HPWC Installation Question

[Shodan01]

Question - My home is wired for a 200 amp setup and the installer who came out said that I should only use a 70 amp breaker and set the dial on the HPWC to 60 amps (yielding 42 amps to the X).

My home is 99% Natural Gas - Heat, Water, Stove, Oven etc. The items on electricity outside the "norm" are pool pump which I can program to charge at any time.

My question - What are most of you installing? I want to pull 40-50 amps for my normal charging, however want the ability to charger faster as needed (especially with the ability to schedule the pool pumps etc).

Anyone seeing an issue with this?

 

[Wshowell]

I’ve had my Wall Connector AKA HPWC for 2 years now. We are an all electric household with a spa, electric water heater, dryer, water well etc. I wanted to be extra cautious in case we were running the spa while drying clothes and charging the car so I set my system up with a 40 amp. breaker, set the HPWC to at 32 amps and the car to 32 amps as well. I’ve never once had any issues or concerns with it being fast enough. I charge at 23 mph and my friend’s 3 we tested charged at 25 mph. I’d suggest saving money and going with the same setup and save the fast charging for supercharger. I also have superchargers within 10, 50 and 100 miles from me in all directions so I can always grab a quick fill up if I need to race out of town on a trip. If you’re not in a similar sotuation I can see how you might feel differently.

 

[SSedan]

80% rule for continuous load, 70amp circuit you can only set the HCWC to 56amps. Which is 56 amps available to the car.

 

[Shodan01]

I already have the HPWC and like the ability to charge at the 100 amp (80 to X) when needed. The electricians concern was that the house is set up on a 200 AMP main breaker and he didnt want to tax that too much. Personally I think he was just being super cautious but wanted to get your opinions....

 

[ronm2948]

It sounds like your home could easily handle a 100A breaker, but the issue might be code. I think that you might need to “prove” that your existing loads can coexist with the HPWC with a breaker that size. I would probably try to push for the 100A anyway ... while 70A (56A usable) would be enough almost all the time, it would be nice to be able to charge as quickly as possible in case you ever need it.

 

[Batt Car]

Your electrician is just being super cautious. I have 2 HPWCs, one for my X on an 80 amp breaker (charges my X at 64 amps) and another for my wife's 3 on a 60 amp breaker (charges the 3 at 48 amps). Our house is like yours, 200 amp, mostly gas service. I put a graphing amp meter on for a week in the hot summer (air conditioner is the only other big draw electric appliance) and with everything running I never hit a peak of more than 120 amps (and that was a spike when the compressor kicked on with everything else on full load). I say you can safely up the breaker and charge rate.

 

[TexasEV]

No Model X would need a 100A breaker for maximum charge rate, because the biggest charger any Model X has is 72A so a Wall Connector on a 90A circuit would provide that. If you only have a 48A charger in your car the biggest circuit that you would benefit from is 60A. You haven’t said which charger your Model X has.

 

[BrokerDon]

Your electrician should do a “load calc” to determine how big a breaker he can install on your 200A panel. We have a 1st gen HPWC on a 100A breaker our 200A panel that can charge our dual 40A charger equipped 2015 P85D. However, we RARELY charge at 80A for emergencies, instead charging nightly at 60A to keep our HPWC plug and Tesla charge port cooler (they get hot at 80A). Not sure 100A breaker to get 80A charge rate worth the higher wire / installation cost. 60A plenty fast IMHO.

 

[bob_p]

For overnight charging, 32A (standard mobile connector on a 40A circuit), 40A (14-50 connector on a 50A circuit) or 48A (HPWC on a 60A circuit) should be enough to fully recharge a vehicle overnight (assuming charge is typically kept between 10-90%).

Charging faster should only be needed for mid-day recharges.

We've been charging our S 100D and X 100D using 40A and 48A - and that's been fine.

Note that we installed our referral HPWC last week, using the cabling for a 14-50 outlet that was charging our X. Because the electrical line can handle 60A, the electrician replaced the 50A breaker with a 60A breaker, so we were able to increase the charging rate from the HPWC to 48A (higher than the 40A we were getting with our 14-50 connector).

The electrician tried to get us to spend an additional $2000 to install a new 100A line from the new HPWC to the breaker panel, and we declined that, because we are confident 48A of charging is fast enough for our needs.

And, if we ever needed to charge faster, we have a supercharger only a few minutes away...

 

[SSedan]

In cold climates the ability to run more amperage helps speed warmup and charging, and the higher amperage seems to warm the battery more for better regen.

 

[BrokerDon]

The electrician tried to get us to spend an additional $2000 to install a new 100A line from the new HPWC to the breaker panel, and we declined that, because we are confident 48A of charging is fast enough for our needs.

