Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Getting a separate HPWC

This site may earn commission on affiliate links.
I have finalized and have a delivery window of March or April. I am getting the 85 kW version with twin chargers. However, I have not yet bought a high-powered wall connector. Now that there is a $1000 credit towards electrical installation, I am thinking of getting the HPWC separately.

Does anyone know how I can order this? There does not seem to be any place on the website.
 
If you are electrically and mechanically talented (not all thumbs), you can build your own 75A J-1772 OpenEVSE:
http://code.google.com/p/open-evse/wiki/75AOpenEVSE

I was able to buy a 2nd J-1772 adapter from Tesla, for $95 that I just leave on the J-1772 cable
Cost for the 75A OpenEVSE was about $650, add in the extra J-1772 the total is $750.
Still under the $1200 for the Tesla HPWC

Differences:
obviously the OpenEVSE is not UL approved (but is built with UL listed parts)
You don't get the Tesla connector with the button to open the charge port door
It's 75A versus 80A (very little difference but the J-1772 is only certified to 75A)

That's about it...

Here it is charging my Dual charger Model S

image.jpg
 
Just call Lisa at the TMC service center in Mississauga...she'll put your name on the list...you should consider having your electrician wire your garage for it now...he can slap a NEMA 14-50 outlet on it for now so you'll be able to charge at a 40 amp rate...not a great idea to rely on a 110v charge...you'll probably add charge anxiety to your range anxiety...
 
Soon after I finalized, I phoned Tesla to see if I could add a HPWC later. They said it would be no problem as an add-on closer to delivery time (as long as it is not on back-order).
I agree it would be important that the electrician has an interim solution if the HPWC is delayed (eg NEMA 14-50).
The HPWC (I think) has the added convenience of only plugging one end in each day (car end) while keeping the mobile connector in the car all the time. Using the mobile at home with a 14-50 would be less convenient, plugging in two ends each day and then storing it in the car, if I understand things correctly.
 
If you are going to keep the mobile connector in the car, that is indeed an advantage to getting an HPWC - or a second mobile connector. I kind of thought that's how I'd use the Roadster before I bought it.

But it only took a day of that to realize that there are very few days that I drive over 200 miles. I only put the mobile connector in the car when I go on a road trip; the rest of the time I leave it in the garage, plugged in. Remember too that you can leave the J1772 adapter in the Model S (it doesn't require the mobile connector).

We only have a single mobile connector for the Roadster, and a single mobile connector (well, plus the J1772 adapter) for the Model S. We have never wished we had an HPC or HPWC. The only time I've ever wished for a second mobile connector is when I get in really late from a road trip, and have to pull out the mobile connector and get the car plugged in before I can go inside. That's really not so bad.
 
Last edited:
I agree with ChadS, from day one with the Roadster I could easily get by with 40A instead of 70A. Same with the Model S. Every morning the car is full, and it's very rare to need full power.

Also, it's a bad idea to unplug the UMC every day. The NEMA 14-50 plug is NOT rated for repeated connect/disconnect cycles. Leave the UMC in your garage unless you're going on a road trip. These days there are enough J1772's out there that you can use them in the event of "emergency". (Not that I've ever had one.)
 
Thanks, lot's of useful information. All I know about household electricity is "don't stick a fork in there".

I am having someone from Mr. Electric come to my house next week to find out exactly what they need. Tesla says they are recommended local electrical guys.

I was hoping to get someone from Mr. Fusion to come by, but they are not quite ready.
 
Thanks, lot's of useful information. All I know about household electricity is "don't stick a fork in there".

I am having someone from Mr. Electric come to my house next week to find out exactly what they need. Tesla says they are recommended local electrical guys.

I was hoping to get someone from Mr. Fusion to come by, but they are not quite ready.

I had my 14-50 installed by Mr. Electric and they prepped it for the HPWC. Smooth experience, no issues.
 
How did they "prep" your 14-50 for HPWC ? Although not technically up to code, I was thinking of running a 100Amp breaker with appropriate AWG cabling to a 14-50. Then, when I purchase a HPWC, I could simply swap out the outlet.

Please don't do that. Please don't encourage the others to do that. It is a safety hazard and can invalidate your homeowners' insurance.

