I think you should try to do this as a dryer outlet—NEMA 14-30—and get some quotes on that. That’s still pretty solid for overnight charging. Since it will be used almost exclusively at night, you can keep it from overlapping with the use of your real clothes dryer, and oven, etc. and then it can probably be installed on your existing main electrical service. Tesla doesn’t sell a direct 14-30 adapter anymore, but you can get a 10-30 adapter from them, and get a short conversion cable from a 10-30 outlet to 14-30 plug.
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I'm just pointing out current code. I'm presuming the OP want to get it permitted and inspected and the inspector will look at the load calcs. They may not double check everything especially if it's a local contractor that they know and trust but it's still required.
Service & panel upgrades generally start at $2,500 in territories where PoCo pays for meter equipment and transformer-to-meter run, goes up from there. If you do need to upgrade your service and panel, then for what you describe that's about right. Conduit and wire to the garage @ 100-150 ft. is going to be fairly pricy (see the reference to the other thread for cost on a per-ft basis).
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To add to sorka's point: Some jurisdictions look very carefully at the load calculations and make it part of the permit application; others assume the electrician has done it properly and don't really call it into question. 3 VA / sq ft includes both lighting and general purpose loads, regardless of CFL or LED usage, and as sorka noted it's Code that has to be followed because it's codified as law (violating it can mean misdemeanor charges in some jurisdictions).
I concur with those saying that you should ask electricians for alternatives. Installing a Wall Connector can be done at many different current settings. Ask the electrician what load you could sustain on your existing service and go with it.
This clause would seem to cover an EV charger, assuming you were smart enough to schedule your charging when you weren't cooking or drying clothes, etc.
"Noncoincident loadsWhen two loads are not likely to be energized at the same time, 220.60 allows us to use only the largest load for the calculation of the service. This is typically applied to dwelling units with both electric heating and air conditioning, since they are not expected to run at the same time."
MrJones390
Space Boat
You might as well buy solar panels and have the installers throw in EV charger for free. That's what I did to save the $4k.
Correct. If you can offset another large load (e.g., an electric dryer), you can use this section. Some AHJ's frown upon it and will challenge the application of it, but most will trust that the electrician has done his work in asking about the loads. Typically, AHJ's will not permit you to offset general-purpose & lighting loads or required receptacle (e.g., kitchen SABC) loads, and they'll look for offsetting loads like dryers or cooking appliances.
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There's only one issue with this if you have a service that's less than 200A already, and that's bus capacity on your service panel if the solar installation is backfed through a breaker. You may not exceed 120% of the service panel's bus capacity when considering the main breaker / main lug feeder plus all backfeed breakers. If you have a 100A panel with 100A main, this means you can't install more than a 20A breaker to back-feed solar PV systems. PV systems are generally considered continuous for the purposes of sizing, so your backfeed circuit size must be AC rating of inverter x 125%. This means that you'd be limited to a 3.8 kW inverter on a 100A service panel. 3.8 kW isn't going to give you much of a charging rate for your car.
If you have a 200A service already, it's typically not an issue; but a smaller panel is.
You have other options - for example, if your solar PV system is interconnected on the line side of the service you can size it larger, but in some cases/jurisdictions that means other special requirements and generally invalidates you for things like expedited permit processes.
When I upgraded my electrical service from screw in fuses to a 220 service, added circuit breakers, 220v outlet in garage for the dryer and grounded plugs throughout the house it cost me about $5k, it sounds like the bulk of the cost is upgrading your service. Adding a 50 amp Nema 14-50 outlet cost me only $200, but I already had a 200 amp service.
SER, no. USE, yes.
However, USE can't be used for interior wiring and must terminate outside the building in an enclosure that provides protection for the cable.
Zenon
Member
Definitely get a second or third opinion. I had bought all the parts needed to do the job my self for $40, and had an electrician come out to let me know if my house would be able to use the Tesla wall connector at 80 amps. While he was there I told him (which is true) that I was going to install the NEMA 14-50 myself as a temporary option until I get my wall charger. He was very nice and preceded to tell me what I need to do and what I should avoid. At that point I took out $80 and said if you want to do it for that amount you can go ahead. He agreed and did the job. The whole thing cost me only $120 but my house has a 200 amp breaker box. The point is that if you look around you will get a lot better deals or options.
There are a lot of variables to consider. My house has 100A feed, so you don't have to have more than 100, but you also need to understand what you're running and when. We have a gas heater and an electric oven, but I wouldn't run all the other things while the car is charging. We only charge at night. We had a long conduit run from the back of the house to the garage in order to get the circuit there. So our install was about $1200. So it's not out of the ordinary, but you may be able to avoid upgrading your panel if you don't have a lot of electrical load or don't run them at the same time.
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