What am I limited to for EV charging on this sub panel?

[JeffKeryk]

If you had a 60 amp circuit would it draw more or is that all it will do?

The RWD cars are single motor and smaller battery. The onboard charger pulls 32A max. The dual motor cars can pull more amperage. Superchargers can supply much more, as they bypass the onboard charger and use their own.
32A is the sweet spot because it is easier on the batteries.

 

[pantygnome]

If you had a 60 amp circuit would it draw more or is that all it will do?

My sister has a Model S and I was under the impression that it somehow auto negotiates the charge amperage. My brother in law had my dad install a dedicated 50A circuit if they wanted to charge at home.

 

[RhondaHonda]

The RWD cars are single motor and smaller battery. The onboard charger pulls 32A max. The dual motor cars can pull more amperage. Superchargers can supply much more, as they bypass the onboard charger and use their own.
32A is the sweet spot because it is easier on the batteries.

Do you have the Wall Connector installed at home for home charging? Can I just plug whatever comes with the car directly into a 30 or 50 amp outlet without the Wall Connector? I’m still learning but contemplating a Y or 3, both of the Performance variety.

 

[brianl703]

It looks like the input wires are only 6 AWG. Is the input cable exposed somewhere you can see the size printed on the outside.

Also looks like it's aluminum, unless it's common practice to include an aluminum ground wire with SER cable that otherwise has copper conductors.

 

[ecotourist]

If you had a 60 amp circuit would it draw more or is that all it will do?

My Tesla Model 3 SR+ will only draw 32 Amps on 240 Volts. You could set it to draw less less, but that's the maximum.

Other Tesla models may draw more.

I believe the rule for continuous current is 80% of the maximum rating, and since 80% of 40 is 32, a 40 Amps or higher circuit meets the requirement. So a 60 Amp circuit would provide 32 Amps easily.

 

[ecotourist]

Do you have the Wall Connector installed at home for home charging? Can I just plug whatever comes with the car directly into a 30 or 50 amp outlet without the Wall Connector? I’m still learning but contemplating a Y or 3, both of the Performance variety.

I had a 240 Volt 40 Amp outlet similar to an electric stove outlet (a NEMA 14-50 outlet) installed at a convenient location in my garage. You buy a simple adapter from Tesla that plugs into the NEMA 14-50 outlet which connects to the Tesla charge cord - supplied with my car but now an extra cost item.

Having a NEMA 14-50 outlet installed by an electrician cost us $500 for parts and labour. The adapter was about $50. You can find a variety of adapters on the Tesla website but that is the only one I've needed in almost 2 years of service.

The idea is to get that stuff organized in advance so you're ready to charge at home from day 1. You don't want to have to immediately go looking for a Supercharger.

 

[JeffKeryk]

Do you have the Wall Connector installed at home for home charging? Can I just plug whatever comes with the car directly into a 30 or 50 amp outlet without the Wall Connector? I’m still learning but contemplating a Y or 3, both of the Performance variety.

You do not need the Wall Connector; you can plug into any receptical with the "mobile connector".
The mobile connector accepts the proper plug; I have 3: 110v, 30A dryer and NEMA 14-50.
I had an electrician run 50' of #6 copper wire under the house to the garage and install the NEMA 14-50 recepticle.
The charger is in the car; it pulls max 32A @ 240V which delivers 28 to 32 MPH charge rate.
The nozzle is secured to the wall in a cheapie plastic holder. Tesla charging.
Even though I have solar panels, I schedule the car to charge at night; it is full each day by 5:00AM.

 

[The Critic]

You do not need the Wall Connector; you can plug into any receptical with the "mobile connector".
The mobile connector accepts the proper plug; I have 3: 110v, 30A dryer and NEMA 14-50.
I had an electrician run 50' of #6 copper wire under the house to the garage and install the NEMA 14-50 recepticle.
The charger is in the car; it pulls max 32A @ 240V which delivers 28 to 32 MPH charge rate.
The nozzle is secured to the wall in a cheapie plastic holder. Tesla charging.
Even though I have solar panels, I schedule the car to charge at night; it is full each day by 5:00AM.

I believe the guidance on this has changed - the wall connector is now the preferred method for home charging. There is increasing commentary that the mobile connectors should not be used for daily charging because the outlets are not "ideal" for constant draws. It is safer and more reliable to have a hardwired connection, which is what the Wall Connector uses.

 

[GMFan]

View attachment 148293

Here’s what was inside feeding it. I’m not sure what size it is but maybe someone here can tell.

The wire size should be printed on the insulation of the wire.

 

[KrisZ]

OP has a 200amp main panel, the sub-panel is on a 100amp breaker, I don't think it's enough for a dedicated EV charger, which would need a 50-60amp breaker, doesn't matter if there is physical room for it, there isn't enough amps available, it would trip when another appliance, like a dryer is used.

The EV charger needs to be on the main panel.

 

[ecotourist]

OP has a 200amp main panel, the sub-panel is on a 100amp breaker, I don't think it's enough for a dedicated EV charger, which would need a 50-60amp breaker, doesn't matter if there is physical room for it, there isn't enough amps available, it would trip when another appliance, like a dryer is used.

The EV charger needs to be on the main panel.

We have a 200 Amp panel. My EV charger is on the sub-panel which supplies our baseboard heaters. But as we literally never use the baseboard heaters and intend to never use them again (except under dire circumstances) there has been no problem. The breaker could/would likely trip if we tried to use both at the same time.

