New House Wall Connector Install - Limited to 50A

[SyaoranDC]

My builder in Japan said my distribution board is limited to 50A but the Tesla Wall Connector says 10A to 60A. I asked if they could put in a 60A breaker but they said thats not possible in Japan.

Anyone else have experience installing a wall connector in Japan?

 

[meloccom]

I understand that Japanese electrical standards are similar to the USA.
I know the standard household voltage in Japan is 110V but I’m not sure if you can have 240V circuits like you can in The USA.
So are you talking about 50A @110V or 240V.
50A at 240V = 12Kw but Model 3 and Y are limited to 11Kw so the 50A should be sufficient. If it’s 50A @ 110V that’s only 5.5Kw but that’s still fairly good for an overnight charge.
Due to local restrictions where I live I charge at 24A @ 240V or 5.76 Kw and that is plenty.

 

[hiroshiy]

My builder in Japan said my distribution board is limited to 50A but the Tesla Wall Connector says 10A to 60A. I asked if they could put in a 60A breaker but they said thats not possible in Japan.

Anyone else have experience installing a wall connector in Japan?

I can't believe your electrical panel is limited to 50A... Is your house a detached house? Or a condo?
Most panels support 60A and upwards - you can upgrade the panel with $$$.

Also, some people mix 100V 100A and 200V 50A. It might be that the panel is 100A at 100V but 50A at 200V. In Japanese households, AC wiring has three lines - L1, N, and L2. The voltage between L1 and N is 100V, L2, and N is 100V, L1 and L2 is 200V. This is called "単3" (=single phase three lines).
If that's the case, these are what you can do:
1. Upgrade the panel with $$$ and install 200V 60A breaker to charge at 48A, maximum for Model S/3/X/Y. If your car is RWD, the maximum charging current is 32A, so the breaker should be 40A.
2. Keep the 200V 50A panel. In that case, you can charge at 200V 40A. Install 50A breaker and charge at 200V 40A. Since the panel is up to 200V 50A, when you charge your car at 40A, you have 200V 10A = about 2kW load limit for the fridge, A/C, and others.

 

[SyaoranDC]

The way the builder explained it is that most houses have 60A for the whole house. They are adding another 50A just for the Tesla Wall Connector and that the base bill for electricity will be almost double because of it.

So my house will total be 110A. They did not mention what volts but I am asking them today.

New houses in the US are 200A so was surprising the builder said Japan was 60A.

There are incentives too for the charger install but it requires us to already have the car or we don’t qualify.

 

[JayInJapan]

Okay, some incorrect info above about Japan. Standard power is 100V, not 110V. Upgraded is 200V, but not many homes here have an outlet for 200A installed.

Side note: When our homes are built, panels are installed to fit the needs of the home; power companies charge you a monthly fee based on your houses needs/main panel. The larger your panel, the larger the fee, and the fee ramps up quickly. My home is larger than usual, but our builder put in only a 50A panel; we’re in a pinch in the winter if we have guests with an extra room of heating going and can trip a breaker.

Back to our cars, there’s no way my house with a 50A panel can handle decent EV charging without some of the work Hiroshi mentioned. I had the following work done in 2014, but it’s been worth it. My car is kept in an attached garage where there’s a 150A main breaker and box, plus a 100A panel dedicated to our PowerWalls (added in 2021) and car. My P85+ (dual chargers for the OG in the room) came with a Wall Connector, capable of charging at 80A (no one needs this much power anymore—cf. Hiroshi’s suggestions). I went through Tesla at the time, and the company that did it also installs CHAdeMO all around Japan. It was impressive work, and at one point, there were 9 people in my home and garage.

I recommend getting the work done properly to avoid tripping your breakers or worse while you’re charging at night.

 

[SyaoranDC]

Okay, some incorrect info above about Japan. Standard power is 100V, not 110V. Upgraded is 200V, but not many homes here have an outlet for 200A installed.

Side note: When our homes are built, panels are installed to fit the needs of the home; power companies charge you a monthly fee based on your houses needs/main panel. The larger your panel, the larger the fee, and the fee ramps up quickly. My home is larger than usual, but our builder put in only a 50A panel; we’re in a pinch in the winter if we have guests with an extra room of heating going and can trip a breaker.

Back to our cars, there’s no way my house with a 50A panel can handle decent EV charging without some of the work Hiroshi mentioned. I had the following work done in 2014, but it’s been worth it. My car is kept in an attached garage where there’s a 150A main breaker and box, plus a 100A panel dedicated to our PowerWalls (added in 2021) and car. My P85+ (dual chargers for the OG in the room) came with a Wall Connector, capable of charging at 80A (no one needs this much power anymore—cf. Hiroshi’s suggestions). I went through Tesla at the time, and the company that did it also installs CHAdeMO all around Japan. It was impressive work, and at one point, there were 9 people in my home and garage.

I recommend getting the work done properly to avoid tripping your breakers or worse while you’re charging at night.

Thanks for that info! My builder got back to me and is putting in an additional 50A 200V panel just for the M3. I'm fine with 40A/200V. Been doing 32A/240V in the US for 5 years and never needed more. House will be on its own panel with 60A 100V.