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Discussion Starter #1
I'm curious how an electrician would wire a new 240v outlet for L2 charging in my garage.

The garage is attached to the house. The house has a basement (where the electric service is) but there is no basement under the garage. There is a 240v outlet in the laundry room (with a dryer plugged in) which is just adjacent to the garage, but on the opposite side of a 2-car garage from where I would like the outlet.

Presumably they couldn't use that outlet's existing cable for car charging, assuming that I would ever want to charge and run the dryer at the same time. (It's a 30a breaker and dryers use about 25a.)

So that means they would have to run a new 240v cable to the circuit breaker box in the basement. I have 200A service. How would they do that, given they would have to come up from the basement in the garage (probably not a problem) but then somehow get it to the location I want on the opposite side of the garage?

In the basement, it's about 34 feet from the breaker box to the wall adjacent to the garage. The garage itself is 23 feet wide and the place I want the outlet is on the opposite side from the adjacent wall.

(Alternatively, there is an existing 240v outlet in the basement for a dryer (which is not used) that's only 6' from that adjacent wall, but there's only one breaker in the box labelled "Dryer" so I suspect that the circuit we use for the dryer and this outlet are on the same circuit, so we couldn't really use that either.)

In the garage, would they have the new cable go visibly across the garage ceiling and down the wall on the other side? Or would they somehow string it through the walls (which would be a longer trip.)

Finally, there's only one (single width) blank in the breaker box. Does that mean they'd have to install a new sub-panel?

Any guesses as to what a job like this would cost? Feels expensive to me.

Thanks for any advice.
 

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You need to get someone over to give you a price, preferably a few. The dryer circuit won't be enough for an EVSE to charge a Bolt or a 2019 Volt at the maximum rate. For a 50 amp breaker you'll have to run a separate circuit and a 240 volt breaker can be installed either by removing the spare basement circuit in the basement or by getting a breaker that supports two breakers in a single slot thereby freeing up two open spots.
As far as getting the wire over there, there is no way for us to tell without seeing the layout of your home. If you had to go across the ceiling that certainly doable, through the walls is doable too but a bit more work and cost especially if the walls are drywalled. Is the basement of the house under the spot where you want the charger? Run the wire through the basement and come up where the EVSE will be?

You really need to get someone over there to look at it.
 

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You have a challenging installation, why not consult a licensed electrician. They will know the applicable codes in your area, can recommend various options. Depending on the local codes this might require the wires for the 240V circuit to be buried, run in conduit.

Here is an article that explains a lot about tandem, aka cheater, circuit breakers, what they do and where they can be used: http://www.startribune.com/how-to-know-when-tandem-circuit-breakers-can-be-used-aka-cheater-breakers/140688183/

If you have an existing 15 amp or 20 amp circuit running to the garage it may be able to be converted to 240V (it would still be limited to the existing maximum amperage for the circuit).
 

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Discussion Starter #4
You need to get someone over to give you a price, preferably a few. The dryer circuit won't be enough for an EVSE to charge a Bolt or a 2019 Volt at the maximum rate.
I knew that would be the ultimate answer -- I was just looking to understand what I'd be in for. Presumably since a 2018 Volt draws half as much, it could be charged with a 30a circuit.

As far as getting the wire over there, there is no way for us to tell without seeing the layout of your home. If you had to go across the ceiling that certainly doable, through the walls is doable too but a bit more work and cost especially if the walls are drywalled. is the basement of the house under the spot where you want the charger?
Sadly the walls in the garage are drywalled and the basement is not under the garage and is on the opposite side of the garage from where I want the outlet.
You really need to get someone over there to look at it.
Yup.

How do they run cable through existing drywalled walls? Cut holes in the drywall at every stud to drill holes through the stud?
 

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Explore your options but before you make any decision on a 240V circuit you should determine your home charging needs.

How many miles per day do you typically drive (Monday - Friday)?

How many miles do you drive on the weekends?

Here is an estimate of how many miles of EV range you would obtain per hour of charging for different Level 2 (240V circuits) and EVSE:

20 amp circuit (limited by the electrical code to a maximum continuous load that is no more than 80% of circuit rating, for a maximum of 16 amps continuous (3.8kW) ~ 12 miles EV range per hour
30 amp circuit (24 amps continuous (5.8kW) ~ 18 miles EV range per hour
40 amp circuit (32 amps continuous (7.7kW) ~ 24 miles EV range per hour
50 amp circuit (40 amps continuous (9.6kW) ~ 29 miles EV range per hour

These numbers are approximate, would not change appreciably whether you were charging a Volt, Bolt or a Tesla.