We have a 40 Amp breaker for our EV charging circuit and our Tesla draws 32 Amps (which is its maximum).

Ideal situation? Perhaps not, but certainly functional. The breaker has never tripped in almost 2 years of almost daily use.

It wouldn't be a good idea to have an EV on the same circuit as a clothes dryer or something you would use from time to time.

 

[UncleDave]

We have a 200 Amp panel. My EV charger is on the sub-panel which supplies our baseboard heaters. But as we literally never use the baseboard heaters and intend to never use them again (except under dire circumstances) there has been no problem. The breaker could/would likely trip if we tried to use both at the same time.

We have a 40 Amp breaker for our EV charging circuit and our Tesla draws 32 Amps (which is its maximum).

Ideal situation? Perhaps not, but certainly functional. The breaker has never tripped in almost 2 years of almost daily use.

It wouldn't be a good idea to have an EV on the same circuit as a clothes dryer or something you would use from time to time.

My household would have zero conflict with the car on the dryer circuit.

We dont run the dryer past 10 PM and Id have the car charge from around 11 to 7 or so.

 

[pantygnome]

My household would have zero conflict with the car on the dryer circuit.

We dont run the dryer past 10 PM and Id have the car charge from around 11 to 7 or so.

Based on the labels of the breakers in OPs subpanel, there are a lot of "large" appliances that may or may not be running throughout the day (microwave, dryer, etc). and overnight (fridge, etc). Plus it looks like a lot of stacked breakers if Im seeing it correctly.

On top of possibly undersized wiring powering the panel.

Regardless of if the breaker to the sub will trip because of too much draw, I feel like the sub has other issues even without an EV circuit added.

 

[The Critic]

Based on the labels of the breakers in OPs subpanel, there are a lot of "large" appliances that may or may not be running throughout the day (microwave, dryer, etc). and overnight (fridge, etc). Plus it looks like a lot of stacked breakers if Im seeing it correctly.

On top of possibly undersized wiring powering the panel.

Regardless of if the breaker to the sub will trip because of too much draw, I feel like the sub has other issues even without an EV circuit added.

Agreed. A load calculation should be done, but even then, it is probably not the right place for it.

Unless....the OP wants to consider a load sharing device?

DCC-10 Avoids Major Home Electrical Upgrades for an EV Charging Installation

DCC-10, an EV Energy Management System, allows the addition of an EV charger in a home that would otherwise require electrical upgrades. Learn how.

dccelectric.com

 

[ecotourist]

My household would have zero conflict with the car on the dryer circuit.

We dont run the dryer past 10 PM and Id have the car charge from around 11 to 7 or so.

You should check into whether it is possible to set up your prospective EV to charge only during certain hours. I plug my Tesla in when it gets put in the garage and it stays plugged in until we use it.

I've never checked into whether I could restrict the charging hours. I keep things as simple as possible.

 

[The Critic]

You should check into whether it is possible to set up your prospective EV to charge only during certain hours. I plug my Tesla in when it gets put in the garage and it stays plugged in until we use it.

I've never checked into whether I could restrict the charging hours. I keep things as simple as possible.

You can do that, but from a code/compliance standpoint, that is not an acceptable solution.

 

[UncleDave]

You should check into whether it is possible to set up your prospective EV to charge only during certain hours. I plug my Tesla in when it gets put in the garage and it stays plugged in until we use it.

I've never checked into whether I could restrict the charging hours. I keep things as simple as possible.

You can select the charge timeframe.

Every EV Ive seen, and some PHEV's like volts have the ability to charge by selected timeframe.

Typically this cycle will coincide with the power companies cheapest rate or dedicated EV timeframe.

That window is usually around 10P-6A.

 

[UncleDave]

There are also devices designed to split load and or protect or time a given circuit.

This is one

Lectron NEMA Socket Splitter - Power Your EV Charger and High-Powered Appliance From the Same Outlet (NEMA 14-50 to NEMA 14-50 / NEMA 14-50 Splitter)Default Title

*PRE-SALE: SHIPS IN Q2 2023 COMPATIBLE NEMA SOCKETS - This Lectron NEMA Socket Splitter has a NEMA 14-50 inlet plug, a NEMA 14-50 primary socket, and a NEMA 14-50 secondary socket. CHARGE MORE CONVENIENTLY - This Lectron EV power splitter lets you use one outlet to power your Level 2 EV charger...

ev-lectron.com

 

[brianl703]

You’re going to have to add more twins to free up 2 spaces for the 2 pole breaker.

It looks like he has a 15 amp breaker just for the smoke detectors. I've never seen that done and it doesn't seem like a good idea (the breaker could trip or be turned off and you'd have no way of knowing till the smoke detectors started beeping for low battery).

Could remove that 15 amp breaker and connect the smoke detectors to a lighting/receptacle circuit like it's done everywhere else.

That frees up one space.

 

[The Critic]

It looks like he has a 15 amp breaker just for the smoke detectors. I've never seen that done and it doesn't seem like a good idea (the breaker could trip or be turned off and you'd have no way of knowing till the smoke detectors started beeping for low battery).

Could remove that 15 amp breaker and connect the smoke detectors to a lighting/receptacle circuit like it's down everywhere else.

That frees up one space.

I believe current NEC for interconnected smoke detectors requires them to have their own dedicated circuit.