And, if we ever needed to charge faster, we have a supercharger only a few minutes away...

Excellent choice!

$2,000 to increase your HPWC circuit from 60A to 100A HPWC breaker just doesn't make financial sense. Our HPWC location luckily was only 2 feet from its breaker panel so no additional installation charge to install 100A.

Also our fully loaded showroom floor "inventory" 2015 MS P85D came with dual 40A chargers so 100A circuit breaker / 80A HPWC capability made sense. Otherwise 50A or 60A is plenty for overnight charging for 99% of Tesla owners. We only charge nightly at 60A instead of the 80A to keep the HPWC connector and Tesla charge port cool so they last longer. At 80A they get very warm which isn't good for the plastics, wires and electronics in our Tesla or HPWC.

 

[DoctorVenkman]

The only reason you would ever need more than a 40 amp circuit is if you'd be doing multiple trips in a single day that total over 200 miles and don't have much time in between to charge. I live in Los Angeles which is a biiiig city and I've never come close to driving 250 miles in a single day. It's a very limited use case.

The closest I've ever come to needing more than 40 amps is when I went driving from the west side up to Malibu, through the canyon, down the 101 and back to the west side. Then in the evening I drove down to Orange County and back. At the end of all that I still had enough charge where I could have easily done another round trip within the city. I only would have needed more than 40 amps if I went on ANOTHER 100+ mile round trip in between my morning and evening trip AND there were no convenient superchargers along the way.

Again, I don't think it's worthwhile unless you are of the limited use case where you will be driving multiple long trips per day with time to charge at home in between. Or you just like to see bigger numbers on your screen.

 

[Shodan01]

I have a 2018 P100D so I presume it has the highest rate of charging (total NOOB to Tesla’s so unsure what diff years/battery sizes offered). I am happy to run mine at 40 amps for usual charging (I drive 5 min to work daily). The challenge is that I sometimes have 2 hours notice to drive 130 miles to another office so I wanted the opportunity to charge at 80 amps would be helpful.

 

[DriveMe]

I don’t think Tesla’s come with dual chargers anymore (unless you had one installed afterwards). If you have a single charger in your car then the maximum rate you can charge at is 48 Amps on a 60 Amp (or higher) circuit.

 

[SSedan]

I have a 2018 P100D so I presume it has the highest rate of charging (total NOOB to Tesla’s so unsure what diff years/battery sizes offered). I am happy to run mine at 40 amps for usual charging (I drive 5 min to work daily). The challenge is that I sometimes have 2 hours notice to drive 130 miles to another office so I wanted the opportunity to charge at 80 amps would be helpful.

Older S was available with one or two 40amp chargers so 80amp possible.
Current is 48 or 72 max from a single. You should be able to tell from your charging screen.
P100D I would presume is 72amp.

 

[DriveMe]

I think even P100D now comes with a single 48-Amp charger from what I've read.
Anyway, it's very easy to check. @Shodan01 - if you already have the car, please try this:

Without plugging in the car, go to the Charging screen and try changing the Charging Limit. What's the highest value you can set it to?
If it's 48 Amps, then you have a single charger and that's the highest current you can possibly get from your HPWC. No need for a circuit higher than 60 Amp.

If you don't have the car yet, then ask your Delivery Advisor about the type of charger installed in the car you are getting.

 

[Shodan01]

I was charging at 72 amps with 100am breaker and wall adapter set to highest setting with no issue.

 

[mambro]

I think even P100D now comes with a single 48-Amp charger from what I've read.

That matches what Tesla has posted: Onboard Charger

 

[DriveMe]

I was charging at 72 amps with 100am breaker and wall adapter set to highest setting with no issue.

That’s great then! If you are certain that you have a 72-amp charger in your car, then you can take advantage of a 90-amp (or higher) circuit if you really want to get the maximum charging rate.

My home is wired for a 200 amp setup and the installer who came out said that I should only use a 70 amp breaker and set the dial on the HPWC to 60 amps (yielding 42 amps to the X).

The numbers don’t add up.
If the circuit and wiring is rated at 70 amps then you should be able to charge at 56 amps. If the circuit is rated at 60 amps then the charging current will be 48 amps. It’s 80% of whatever the circuit is rated for, up to the limit of your charger.

Have another electrician come over and provide a quote. Compare the two.

 

[bob_p]

Our 14-50 line had cabling capable of handling 60A. So when we installed the HPWC using that cabling, our electrician increased the breaker size to 60A and configured the HPWC for 60A - giving us 48A for charging.

If the cabling can support 70A, you should have a 70A breaker and set the HPWC to 70A, and be able to get 56A for charging (if your onboard charger can support that).

Get another Tesla recommended electrician to review the installation and get the correct breaker and HPWC configuration.