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I got a new home a few months ago and I'm planning to install a 240v outlet to charge my Tesla and just notice that there are only single pole circuit breakers in the electrical panel. I thought at least the one for water heater and dryer should be double pole breakers because they are 240v.

All the breakers in the panel, showing they are single pole, 20a breakers

breaker labeling indicating their use

Even if I turn off the breaker that marked as Dryer, it was still able to run. The other breakers work as expected.

Is there anything wrong with this setup? I am based in Texas if it matters.

Update: I found another panel by the electric meter, and it has double pole breaker for the dryer. The single pole breaker which is labled Dryer is for 120V outlet if I want to use gas dryer which makes sense now. The bad thing is I only have 1 slot left in the panel. Is it possible to add 240V outlet? Thanks!

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    Do you have all gas appliances, including your dryer? If so, then it would be standard to have just a 120v breaker for the electronics. But the dryer still working when you trip the breaker DEFINITELY means something is amiss, though it could be as simple as someone plugging the dryer into a different outlet than intended. Also, you're in TX, where is your A/c on your panel?
    – user278411
    Jun 29, 2022 at 8:51
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    Might have another panel somewhere, but if the dryer and water heater are 240, someone might have made a mistake. Try turning off both breakers, dryer and heater, but if it turns off you have a problem.
    – crip659
    Jun 29, 2022 at 9:52
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    Can you post photos of the nameplate labels for your dryer and water heater please? Jun 29, 2022 at 11:26
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    You probably have some double pole breakers out by your electric meter.
    – JACK
    Jun 29, 2022 at 11:54
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    @jay613, most new gas installations require 120v for the igniter circuit , standing pilot lights are not energy efficient.
    – Ed Beal
    Jun 29, 2022 at 21:03

1 Answer 1

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Analogy: If you need to pay a bill (in ye olden days of paper checks), you need to have a blank check in your checkbook and you need to have money in your account.

There are two different issues that come into play when adding a new big circuit such as an EV charger.

Space

This is the problem you already know about. There might be a relatively inexpensive solution, but we need more information to figure that out. Specifically, many panels have half-size/double-stuff/tandem breakers available. These put two ordinary breakers (typically 15A or 20A each) in the space of one. However:

  • The panel must allow for them generally
  • The panel must allow for them in the places you want to put them (some say only top, only bottom, etc.; some have a maximum limit)
  • They are not available with AFCI or GFCI

In your case, that means the only spaces possible for doubling up are 1, 3 and 5. All the others have TEST buttons, which indicates AFCI and/or GFCI and not available in half-size breakers. However, if you replaced 3 and 5 with a half-size pair in 5 and move 1 to 23, you would have 1 and 3 available for a 240V double breaker.

Load

The utility only provides a certain amount of power - e.g., 200A service. Each panel will have limitations as well. You can have breakers that add up to far more than your total service (you currently have 240A on one leg and 220A on the other, very likely more than the feed to this panel) because most breakers, most of the time, use far less than their rated capacity. In fact, the circuits that run for long periods of time (e.g., water heater, air conditioner, EV charger) are derated - e.g., a continuously running appliance that actually uses 40A will be on a 50A breaker.

The way to figure out what your utility service and your panel can truly handle is a load calculation. This takes into account various things, including the various typical large loads (water heater, dryer, oven, etc.), typical usage in kitchens and bathrooms, an amount per square foot to cover general usage (receptacles and lighting) and any specific extra loads such as EV charging.

In general, adding any big load should trigger a load calculation. In reality, most of the time things get added incrementally and it doesn't happen. But with a nearly full panel and a potentially huge extra load, a load calculation is essential before proceeding.

If the load calculation indicates that your service will be overloaded by adding the EV charger, you need to talk to your utility to find out about what options are available to increase your service.

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    I see two 120V circuits to garage, Code only calls for one (and the reason for the dedicated garage receptacle circuit is precisely for charging EVs). I see "hall", "entry" and "utility" breakers that may be redundant. I also see a separate 120V washer and dryer circuit, which may not be required (depending on the nameplates of the appliances). Jun 29, 2022 at 19:17

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