Temporary Charging Solution - 10-30 & Mobile Charger

[igotzzoom]

Rather than spending the $3,000+ to do the 200A panel upgrade, I think as an interim solution, we're going to put a new plug in the garage on the currently unused 30-amp dryer circuit (we have a gas dryer) and utilize the mobile charger with the 10-30 adapter. I plan on doing off-peak charging and get on a TOU plan. My only concern is during the hottest days of the summer when we're running AC at night and charging my car, if it'll trip any breakers. Any experience with a similar arrangement appreciated. We plan on doing the 200A panel at the same time we do solar.

 

[iluvmacs]

My only concern is during the hottest days of the summer when we're running AC at night and charging my car, if it'll trip any breakers.

If this winds up being a problem, you can always limit the charge rate of the car to be lower. But... I can tell you from my experience with a 100A service house previously, and our Leaf charging at 27A, we never had an issue in the summer (A/C, electric stove & dryer...)

 

[Eno Deb]

I charge from a 10-30 dryer outlet. I consider it a permanent solution. Plenty fast for my daily driving (~22 miles/hour), charging only during the night (EV TOU plan).

Regarding the panel capacity, you need to make an estimate based on your utility feed. What's the breaker ampacity for the A/C? Normally they're between 30 and 50A, so assuming a 100A feed it shouldn't be an issue.

 

[Rocky_H]

That should be totally fine. Since it was originally sized into the house's original electrical system, it should be able to work just fine without tripping anything.

 

[Gretta]

This is great news as I'm taking delivery this Sat! My house is currently on 100 amps as haven't upgraded (contractor during house reno included cost of uping to 200 amps and brought cables, but turns out he lied and never actually did it! I had to move out of house, and never realized this until last year : { ) to 200 amps yet, but ordered a 10-30 adapter to charge with my dryer outlet. Glad to hear that 100 amps is not going to be an issue. Thx all!

 

[rickdogg82]

50A breaker in 100A panel. Using NEMA 14-50 with the UMC. No issues. An electrician will tell you if you'll have any problems. You'll likely need a permit in MV.

 

[M3BlueGeorgia]

I charge from a 10-30 dryer outlet. I consider it a permanent solution. Plenty fast for my daily driving (~22 miles/hour), charging only during the night (EV TOU plan).

Regarding the panel capacity, you need to make an estimate based on your utility feed. What's the breaker ampacity for the A/C? Normally they're between 30 and 50A, so assuming a 100A feed it shouldn't be an issue.

One suggested change... Add a ground cable and switch to 14-30.

Note: Its what I've used for a year.

 

[Rottenapplr]

Rather than spending the $3,000+ to do the 200A panel upgrade, I think as an interim solution, we're going to put a new plug in the garage on the currently unused 30-amp dryer circuit (we have a gas dryer) and utilize the mobile charger with the 10-30 adapter. I plan on doing off-peak charging and get on a TOU plan. My only concern is during the hottest days of the summer when we're running AC at night and charging my car, if it'll trip any breakers. Any experience with a similar arrangement appreciated. We plan on doing the 200A panel at the same time we do solar.

Have you had an electrician see your panel and do a load calculation? To be 100% certain you won’t have issues with your electric needs.

I was initially quoted 2-3k for a 200amp panel. But when he saw my panel, ac, dryer, etc.... he calculated an additional 30amp was enough. So my panel is now 130amp. And he put a 40 amp breaker for my tesla 14-50 charger. I’ve run my dryer, central air, and tesla charging without issue. My max charge is 30-31 miles per hour using the mobile charger

 

[Eno Deb]

One suggested change... Add a ground cable and switch to 14-30.

Note: Its what I've used for a year.

Well, having to change the wiring kind of defeats the main reason why I'm using the 10-30 (simply using what was already there with no installation required). If I were to change the wiring, I might just as well switch to 14-50. Besides, the additional ground doesn't provide much benefit for EV charging since it's a pure 240V load, so neutral isn't being used anyway.

 

[DavidElg]

Considering you were able to use the dryer and A/C together without tripping the breaker, I imagine you'll be fine charging the car and using the A/C. I used my existing 30 amp dryer outlet for about the first 4 months of owning a Tesla and it was perfectly fine. I would not recommend plugging/unplugging the dryer and charging cable though as it will quickly wear out the outlet. I purchased a DryerBuddy, but I've also seen splitters on Amazon that work. You would just need to be very careful that no one in your home attempts to use the dryer while the car is charging.

 

[eprosenx]

Odds are you will be fine with that 30a circuit, but you never know if the house has already been overloaded. (perhaps when the AC was added someone already factored in that the dryer was gas even though they did not disable the old dryer receptacle)

I would also be concerned about the age of the main panel. 100a panels in single family residences have not been standard for a very long time.

It may be worth posting pictures of your existing panel here as folks may be able to give you a rough idea if you are way over on your load calculations and also be able to identify if you have an old panel that is a fire hazard.

 

[M3BlueGeorgia]

Well, having to change the wiring kind of defeats the main reason why I'm using the 10-30 (simply using what was already there with no installation required). If I were to change the wiring, I might just as well switch to 14-50. Besides, the additional ground doesn't provide much benefit for EV charging since it's a pure 240V load, so neutral isn't being used anyway.

Tesla apparently ignore the neutral anyway. But they use the ground.

There's a reason electrical codes were changed to switch from 10-30 to 14-30 in 1997.
I'm a big believer in having grounded electrical connections for electronic equipment.

Upgrading from 10-30 to 14-30 is a routine and relatively cheap electrical change, and (depending on jurisdiction) is probably required to sell the house. It generally doesn't require rewiring.

 

[eprosenx]

Tesla apparently ignore the neutral anyway. But they use the ground.

There's a reason electrical codes were changed to switch from 10-30 to 14-30 in 1997.
I'm a big believer in having grounded electrical connections for electronic equipment.

Upgrading from 10-30 to 14-30 is a routine and relatively cheap electrical change, and (depending on jurisdiction) is probably required to sell the house. It generally doesn't require rewiring.

Tesla uses the “neutral” wire on a 10-30 receptacle as the ground. So while using an actual dryer on a 10-30 is somewhat dangerous due to the lack of the ground, using a Tesla charger on it is not so bad.

Upgrading from a 10-30 to a 14-30 receptacle might be trivial or might be very difficult depending on if there is a ground wire already run in the walls. A 14-30 requires three current carrying (insulated) conductors plus a ground. A 10-30 only requires three insulated conductors and no ground.

 

[Eno Deb]

Tesla apparently ignore the neutral anyway. But they use the ground.

There's a reason electrical codes were changed to switch from 10-30 to 14-30 in 1997.

Yes, but the added safety is mainly for applicances that use both 120 and 240V. If there is no current on neutral like in an EVSE, the risk introduced by combining ground and neutral is low, especially if the circuit doesn't go to a subpanel.

Upgrading from 10-30 to 14-30 is a routine and relatively cheap electrical change, and (depending on jurisdiction) is probably required to sell the house. It generally doesn't require rewiring.

Actually it will usually require rewiring. Shared ground/neutral standards like the 10-30 were originally introduced to save on copper by dropping the fourth wire. In my (somewhat older) house there are only 3 wires going to the dryer outlet.