Hot Topics: Installing a Car Charging Outlet

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Original Post: Installing a 240V Outlet for Charging My Chevy Volt

mettam Member

I am not an electrician, and I need to put a 240V outlet in my car port, to plug in my 2016 Chevy Volt.

I will probably hire an electrician to put the breaker in, but I want to buy the components beforehand, and install the things I can install, like the outlet box.

I have a "Zinsco" main breaker panel I will be adding the new 240V breaker to.

So my preliminary questions are:

  1. If I list the components on my shopping list could someone advise if they are the correct components, for my Zinsco panel and for the car I am going to plug in (2016 Chevy Volt)?
  2. Is this the correct forum for this type of question?

Thanks in advance.

stickshift Group Moderator

Yes, this is the correct forum. That said, I would talk to the electrician first, as many of them are not fans of using items supplied by the homeowner.

ray2047 Group Moderator

Zinsco has been out of business for decades. Their panels are considered a fire hazard. You might find a breaker but it will cost you. Best to replace your breaker panel.

mettam Member

Yes, I have heard Zinsco made a notoriously bad breaker panel. Because I will not be living in this house much longer I don't want to invest too much in replacing it.

So my options are:

  1. Keep plugging into the 120V outlet and put up with having to pay a much higher rate per kwh.
  2. Install 240V breaker into the Zinsco panel.
  3. Or, (if this is possible) get a double adapter and keep the washing machine and the EV charger plugged into the same 240V outlet, then run a long cable from the laundry out into the carport.

Is option three feasible? If the washing machine and the EV are both drawing power at the same time will something break?

ray2047 Group Moderator

Do you mean dryer not washing machine?

"Keep plugging into the 120V outlet and put up with having to pay a much higher rate per kwh."

Never heard of a higher rate for 240V. 240V is what your house is supplied with and what the meter measures.

pcboss Forum Topic Moderator

A kwh is the same regardless of voltage. why do you think the rate is higher for 120 volts vs 240?

mettam Member

Ok, what I mean is I need to charge at a faster rate (240V) so that I can charge within low rate period (11pm-7am @ 9c/kwh) If I continue pulling at the 120V I would not be able to charge the car within that low rate period. Sorry I didn't make that clear.

Is it possible to plug two appliances into one 240V outlet. Dryer and EV?

ray2047 Group Moderator

Yes, if both are rated for 30 amps, but not at the same time. Best would be a switch to choose which receptacle was in use and hard-wire to the garage from there, assuming the garage is attached to the house. Extension cords are not recommended due to possible voltage drop. Extension cord would need to be at least #10 which would probably cost more than hard-wired.

mettam Member

"Yes, if both are rated for 30 amps, but not at the same time. Best would be a switch to choose which receptacle was in use and hard-wire to the garage from there."

Sorry I have some dumb questions.

  1. What do you mean if both are rated for 30 amps? Are you assuming the dryer is on a 240V at 30 amp breaker?
  2. What would a switch to choose which receptacle is being used look like? Would you be able to send me a link to such a switch so I could get an idea?

My carport isn't attached to the house. I live in a Town House and the carport is out front, there is a courtyard between the townhouse and the carport. I could run a 25ft #10 extension cord from the laundry to the carport.

ray2047 Group Moderator

"Are you assuming the dryer is on a 240V at 30 amp breaker?"

Yes, 30 amp is correct for most electric dryers.

"What would a switch to chose which receptacle is being used look like?"

One type is a single circuit transfer switch usually used to choose weather a furnace is powered from the line voltage or a generator. Actual wiring would be different than when used for the intended purpose.

"My carport isn't attached to the house."

Then you can't by code run a second circuit. You would need to abandon the existing 120 volts and install a subpanel.

"I could run a 25ft #10 extension cord from the laundry to the carport."

That may be the cheapest route. Just unplug the dryer each time you use the extension cord.

Mad Scientist Member

If you're planning to sell the house, you may as well replace the breaker panel. Any home inspector worth his salt will ding you for the Zinsco breaker panel, especially if you're charging your car off of it.

pcboss Forum Topic Moderator

The home inspector could mention the panel, but it would be a negotiated item between the buyer and seller if it were requested to be changed.

mettam Member

Thank you "Mad Scientist" and "pcboss" This is definitely something to consider.

I think I might forego the whole charging at 240V plan, and just keep charging through my 120V outlet.

I generally plugin at 8pm and leave at 8am and in this time my Chevy Volt's 18.4kwh battery is fully charged. The downside is I will only be able to charge eight hours at the cheap rate (11pm-7am), and four hours at the more expensive rate.

Hal_S Member

A 25' extension cord for 30 amp four prong cord is $120 from big-box-blue.

If you save enough on charging to be anywhere close to break-even, get it.

I would also get a plastic cord-roller. Get in the habit of unplugging from the wall, rolling up the cord, and tossing it in the trunk—that way you have the 25' cord with you if you find you need it.

skeeter_ca Member

That would mean you can't go to sleep unit 11pm. Or get up at 11 and plug it in. Or forget to get up and plug it in, then you have a low battery the next morning. Sounds like a big inconvenience to save maybe 75 cents.

joed Member

Put it on a timer. They make heavy duty ones. I had one for my block heater to turn it on at 5am to be ready for work.

electric_dummy Member

But you would't have to get a new Zinsco breaker. You already have a 30 amp Zinsco breaker protecting your electric clothes dryer.

So make it power a 30 amp subpanel instead (choose a modern brand subpanel). Then put two 30 amp breakers in the subpanel. One protects the dryer, the other protects the car charger receptacle.

This way if you accidentally use both receptacles at the same time, your subpanel "main" breaker or the 30 amp Zinsco will trip and protect your house from starting a fire. No transfer switch needed.

You can also put in a 120V convenience outlet from that subpanel.

Make sure you use the right wire type.

Just so you're aware, 30A requires #10 AWG copper wire. And ideally a car charger would have 50A, which requires #6 AWG copper wire. But you need to be sure you have the correct Zinco 50A breaker, which they don't make anymore (unless you want to replace your main panel with a different brand).

CasualJoe Member

"And ideally a car charger would have 50A, which requires #6 AWG copper wire. But you need to be sure you have the correct Zinco 50A breaker"

A new breaker isn't a problem, but I wouldn't invest in any Zinsco panel for myself or family.