How many amps to setup 220 In the garage?

[berkeley_ecar]

Our 6 unit condo, though new, has a 400A panel supplying 6 separate units. 50A is a high as I can justify, but that should serve nicely. Here is the new outlet box, before and after I added a StarBoard cover that I designed for it, which dresses it up and will serve as a hanger for the electrical cable.

 

[Jashev]

I'm curious as to how many people have a service panel that can accommodate an additional 90amp circuit for the HPWC? I have a 200amp panel, where there are a lot of houses in the neighborhood that only have 100, and there was barely enough capacity for the 50amps for the NEMA 14-50.

I have a 200 amp main panel in the house with two 100 amp sub-panels, one of which is in my garage. That is where I wired my HPWC as well as a NEMA 14-50 outlet (to use as a backup if the HPWC fails). Putting your 50amp breaker in your main panel probably is squeezing things a bit. The sub-panels alleviate that problem.

 

[strider]

I'm curious as to how many people have a service panel that can accommodate an additional 90amp circuit for the HPWC? I have a 200amp panel, where there are a lot of houses in the neighborhood that only have 100, and there was barely enough capacity for the 50amps for the NEMA 14-50.

That's why I always tell people to figure out what their panel will support before they just order X circuit. If you can get a 30A circuit in there as-is whereas installing a 50A or higher will cost your thousands in wiring and panel upgrades, just go w/ the 30A. 20mph vs 30mph of charging speed won't matter to most.

When we lived in 60+ year old Bay Area houses one 30A circuit was the best we could do and we survived years w/ 2 Teslas this way. We would just alternate nights plugging in.

Now we have a 200A panel in the house and a separate 100A service in the shop so we have plenty of power. We installed 2 50A's in the garage because it was simple.

 

[drklain]

Agreed. A lot of people don't understand it and having an electrician take a look and determine what you can do is always helpful. In my case my single family home was built in 1989 (not by me) but the service could support a 60 or 100 amp breaker. I chose to put in a 60 amp circuit (supporting 48A charging) since that is what my car can accommodate, but we ran the wiring to support a 100A circuit in case I buy a second Tesla and want to load share two HPWCs. At that point I'd just need to daisy chain the second unit off the first and swap out the breaker in the main panel.

 

[TR5642]

I'm curious as to how many people have a service panel that can accommodate an additional 90amp circuit for the HPWC? I have a 200amp panel, where there are a lot of houses in the neighborhood that only have 100, and there was barely enough capacity for the 50amps for the NEMA 14-50.

LOL. I had an old panel with 100A service to the house. Hopeless. Had to pull 200A new service then went ahead and put a HPWC AND 14-50 circuit in (hey go for future proofing/backup)

 

[BrokerDon]

I'm curious as to how many people have a service panel that can accommodate an additional 90amp circuit for the HPWC? I have a 200amp panel, where there are a lot of houses in the neighborhood that only have 100, and there was barely enough capacity for the 50amps for the NEMA 14-50.

Our 3,200 sq. ft. 2006 built home was built with a 200A 240V main service panel ("MSP"). There were so many circuits they added a 100A subpanel next to the MSP. After all the improvements were completed including a 30A 120V outlet for our RV and BBQ island with full kitchen, we had ZERO "spare" circuit breaker slots in both our 200A MSP and 100A subpanel.

Before we bought our Tesla, I had 3 Tesla approved electricians come to our house to verify we could install a 100A / 240V breaker for an 80A / 240V Tesla High Power Wall Charger ("HPWC"). 2 of the 3 electricians confirmed we could via a "Load Calc" of our panels and circuits AND "doubling up" some smaller breakers... Which is how our HPWC was installed with building permits & passed electrical inspection. Its worked perfectly, typically charging our 2015 Model S P85D with dual chargers overnight at 60A / 240V (not 80A to extend the life of the HPWC cable / plug + our Tesla's plug receptacle).

The 3rd Tesla electrician said we needed to upgrade our MSP to 400A which would have cost a LOT more money. The only reason we'd upgrade our MSP would be if we add a 7 kW solar... which would require a panel upgrade to either 225A "solar ready" panel or a "standard" or "solar ready" 400A MSP. It would make sense to upgrade the MSP for solar since the MSP upgrade would qualify for a 30% solar tax credit since it would be part of the solar installation.

