Using dryer outlet to power outdoor EVSE?

[TigerNinety]

Hello all,

I apologize if I'm asking an ignorant question, but my scan of topics on this thread so far doesn't seem to answer this directly.

I hope to have my CPO Tesla Model S in August. I want to do better than "trickle charge", but I don't have a dryer outlet (spare or otherwise) in a garage. I'm imagining that I'll opt for one of BSA's DryerBuddy Plus AUTO boxes of one form or another to share the 30Amp dryer outlet in my basement nearest the wall of the house next to the driveway.

My question is: what should I expect to have on the outside of the house, if I have the DryerBuddy on the inside? I know BSA will do a range of customizations, but will I need to have something like a JuiceBox on the outside? I realize that if the dryer outlet and the car were closer together (and not on opposite sides of a wall) this would be pretty straightforward. But once I need to get wire through a wall (with the help of our electrician), what needs to go outside, in the driveway?

Thanks,

Todd

 

[Rocky_H]

My question is: what should I expect to have on the outside of the house, if I have the DryerBuddy on the inside? I know BSA will do a range of customizations, but will I need to have something like a JuiceBox on the outside? I realize that if the dryer outlet and the car were closer together (and not on opposite sides of a wall) this would be pretty straightforward. But once I need to get wire through a wall (with the help of our electrician), what needs to go outside, in the driveway?

Tesla cars come with a charging cable. It can have many different swappable plug adapters. One of which goes to electric dryer outlets. So you would just buy the dryer adapter from Tesla's website that matches your dryer outlet and plug in with that. You don't need a Juicebox or any other 3rd party thing.

There are two types of dryer outlets, though, so check which kind you have. The 10-30 was the older kind, and about 1996, code stopped allowing those, and the 14-30 is the newer kind. Here's a chart where you can identify which yours is.
NEMA connector - Wikipedia

 

[TMeister]

Unless you really really need the capability of the dryer buddy to auto switch the loads you can just daisy chain another 240V outlet from the existing dryer outlet to wherever you need it to go for your EVSE. If it is a 30A outlet, then that's just 10 gauge Romex (check your local codes) to your EV outlet.

Then you have the car only charge at night when you know you won't be using the dryer. In the rare circumstance that you need to do a load of clothes while charging, just interrupt the charge as needed. Also, remember that you have to de-rate the load to 80% for a continuous load such as an EV. That is, for a 30A circuit, you only charge at 24A.

You will still need an EVSE (Electric Vehicle Service Equipment) unit to direct wire or plug into your outlet. You can use the UMC that should come with the car until you figure out what EVSE you like.

 

[Rocky_H]

Also, remember that you have to de-rate the load to 80% for a continuous load such as an EV. That is, for a 30A circuit, you only charge at 24A.

People use the proper plug adapter so the car does this for them. No one should have to "remember" to do anything.

You will still need an EVSE (Electric Vehicle Service Equipment) unit to direct wire or plug into your outlet. You can use the UMC that should come with the car until you figure out what EVSE you like.

Disagree. I don't get why people seem to think that they need to buy a different charging device. The charge cable that comes with the car IS an EVSE, and you can use it permanently. No need to get something else if you don't want to. My UMC is still my permanent charging hanging in my garage 6 years later.

 

[TMeister]

People use the proper plug adapter so the car does this for them. No one should have to "remember" to do anything.

There are cases where an EVSE is programmable, like mine and can be set to whatever delivery current one wishes. That was the only caution stated. The case where the EVSE does this derating is in the use of the UMC and its corresponding plug. The car doesn't do this. The UMC presents the max current on the pilot line to the car as a PWM signal.

Disagree. I don't get why people seem to think that they need to buy a different charging device. The charge cable that comes with the car IS an EVSE, and you can use it permanently. No need to get something else if you don't want to. My UMC is still my permanent charging hanging in my garage 6 years later.

Yes the UMC is an EVSE and my comment was that the user can decide whatever EVSE they want to use long term. I didn't exclude the UMC in that list. They may like it just as well as any other EVSE. So can I disagree to your disagree and that makes it an agree?

 

[dark cloud]

My UMC is still my permanent charging hanging in my garage 6 years later.

Same as my setup. Like @TigerNinety when investigating my options I thought I would need a dryer buddy or a wallcharger but the Nema14/30 I installed in the garage serves my purposes just fine, and it cost me hundreds less than the "sexier" Elon musk singed wall connector setup. I charge at 24 amps/242 volts which yields almost 6kW; enough to easily fully charge the 85 kW (actually 75ish) car overnight.

I would first investigate (have your electrician investigate) whether you have space in your panel for a double 30 amp breaker, do a load calculation for capacity, and if you can get some 10 gauge directly to the panel, and save yourself even buying the dryer buddy. If you can fit the 50 amp and want 40 amps then it would be ever faster; need fatter more expensive Romex though.

Here is an excellent resource: Home Charging Wiring Guide | TeslaTap

To answer your question though, what goes outside, if it is exposed to the elements you would need an outdoor rated receptacle such as this: https://www.amazon.ca/Talon-LGP1S-Enclosed-Outdoor-Receptacle/dp/B00M3H6494. if you do use the dryer buddy you need to see how long of a cord you need, and what plug is rated for outdoors; the guy can customize it to do anything you want if I recall.

 

[JPoldo]

Since there will be frequent plugging and unplugging, make sure outdoor receptacle can handle the insertions. Your dryer circuit breaker probably isnt a GFCI, so change it to GFCI.