If you are running a new circuit and have the panel capacity for a 50 amp circuit it makes sense, only costs a bit more to install the larger gauge wires for a 50 amp circuit.
 

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If you have a dedicated 20 amp 120V outlet in the garage this can be easily converted to a 240V NEMA 6-20, and would be the cheapest way to go. The post above from jcanoe is excellent in determining if this will meet your needs. For me, this is all I need at home regardless of what EV I get down the road.

When running new wiring the sky is the limit and is highly dependent on the situation. Bring in a licensed electrician for a quote.
 

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You have a challenging installation, why not consult a licensed electrician.
Always the best answer.

Mine was the same sort of challenge as the OP. The wires were routed through existing EMT (conduit for the layman) out to an existing junction box in the garage, and then extended to a new junction box below that. It was pretty challenging but it was doable.
 

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How do they run cable through existing drywalled walls? Cut holes in the drywall at every stud to drill holes through the stud?
Unfortunately, most homes in the U.S. are built that way. My home is reinforced concrete, built in 1976, but the electrical service runs through EMT (Electrical Metallic Tubing) placed inside the wall molds before the concrete was poured. The EMT allows upgrading and/or replacing existing wiring by pulling the old wires out and pulling new wires in. The EMT is also grounded to the main panel so just the live and neutral wires are needed. In my case, I rewired the external water heater circuit in my carport to a new 40 A breaker and placed apart from the main panel, then replaced the old tank heater for an efficient in-line heater. My JuiceBox EVSE (built from a kit - search my past posting in 2015) will use the same circuit (unplugging the heater and plugging the EVSE) and is setup for 30 A or 7.2 kW, and this was years before GM announced any EV using that charge rating. The EMt allows me to rewire for 80 A (which my EVSE can handle up to 16 kW) if I get a better EV. After Hurricane Maria, I was without power for over a month, so we are accustomed to cold showers at night, we do not need the heater all the time, and may leave that circuit to charge the EV instead.

And, as a similar advantage of using EMT, my home service (presently at 100 A) can be upgraded to 200 A if I want to install a DC charger system. The utility transformer is across the street (we have underground service), less than 50 feet from my main breaker and utility meter. A few hundred dollars of material and labor will do that job!

When I do get my first EV, I will charge it while parked, and plug the water heater for bathing only when I need it.
 

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My 240v cost a lot, but topping off during the day has been worth the price for those of us that don't want ICE use, if avoidable. Get multiple bids and go for it.
 

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My 240v cost a lot, but topping off during the day has been worth the price for those of us that don't want ICE use, if avoidable. Get multiple bids and go for it.
One tax incentive that didn't slam the resale value of my car:

30% Federal Tax Credit for Purchase & Installation of CC EVSE

I got back over $400. My install wasn't inexpensive either but this helped. It applied to the whole deal including the plugin EVSE. Well, that's how I put it on the tax form. The CPAs can argue that if they like - mine didn't.
 

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The federal tax credit you received when you purchased your EVSE has expired.
Ooops! I looked at the post date and it said 2018. Maybe there will be another retroactive extension at the beginning next year.

updated February 15, 2018

EVSE Federal Tax Credit
Alert: this Tax Credit was recently retroactively extended for 2017!
 

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Before you spend maybe more than you want on 240V, consider charging at 120V, or at least giving it a try for a little while. Lots of Volt owners use that and are happy with it (depends on your use case). Overnight is a long time for charging and it happens at the end of each day. Also, the range extender is always there to bail you out.

When I first got my Volt I thought I would be installing 240 V. My panel is in my garage in the most convenient spot, so easy. But I soon realized I didn't need it. In fact, I almost always charge at 8 amps at home. I just don't need the speed there. Over the past 3 years, having 240 V charging at home would have probably saved me 2-3 gallons of gas at most in all that time. And I usually use between one and two full charges on a typical day (I charge at work, too).
 

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The tandem / cheater breakers are two breakers on one 120 leg. Using a tandem in the one remaining box space will not provide the 240 desired.

Can a 12-4 cable be pulled through the wall by by tying it to, and then pulling out, the 12-3 that goes to the garage? That will provide you with two "hot" leads, one for a leg of "+"120, the other for the other leg of "-"120, and the neutral and ground.