 

[gavine]

So if you are sharing circuits - dangerous. If your house supply is already maxing out - dangerous (even though you're probably charging at night when the other things aren't drawing as much)

I'm not an electrician, but I don't know if "dangerous" is appropriate here. From what I understand, the circuit breaker will trip if you overload the circuit. What is dangerous is if your wiring is too thin....it can overheat before the breaker pops. So, as long as the wire can support the load for which the breaker is rated, I wouldn't say its dangerous.

Please correct me if I'm wrong.

 

[USMC_Mustang]

When I got our new 2016 Model S 90D I also had the "Tesla-approved" electricians come out to discuss installation. Of the (only) two in the area, neither knew what it world they were talking about. Made me question what "Tesla-approved" means. I finally called our go-to electrician who came out and installed a 240V/50a NEMA 14-50 outlet in the garage which not only works perfectly, but was half the price of the "approved" people.

 

[WARP 10]

Our 3,200 sq. ft. 2006 built home was built with a 200A 240V main service panel ("MSP"). There were so many circuits they added a 100A subpanel next to the MSP. After all the improvements were completed including a 30A 120V outlet for our RV and BBQ island with full kitchen, we had ZERO "spare" circuit breaker slots in both our 200A MSP and 100A subpanel.

Before we bought our Tesla, I had 3 Tesla approved electricians come to our house to verify we could install a 100A / 240V breaker for an 80A / 240V Tesla High Power Wall Charger ("HPWC"). 2 of the 3 electricians confirmed we could via a "Load Calc" of our panels and circuits AND "doubling up" some smaller breakers... Which is how our HPWC was installed with building permits & passed electrical inspection. Its worked perfectly, typically charging our 2015 Model S P85D with dual chargers overnight at 60A / 240V (not 80A to extend the life of the HPWC cable / plug + our Tesla's plug receptacle).

The 3rd Tesla electrician said we needed to upgrade our MSP to 400A which would have cost a LOT more money. The only reason we'd upgrade our MSP would be if we add a 7 kW solar... which would require a panel upgrade to either 225A "solar ready" panel or a "standard" or "solar ready" 400A MSP. It would make sense to upgrade the MSP for solar since the MSP upgrade would qualify for a 30% solar tax credit since it would be part of the solar installation.

Here's an option for adding a solar system without a panel upgrade:

Renewable Meter Adapter | San Diego Gas & Electric

The hitch is that, as far as I can tell, it's only available from SDG&E, and it's $1300. We were looking at adding capacity to our existing system and this was recommended, as our existing panel was maxed out. We have an entire street in our development (not mine) with 3000Sqft houses with only a 100amp panel. Malpractice by the developer.

 

[BrokerDon]

Here's an option for adding a solar system without a panel upgrade:

Renewable Meter Adapter | San Diego Gas & Electric

The hitch is that, as far as I can tell, it's only available from SDG&E, and it's $1300. We were looking at adding capacity to our existing system and this was recommended, as our existing panel was maxed out. We have an entire street in our development (not mine) with 3000Sqft houses with only a 100amp panel. Malpractice by the developer.

FYI the written quotes we received for upgrading to a new 225A "solar ready" panel or 400A panel were significantly less than $1,300.

YMMV

Professional driver, closed course.

You won't lose your doctors, you won't lose your insurance, and your insurance rates won't go up. LOL

 

[TR5642]

I'm not an electrician, but I don't know if "dangerous" is appropriate here. From what I understand, the circuit breaker will trip if you overload the circuit. What is dangerous is if your wiring is too thin....it can overheat before the breaker pops. So, as long as the wire can support the load for which the breaker is rated, I wouldn't say its dangerous.

Please correct me if I'm wrong.

First a disclaimer: I am not an electrician. Competent handyman at best who's spent some time researching and discussing with real electricians

As I understand it, in theory yes you are correct. But apparently the code writers find the risk too high. I think the issue is that with such single high current loads from an EV charger (vs a lamp here, a TV there), that are classified as 'continuous', bad things can happen. From my understanding it is quite common for people to put multiples on a circuit and just manage it properly. But inspectors won't sign off on a permit for that