 

[ucmndd]

Unless you really really need the capability of the dryer buddy to auto switch the loads you can just daisy chain another 240V outlet from the existing dryer outlet to wherever you need it to go for your EVSE. If it is a 30A outlet, then that's just 10 gauge Romex (check your local codes) to your EV outlet.
.

This is very much not permissible by code. You can’t “daisy chain” 240v outlets on the same circuit.

 

[TMeister]

This is very much not permissible by code. You can’t “daisy chain” 240v outlets on the same circuit.

Well... this is a common misunderstanding. The 2020 Edition of NFPA 70 (the National Electrical Code Book) in its branch section, 210 specifically talks about branch circuits under 277 V with 120V to neutral as just fine to have multiple outlets. Branch circuits up to 50 amps are permissible. Perhaps I should have said to wire the two outlets correctly to code but there is no code section (do you have a reference?) that I could find that says only one outlet on a 240V circuit. Maybe in your jurisdiction, a local rule is in place?

The reason one doesn't see many multiple outlets on 240V branch circuits is that in the US these are mostly for high power devices such as your oven, dryer, cooktop, etc which if any two are on would trip the breaker. But that is the point of the OP's request. They know that running a dryer load and having the car plugged in will trip the breaker. The dryer buddy fixes that, but nothing in the code says that you can't have multiple loads on a 240V circuit that in total will trip the breaker.

 

[JPoldo]

This is very much not permissible by code. You can’t “daisy chain” 240v outlets on the same circuit.

I believe ucmndd is correct on code, but not sure why it is a safety hazard. The circuit breaker will trip if load exceeds wire capacity. NEC probably demands a small sub-panel at the dryer with separate breakers to dryer and GFCI to outdoor waterproof Tesla receptacle. Electrical inspector will look for this equipment. However, if it was my house with no inspection, this EE would consider daisy chaining loads on the same 30A GFCI.

 

[Rocky_H]

There are cases where an EVSE is programmable, like mine and can be set to whatever delivery current one wishes. That was the only caution stated. The case where the EVSE does this derating is in the use of the UMC and its corresponding plug. The car doesn't do this. The UMC presents the max current on the pilot line to the car as a PWM signal.

Yes, still irrelevant. The user does not need to "remember" to dial anything to any current value. As you pointed out, these are functions built into the EVSE. It signals what the proper allowed maximum amps are, and the car can safely use up to that amount. Unless there is something very weird I'm not getting about your programmable EVSE, where you can do something unsafe, like plug it into a 20A circuit and set it to announce that you can pull 40A or something. I haven't seen a device like that.

This is very much not permissible by code. You can’t “daisy chain” 240v outlets on the same circuit.

Well... this is a common misunderstanding. The 2020 Edition of NFPA 70 (the National Electrical Code Book) in its branch section, 210 specifically talks about branch circuits under 277 V with 120V to neutral as just fine to have multiple outlets. Branch circuits up to 50 amps are permissible.

There is a lack of specificity that is causing you all to talk past each other. For general purposes, sure, the 210 section still talks about multiple outlets on those circuits. But the section 625 is all about electric vehicle charging, and it goes completely hardline that any outlet installed for the purpose of electric vehicle charging, MUST be the only outlet on that circuit. Period.

 

[TMeister]

Yes, still irrelevant. The user does not need to "remember" to dial anything to any current value. As you pointed out, these are functions built into the EVSE. It signals what the proper allowed maximum amps are, and the car can safely use up to that amount. Unless there is something very weird I'm not getting about your programmable EVSE, where you can do something unsafe, like plug it into a 20A circuit and set it to announce that you can pull 40A or something. I haven't seen a device like that.

Yeah, my OpenEVSE allows me to pick any output value I want. So I could do as you say and cause an issue. One has to match the power available in the branch circuit with the output value.

There is a lack of specificity that is causing you all to talk past each other. For general purposes, sure, the 210 section still talks about multiple outlets on those circuits. But the section 625 is all about electric vehicle charging, and it goes completely hardline that any outlet installed for the purpose of electric vehicle charging, MUST be the only outlet on that circuit. Period.

That's an interesting section. I wonder how multiple HPWC sharing a circuit are OK then? Probably because there are no outlets. The code writers focused on outlets being the limit of one. So for the OP, would they still be OK if they had a dryer outlet and a hardwired EVSE? That doesn't seem to be covered on my first reading of the code. For the two outlet case not good. And I think the code would prohibit a dryer buddy if one of the downstream circuits was intended for an EVSE since two outlets are not allowed on an EVSE branch circuit.

 

[BSAElectronics]

Hello all,

I apologize if I'm asking an ignorant question, but my scan of topics on this thread so far doesn't seem to answer this directly.

I hope to have my CPO Tesla Model S in August. I want to do better than "trickle charge", but I don't have a dryer outlet (spare or otherwise) in a garage. I'm imagining that I'll opt for one of BSA's DryerBuddy Plus AUTO boxes of one form or another to share the 30Amp dryer outlet in my basement nearest the wall of the house next to the driveway.

My question is: what should I expect to have on the outside of the house, if I have the DryerBuddy on the inside? I know BSA will do a range of customizations, but will I need to have something like a JuiceBox on the outside? I realize that if the dryer outlet and the car were closer together (and not on opposite sides of a wall) this would be pretty straightforward. But once I need to get wire through a wall (with the help of our electrician), what needs to go outside, in the driveway?

Thanks,

Todd

Hi Todd, did you find a solution for your charging? I would be happy to answer any questions you may have on my Dryer Buddy products and customization options.
Cheers
Brad A.