Tesla published temporary instructions that consisted of installing a 50A breaker, installing the appropriate conduit (1") with #2 or #3 AWG wiring, to the location where the HPWC would be installed. A full-size junction box is mounted there, where roughly 1' of extra conductor is installed. The #2/#3 is interconnected to a temporary run of #6 which connects to a surface-mounted NEMA 6-50 receptacle below the junction box. Tesla supplied a NEMA 6-50 adapter (in addition to the 14-50 and 5-15) for free to those who had ordered the HPWC with the car. When the HPWC arrives, the electrician simply removes the junction box and temporary outlet, and connects the HPWC directly to the #2/#3, then swaps out the breaker for a 100A breaker.

Electricians use 50A breakers all the time, so they can put them back on the truck. Even if they do charge you for it, a 50A breaker is usually only $15 or so for most panel types.

According to NEC (and I assume CEC as well), a NEMA 14-50 or 6-50 receptacle may not be connected to a branch circuit with a higher rating than 50A.
 
Last edited:
Update: So my red delivery button appeared last night. After going through the process, one page said that the HPWC would be sent to me before the car arrives.

That would certainly be good. I hope it happens. Otherwise, I'll probably be on 110V until the electrician sets it all up.
 
What is the thinking behind that?

The circuit breaker provides the protection for the current rating going through it, so that it doesn't allow the cord, plug, or receptacle to catch fire.

In fact, the only exception permitted for a breaker to be larger than a receptacle rating is where a 20 amp, 125V circuit feeds multiple NEMA 5-15 receptacles.

- - - Updated - - -

And if I am not mistaken you are supposed to have a NEMA 14-50 on a dedicated circuit. I think the same goes for the 6-50 plug.

This is not true. There is no limit to the number of 50A receptacles that may be connected to a single branch circuit - but code does say you may not draw more than 40A of continuous load through a branch circuit rated for 50A. So don't use two of them at the same time. I've seen where several receptacles have been installed on the same circuit, just for ease of use purposes -- if I park my car out back, out front, etc.

It's not recommended, and if you have an FPE or Zinsco panel, I'd never do it... but that's another matter.
 
Okay, I get it. Sensible. (I bought a copy of the CEC recently but have only had time to skim it - I do more electronics than power stuff!)

So if I wanted to add a NEMA 14-50 to my garage's 100A circuit, I would have to add a subpanel.

But if I wanted to add an HPWC in parallel with my HPC, that would be okay as long as both cars don't charge full power at the same time?
 
So if I wanted to add a NEMA 14-50 to my garage's 100A circuit, I would have to add a subpanel.

I speak only from the NEC perspective (keeping track of one giant codebook is a PITA enough), but that is correct. But we'd probably have to dive down more into how your garage's 100A circuit is structured. I hope you don't have any 15-amp or 20-amp receptacles on a 100A breaker - that's a no-no.

But if I wanted to add an HPWC in parallel with my HPC, that would be okay as long as both cars don't charge full power at the same time?

According to the NEC, yes. As long as the presented continuous load doesn't exceed 80% of the branch circuit's breaker rating.
 
I speak only from the NEC perspective (keeping track of one giant codebook is a PITA enough), but that is correct. But we'd probably have to dive down more into how your garage's 100A circuit is structured. I hope you don't have any 15-amp or 20-amp receptacles on a 100A breaker - that's a no-no.

Right now the circuit is dedicated to the Roadster HPC (now a J1772). Our code requires a cutout switch within sight of the charger, so there's this big ugly switch beside it.

charger.JPG


According to the NEC, yes. As long as the presented continuous load doesn't exceed 80% of the branch circuit's breaker rating.

If I tell both cars to charge only at 40A, then it shouldn't be a problem, right? Or I can charge just one at full power if needed.
 
If I tell both cars to charge only at 40A, then it shouldn't be a problem, right? Or I can charge just one at full power if needed.

Sorry, maybe I wasn't being clear. If you wanted a 14-50 in parallel with your HPC, you need to change to a 50A circuit breaker and turn your HPC down to the 50A circuit setting. You cannot have a 50A receptacle on a larger breaker.