plug itself needs to be somewhat sheltered.

As for theft... well, I don't know, put it in a box?
 
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Mobsidian

Member
Oct 31, 2017
135
0
Ajax, ON
Thanks Kirby. Last question. The wires from the panel box are 14/2. Is that okay for 6-15? I know it’s not enough for 6-20 unfortunately.