Model S - HPWC (High Power Wall Connector)

[David29]

If by "wallcharger" you mean the Tesla Wall Connector, the charging current is set during installation for the configuration that reflects the input power (voltage and current) and the car's capability (what type of charger(s) is/are installed in the vehicle). There is no inherent advantage of the US over the UK, so far as I know, at least from the standpoint of the Tesla equipment. (I can't speak for whatever local regulations might be in the UK or elsewhere.) The installing electrician sets that charging current value. It can be set for a range of values from 12 amps to 80 amps, depending upon the situation.
Maybe yours was set incorrectly. Or maybe (and more likely) the actual circuit on which it was installed is limited to 40 amps, which would give you a maximum steady load of 32 amps. The total capacity of your house (100 amps) is not directly relevant (except that it affects how much power is available for the house as a whole, including the charger) -- what matters is the individual circuit that supplies the Wall Connector.
In the US, a house with only 100 amps capacity would often not have a spare circuit for a large load such as the charger. So people might need to upgrade their household supply to (say) 200 amps in order to feed the charger with the full 100 amp circuit needed to deliver 80 amps to the car.
In my own case as an example, my Model S has a single 40-amp charger. My Wall Connector is therefore set for 40 amps, and is fed from a 50 amp 240 volt circuit.
So -- what is the capacity of the circuit you are using?

 

[rnbetsy]

Hi David,

Thanks for that. Yes, wall connector.

That page links to instructions for a 32 Amp wall connector for the UK/EU, and an 80 Amp connector for the US.
https://www.tesla.com/sites/default...ll-connector-installation-manual-en-EU-v2.pdf

The above UK install doc shows 32A as the maximum setting during installation in the UK (on a different switch position to 32A in the US version) and all European wall connector instructions link to the max 32A installation document too.

Which got me wondering if there is a higher amperage wall connector available in the UK?

 

[tga]

There is no higher power HPWC available in the UK. For fastest charging, you need dual chargers on an old car, or enable the high-current option on a new car, and provide a 3-phase connection to the HPWC. That gives you 32A*230V*3 phase=22kW of charge power, which is essentially the same as an 80A, 240V US installation (80A*240V=19.2kW).

The limiting factor is the amount of power (kW) flowing through the on-board charger(s). On a 3-phase circuit, its delivered through 3 phases, so 1/3 the current/phase.

I don't know the exact numbers for the new single charger cars (i.e., 48A or 72A in the US), but it's the same issue.

If you are stuck with single phase power, you can't just order a US HPWC and wire it up at 80A, since the EU and US connectors are different (you can't plug a US HPWC into an EU car). Never mind that it probably wouldn't be allowed by your local inspectors.

 

[David29]

Ah, I stand corrected. i was indeed thninking in terms of amps rather than power. Did not think about 3 phases!

 

[miimura]

The bottom line is that the Wall Connector(s) in each market matches the capability of the car. In North America and Japan, the car can only take single phase up to 40 / 48 / 72 / 80 amps (depending on the on-board charger) and 277 volts. Voltages over 250V will result in the car limiting the amps so it doesn't exceed 10 / 12 / 16 / 20kW. All the cars in UK/EU/HK/AUS/etc. that have that have the Type-2 inlet have three phase on-board chargers that have current limits of 16 / 24 / 32 amps per phase depending on which on-board charger(s) you have installed. The standard Wall Connector in Europe is 32A single phase, but there is a 32A 3-phase unit available.

 

[DMC-Orangeville]

There is no higher power HPWC available in the UK. For fastest charging, you need dual chargers on an old car, or enable the high-current option on a new car, and provide a 3-phase connection to the HPWC. That gives you 32A*230V*3 phase=22kW of charge power, which is essentially the same as an 80A, 240V US installation (80A*240V=19.2kW).

The limiting factor is the amount of power (kW) flowing through the on-board charger(s). On a 3-phase circuit, its delivered through 3 phases, so 1/3 the current/phase.

Hmmm....I recall that on 3 phase systems, it's 1.73 is the multiplier (root3), not 3. so the math is 1.73*230*32 = 12.7KW of available power....

 

[Dstrohl]

This is probably covered, but my search didn't find anything..
Why is the UK Tesla wallcharger only 32A, vs the US charger at 80A? I have single phase 230V with a 100A breaker to the house. Cooker/shower/heating is all gas, so I was expecting to be able to use a higher Amp charger?

local electrical code, regulatory approvals, etc... lots of reasons that stuff is different between regions.

And, if you have a 100A breaker for your whole house, I would seriously worry about putting in a 100A circuit under that for your car, unless your load is really low.

 

[miimura]

Hmmm....I recall that on 3 phase systems, it's 1.73 is the multiplier (root3), not 3. so the math is 1.73*230*32 = 12.7KW of available power....

It's Root3 * the L-L voltage or 3 * L-N voltage.
3 * 230 * 32 = 22 kW = 1.73 * 400 * 32

 

[NullException]

From Home charging installation on the Tesla UK support pages...

A Tesla Wall Connector enables charging up to 22 kW. The achievable charge rate depends on your grid connection and vehicle configuration.

• The majority of homes have a 1-phase grid connection, allowing you to charge up to 7.4 kW or 22 miles/hour*. This is more than sufficient for overnight charging.
• Some homes have a 3-phase grid connection. This connection enables you to charge up to 11 kW or 34 miles/hour*.
• If more power is available or if you plan to upgrade your grid connection, a Tesla can charge up to 16.5 kW or 51 miles/hour*. To achieve this charge rate, the car needs to be equipped with the High power charger upgrade.