120 charging is less efficient than 240 charging. There is less electricity bought from the power Co. to re-fill what the car used when 240 is used. 120 requires buying about 12.5 kWh to put back the 10 the car used, 240 requires about 12 to refill that same 10 used.
The amount of time from my off-peak start until I leave for work at 0dark:30 wasn't enough to get a full charge even at 12 amps of 120.
Those are the reasons that prompted me to have 240.

<edit> I just re-read the first post. My suggestion would work for you ONLY if
There is an existing 120 outlet on that far wall and
That outlet is wired directly to the breaker box, and not as a segment added to another outlet box. <end>
 

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I ran a 60 amp 240V circuit breaker from my main box (200 amp service) to a subpanel in the garage. I was doing a renovation so had the carpet ripped up and cut a new hole in the floor for a floor heater I had to move because of a sliding glass door that was installed. Cut a hole in drywall to feed the wire from main panel down through to the floor. From there down to the finished garage and ran it along main support beam to outside wall where the subpanel was mounted. Once the subpanel was mounted, I ran four 15amp lines back into the house, one dedicated to freezer, one dedicated to electric fireplace. One for extra wall outlets for computer corner and TV room and one to run a ceiling fan in utility room and electricity to propane fireplace upstairs. 30 amp 240V for wall oven (powder coating and curing VHT paint), 20 amp 240V for air compressor (later shared with ECSE L2), 20 amp 120 Volt for welder/misc. Didn't cost a lot of money. Takes some planning, can't get specific without seeing how your house is built.

To keep it legal and your fire insurance intact you need an electrical permit ($139) which includes an inspection before cover up and final inspection. Had access to electrical inspectors at the time as I planned to do things not covered in code book and needed their input. Passed both inspections. It was a fairly complex installation for residential. Yours would be simpler.

You would need a double width breaker to pick off 240V from your main panel so you might need a larger main panel to give you that unless the breakers could be rearranged some how. If that's the case you'd need an electrician because you are playing with the main power coming into the house that would have to be turned off before proceeding with main panel substitution. Don't know why they would have two dryer outlets on one circuit. Usually only one per circuit. I assume you have electric heat. If you had gas you could have a gas dryer freeing up the 240V line for the garage.
 

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Discussion Starter #17
Thanks, everyone, for all the great suggestions. There is a 120v outlet near where I want the charger, but I would presume that it was not a dedicated circuit -- probably daisy chained from other outlets in the garage. Clearly this is going to be more complicated than I expected (and likely more expensive). I may take one poster's suggestion and just use 110v at first. Thanks.
 

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Thanks, everyone, for all the great suggestions. There is a 120v outlet near where I want the charger, but I would presume that it was not a dedicated circuit -- probably daisy chained from other outlets in the garage. Clearly this is going to be more complicated than I expected (and likely more expensive). I may take one poster's suggestion and just use 110v at first. Thanks.
I would say that it doesn't have to be a "dedicated" circuit. However, it should be "lightly utilized" and as long as all connections are of good practice you should be good to go. The circuit I use (12 gauge wiring) has some lighting (now LED) and the garage door opener on it and I have had no issues in the past 7+ years.

VIN # B0985
 

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I would say that it doesn't have to be a "dedicated" circuit. However, it should be "lightly utilized" and as long as all connections are of good practice you should be good to go. The circuit I use (12 gauge wiring) has some lighting (now LED) and the garage door opener on it and I have had no issues in the past 7+ years.

VIN # B0985
It needs to be a dedicated circuit to be able to convert a 120V circuit to a 240V circuit, can be 15 amp circuit if that is all that the current wiring will support. ClipperCreek even sells a Level 2 EVSE (hard wired only) rated for use on 15 amp circuits for this purpose. Changing the circuit to 240V will increase the output of the EVSE from 120V @ 12 amps (1440W) to 240V @ 12 amps (2880W) and reduce the time needed to charge by half.
 

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It needs to be a dedicated circuit to be able to convert a 120V circuit to a 240V circuit, can be 15 amp circuit if that is all that the current wiring will support. ClipperCreek even sells a Level 2 EVSE (hard wired only) rated for use on 15 amp circuits for this purpose. Changing the circuit to 240V will increase the output of the EVSE from 120V @ 12 amps (1440W) to 240V @ 12 amps (2880W) and reduce the time needed to charge by half.
My reply was addressing his statement that he might try "110v" at first. If he is going to step up to 240v my recommendation would be to forget using existing wiring, and go with a new dedicated line with future-proofing to at least 40 amps.

VIN # B0985
 
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