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Load switching with existing NEMA 6-20 receptacle in garage?

I'm currently scheduled to get my Model Y in the May-June 2022 timeframe and am assessing my at-home charging options. I'm retired and don't do daily long drives, so overnight charging on the NEMA 6-20 receptacle I already have installed in my garage is totally adequate for my needs. However, this receptacle was originally installed to power my table saw which I still use every week or two. I don't want to just add another NEMA 6-20 receptacle to this circuit and forget my car is plugged in and charging aand then turn on the saw. While I can plug the Tesla's charging cable in to this receptacle and leave it plugged in most of the time, and unplug it when I want to use my saw, I would prefer something simpler that didn't involve plugging and unplugging stuff. I'm wondering if I could simply install a 2-position switch in the feed to my receptacle, and then add another NEMA 6-20 receptacle to the other pole of this switch. That way I could leave both the saw and the car plugged in, but the switch would only allow one to be turned on at a time. Has anyone else tried a similar setup and, if so, do you have a link to a suitable switch? Also, can anyone think of any downside to this from the standpoint of running the car's charging through a switch?

P.S.: My 200 amp breaker panel is essentially full, otherwise I'd just add a new, dedicated Tesla charging circuit.
 

Sophias_dad

Active Member
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Jul 29, 2018
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Massachusetts
There are definitely switches that would do this job:


But keep in mind that to keep it to 'code', the breaker should be changed to a GFCI(for the EV), and that is fairly likely to trip when the saw is in use.

If it were me, I'd look hard at putting another circuit into your current panel, either by combining circuits or putting in some tandem breakers, or even putting in a cheap-ass subpanel where your current 6-20 is and maybe upgrading the wires(if needed!) to ones good enough for 40+ amps. A small subpanel is like $25(!), and you could be all-in for less than the cost of the switch above.
 
Thanks. I'll think about that Square D switch, but it is a bit more expensive than I was hoping. I agree with you on putting in another circuit, but right now almost all of the breakers in my panel are already tandem. It's not overloaded, but the electrician who wired it put in a lot of smaller circuits. I may be forced to try to combine several of them to free up room for a separate EV circuit. I appreciate your thoughts as I kick this can down the road.
 
Sophias_dad-
After I read your post I did some reading up on the GFCI requirement and it looks like it may only apply to higher amp circuits, like 50 amps. Do you know if that is so? I generally am safety-minded and wouldn't have a problem with putting in a GFCI breaker even if not required, but I have also heard that there is a documented history of them causing nuisance tripping. Any further thoughts on this?
 

Sophias_dad

Active Member
Supporting Member
Jul 29, 2018
2,224
2,532
Massachusetts
Sadly for you, Washington State has adopted the 2020 NEC (StackPath) and 2020 NEC has section
"625.54 Ground-Fault Circuit-Interrupter Protection for Personnel. All single-phase receptacles installed for the connection of electric vehicle charging that are rated 150 volts to ground or less, and 50 amperes or less shall have ground-fault circuit-interrupter protection for personnel."

So, yeah, it applies to your installation precisely. You could always ignore it.
 
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jcanoe

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Oct 2, 2020
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Maryland
GFCI protection is now required for all new installations of EV charging circuits that have a receptacle, not required for hard-wired EVSE. You don't have to add a GFCI to an existing circuit (although it would be a good idea.) If you remember to always turn off the power at the service panel before plugging or unplugging the electric vehicle service/supply equipment (EVSE) then there is no issue. The EVSE already has GFCI protection for the charging cable/connector. The GFCI for the circuit with a receptacle is designed to protect the user when plugging in or unplugging.
 
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ATPMSD

Active Member
Mar 12, 2021
1,317
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Atlanta, GA
If you happen to still have two standard 20-amp breakers side by side, the option below will give you a 240V 20-amp circuit plus two 120V 20-amp circuits in just those two slots.

 

ATPMSD

Active Member
Mar 12, 2021
1,317
1,203
Atlanta, GA
If you remember to always turn off the power at the service panel before plugging or unplugging the electric vehicle service/supply equipment (EVSE) then there is no issue.
However, this is not code and:

“Circuit breakers are designed as circuit protective devices. They are not intended for use as everyday switches. Dependent on load when operated a circuit breaker should tolerate 50 - 100 operations after which you may be in trouble.”
 
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jcanoe

Well-Known Member
Oct 2, 2020
5,501
6,011
Maryland
However, this is not code and:

“Circuit breakers are designed as circuit protective devices. They are not intended for use as everyday switches. Dependent on load when operated a circuit breaker should tolerate 50 - 100 operations after which you may be in trouble.”
I should have added that it is best to leave the EVSE plugged in as this keeps the plug and receptacle connection tight. If you leave the EVSE plugged in, rarely unplug then as long as you turn off the power at the service panel for those times when you need to unplug there is little to no risk of electrocution while handling the plug.
 

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