 

[DMC-Orangeville]

It's Root3 * the L-L voltage or 3 * L-N voltage.
3 * 230 * 32 = 22 kW = 1.73 * 400 * 32

Apology.... forgot that it could be 230V L-N....which is 400V L-L in the UK. In North America it is not unusual to have a 240V (230V) 3 phase delta. My math would have been applicable there.

 

[TR5642]

The rule of services that 'Machines break, Software has bugs and People make mistakes' is true. After verifying that your input lines have correct voltage and ground is OK, then call Tesla.

This is an example of where a 14-50 installed on the same line would be good backup to an HPWC.

As much as it makes sense for a thoughtful owner, my electrician was quite pointed that code does not allow that configuration unless the whole circuit were rated for the max power of the HPWC AND the 14-50 which is then a rather exotic circuit. Now, if you're doing the work yourself and not pulling a permit, and using your brains to not use both at once (I saw a pic of one such installation with a label warning against using both attached to each) it would work and be smart. But if you're going to pull a permit, pull two circuits. Not too much extra if you've got the capacity. (And if you get a second EV you CAN plug it in at the same time)

 

[Don85D]

The code is the code and it doesn't always make sense. In a house there can be multiple 15 amp receptacles strung on a single 15 amp circuit. Over loading the circuit trips the breaker keeping the line safe from overheating at all times. Multiple 14-50s or HPWCs would look the same to me. Use one or more as you like just keep the current low to avoid tripping the breaker.

In my case the 14-50 is inside the garage and the HPWC outside. We have only one Tesla and depending where it is parked we have a convenient access point for charging.

If you are not doing the work yourself then stick with code for approval of the permit. It's much less trouble than asking for an exception.

 

[HumanGenome]

Installed

 

[S3XY]

As much as it makes sense for a thoughtful owner, my electrician was quite pointed that code does not allow that configuration unless the whole circuit were rated for the max power of the HPWC AND the 14-50 which is then a rather exotic circuit. Now, if you're doing the work yourself and not pulling a permit, and using your brains to not use both at once (I saw a pic of one such installation with a label warning against using both attached to each) it would work and be smart. But if you're going to pull a permit, pull two circuits. Not too much extra if you've got the capacity. (And if you get a second EV you CAN plug it in at the same time)

I would think an A/B switch would solve that requirement.

 

[miimura]

I would think an A/B switch would solve that requirement.

It could, but you still have a problem if a 14-50 is protected by a 100 amp breaker. You would be more likely to get a sub-panel fed with 100 amps passed with breakers for a 14-50 and full power HPWC. It would be over-subscribed, but each one would be safe and if you did use them simultaneously, the breaker in the main panel would trip.

 

[LilWanFu]

Upgraded main to 200 AMPs with a 60 AMP circuit for the HPWC. It's a stone's through from the main feed so I didn't have another cutoff switch in between.

 

[ma47]

Are you looking to buy a new Tesla or an older one? The newer ones (Model S since April and all Model X) have 48 or 72 amp chargers. Older Model S cars had either 40 or 80 amp chargers.

1. You can only charge at 80 amps if you have an older Model S with the 80 amp (dual charger) charging option and the appropriate EVSE, such as the HPWC. There are other EVSEs that could be used as well but they would require the use of the J1772 adapter since only Tesla's UMC and HPWC use Tesla's proprietary charging port/connector. Newer Teslas would charge at up to 72 amps with the HPWC and appropriate wiring if you get the high amperage charger upgrade. By default, they would charge at up to 48 amps using an EVSE or 40 amps with the UMC.
2. Some people will tell you that the HPWC looks better that the UMC, lasts longer, etc. The UMC has its own benefits as it is smaller, more portable and can be used almost anywhere there's an electrical outlet. The HPWC could allow you to charge at up to 72 or 80 amps, depending on the vehicle. The UMC will only go to 40 amps maximum. If you don't have dual chargers (80 amps) or the 72 amp charging option on newer Teslas, then you'd only be able to charge at 40 to 48 amps maximum with the HPWC.
3. As I mentioned above, some like that the HWPC is hard-wired. That could be a benefit but also a liability. If it has a problem, you'll need Tesla or an electrician to come out and service or replace it. With the UMC, you could take it into a Service Center and swap it out yourself. The cable lengths also differ between the UMC and HPWCs.

Most owners that I know use the UMC at home and never unplug it unless they are going on an extended road trip where Superchargers or other public charging are not available. I'll be going on a 2000 mile r/t road trip next week and won't really need to unplug and take the UMC since the route is covered entirely by Superchargers (and other chargers could be used with the J1772 adapter). When traveling to places like Nebraska where there are currently no Superchargers and public charging is rather sparse, I would have to take the UMC in order to charge for the return trip.

I'm new too, get the car in about 2 weeks. Great info here. I did not get the high amperage upgrade, but plan on installing my HPWC so that it can support up to 80 amps. Is it fair to assume the car will automatically draw only the 48 amps it is capable of handling?

 

[MP3Mike]

Is it fair to assume the car will automatically draw only the 48 amps it is capable of handling?

Yes.

 

[tga]

But if you are "plan on installing my HPWC so that it can support up to 80 amps," it still needs to be installed on a 100A circuit, even if the car is only drawing 48A.

 

[Maximapolak]

Can I legally wire the HPWC myself?