Can I install a 240 Volt NEMA 14-30 outlet off my 30 Amp garage subpanel?

[sewing1]

I've ordered a Model Y LR AWD.

I have a 100 Amp electrical service panel in my house basement. In my detached garage I have a 30 Amp subpanel that currently contains two 20 amp and one 15 amp circuit breakers for the lighting and outlets.

I'm thinking I could have an electrician install a 30 Amp breaker in the garage subpanel and wire a 240 Volt NEMA 14-30 outlet to it. I'll purchase a NEMA 14-30 adapter for my mobile connector from Tesla.

Before a contact an electrician I wanted to run this plan past this forum. Thanks for your input.

 

[nwdiver]

I've ordered a Model Y LR AWD.

I have a 100 Amp electrical service panel in my house basement. In my detached garage I have a 30 Amp subpanel that currently contains two 20 amp and one 15 amp circuit breakers for the lighting and outlets.

I'm thinking I could have an electrician install a 30 Amp breaker in the garage subpanel and wire a 240 Volt NEMA 14-30 outlet to it. I'll purchase a NEMA 14-30 adapter for my mobile connector from Tesla.

Before a contact an electrician I wanted to run this plan past this forum. Thanks for your input.

I guess your electrician will let you know for sure;

If not... IMHO even 16A @ 240v is plenty and that should hopefully be viable. That would be a NEMA 6-20.

 

[frankvb]

Up to the electrician indeed.

Considering the sub-panel is 30A total, and charging the car would be at 24A constant (80% of 30A) that would only leave 6A available for all the other circuits hooked up to it. Not sure if that's acceptable or not, if I had to guess I would say it's not ok.

 

[WhyYesPlease]

I don't have any expertise, but I have a similar situation to yours. The electrician who visited and is now preparing an estimate said when he was here that with my 40A sub-panel he could install a 14-50 (to draw only 40A though). When I asked about a garage door opener running at the same time, for example, he said that since they only run for ten seconds, should be no problem. Hope that helps.

 

[user212_nr]

I have a 100 Amp electrical service panel in my house basement. In my detached garage I have a 30 Amp subpanel that currently contains two 20 amp and one 15 amp circuit breakers for the lighting and outlets.

Your garage is wired with a lot of power. Is there some appliance that is powered by the 20A breakers? If so, then you have not enough power to charge a Tesla and use that appliance.

You can consider upgrading the wire that feeds the panel. It may not be very difficult to run a new wire where one already exists, and the panel is probably good for 100A.

 

[sewing1]

Your garage is wired with a lot of power. Is there some appliance that is powered by the 20A breakers? If so, then you have not enough power to charge a Tesla and use that appliance.

You can consider upgrading the wire that feeds the panel. It may not be very difficult to run a new wire where one already exists, and the panel is probably good for 100A.

No, there are no appliances in my garage. Just four 100 watt light bulbs and 2 garage door openers on the 15 amp circuit, and lots of outlets with nothing plugged into them on the two 20 amp circuits.

 

[Pilot1226]

This seems like a bad idea. If you have a subpanel with 30A devoted to it, and you're going to put that onto a 14-30 outlet, this seems like an overload scenario.

It might make more sense to try to replace the 30A subpanel with a 50A subpanel, which would give you at least an extra 20A.

I'd personally change the light bulbs to LED's immediately, to free up that much... (400 watts @ 120V is like 1/4 of your 15A circuit)

The garage door openers could be an issue if activated while you're pulling 30A. I'd consider the 50A changeover I mentioned above, then you can designate a 6-20 for that. If you really wanted to be "ballsy" you could push a 14-30 and just make sure you didn't use the garage door openers simultaneously and have something in the outlet.

The problem will be that with a 6-20 you're essentially "reserving" 16A of the 30A subpanel for the car charging. That only leaves you with 14A.

 

[nwdiver]

(400 watts @ 120V is like 1/4 of your 15A circuit)

I would hope that '400 watts' of light is only using 40w of electricity. If not ~$40 would fix that...

 

[paulk]

an electrician can use a clamp meter to see how much power your garage door openers are actually using, and you can replace your light bulbs with LEDs. if your openers only use a few amps each, a 24 amp draw from your car isnt bad.

you could also set the car to always draw just 15-20 amps, and then on that one day you need to charge faster, make sure to not use the opener until unplugging the car.