What's up with HPWC?

[FlasherZ]

I am doing similar. Using a 1/0 AWG from the main panel to subpanel which are next to each other. From there 2AWG SER cable to the WC and 6AWG to my existing Clippercreek HCS60.

Just as a quick reminder: #2 copper SER is not good for the 80A charge setting (100A circuit) if it passes through or in any insulated walls, as it's only good to 95A in that case. NEC 338.10(B)(4)(a) says "Where installed in thermal insulation the ampacity shall be in accordance with the 60 degC (140 degF) conductor temperature rating."

If it's in a surface-mounted conduit or used as exposed cabling (with an appropriate sleeve where "subject to physical damage", generally below 7'), you're fine.

 

[BigMskiman]

I kept calling service centers until one had a HPWC in stock, it was Santa Barbara. They shipped it to me in Pleasanton, no charge in 3 days.

 

[K-MTG]

Just picked mine up at Costa Mesa, it was overflowing with X!

 

[TexasEV]

There is no longer a product called "HPWC". Tesla changed the name from High Powered Wall Connector to Wall Connector a while back. Regardless, it does seem a refresh may be coming soon and the Model 3 announcement could be a great time to announce it.

It's still a HPWC even after Tesla simplified the name to Wall Connector.

 

[Monkey]

I also think it's supply and demand. I bought one a couple weeks back, but have not installed it yet as my electrician hasn't been able to come do it. My install isn't all that easy, unfortunately. There were rumors of an updated HPWC a couple months back and that may also be happening, but I don't know what all they would do to make it different or better. It's still going to deliver the same power...

 

[mercc3650]

Now that the model 3 event is past, and no mention of an upgraded wall connector (previously known as HPWC), if anyone is interested in a brand new unopened TESLA wall connector, I would be willing to sell it since I heard it is on back-order. If interested, contact me at [email protected]
Will sell it for the same price as listed online $750 since it is new.

 

[engle]

Trying to get a HPWC in SoCal. Will have my electrician install next week but he doesn't want to deal with permits. He will be using 2 gauge wire (25 feet) and install a sub panel

My electrician also used 2 gauge wire, which is better (thicker) than the 3 gauge required by Tesla's installation instructions, thus even safer. I was lucky because my service panel is outside directly opposite where I wanted my HPWC in the garage. All the electrician had to do is use an extra punch-out in my main panel to run his line to the other side of the wall basically.

My second stroke of luck was buying the last HPWC in stock (at the time a few weeks ago) from Tesla Factory Service.

 

[K-MTG]

I also used 2 gauge wire but I noticed that my electrician did not attach the ground wire to the back plate as shown in the manual but the Wall Connector still has the green light so I would assume that everything is fine.

 

[engle]

I also used 2 gauge wire but I noticed that my electrician did not attach the ground wire to the back plate as shown in the manual but the Wall Connector still has the green light so I would assume that everything is fine.

I would ask Tesla if that's still OK. Whatever is driving the "green light" may not be able to detect this if it really has to be connected per the installation instructions.

 

[FlasherZ]

I also used 2 gauge wire but I noticed that my electrician did not attach the ground wire to the back plate as shown in the manual but the Wall Connector still has the green light so I would assume that everything is fine.

The connection to the back plate is for safety purposes. The unit's ground detection is done based on the connection to the terminals inside the unit. For the most part, it's not a big deal - it's just designed to add another safety mechanism - if one of the hot conductors were to short to the chassis, a ground there would provide fault current to trip the breaker.

 

[K-MTG]

The connection to the back plate is for safety purposes. The unit's ground detection is done based on the connection to the terminals inside the unit. For the most part, it's not a big deal - it's just designed to add another safety mechanism - if one of the hot conductors were to short to the chassis, a ground there would provide fault current to trip the breaker.

Hopefully it won't be a problem, thanks for the info. When I pointed this out to my electrician he said that is only needed when mounting on metal but it looks like he didn't want to loosen the bolt to attach the ground wire. He was very lazy. I should have insisted but he also got rid of the ground cable so it looks like I will just have to leave it alone.

 

[Aljohn]

I interpreted attaching the ground pig-tail as a necessary protection step. I would suggest you complete, not only for protection of the "220vac" hot, but possibly for the monitoring electronics in the HPWC. Engineers don't place grounds on a whelm.

 

[FlasherZ]

I interpreted attaching the ground pig-tail as a necessary protection step. I would suggest you complete, not only for protection of the "220vac" hot, but possibly for the monitoring electronics in the HPWC. Engineers don't place grounds on a whelm.

While many don't place them on a whim, some engineers don't necessarily understand it, or they're following some type of general rule like "every metal piece of the chassis shall be grounded".

If you look closely at the HPWC, though, you'll note that the body of the unit is insulated and it hooks into that metal plate for stability. If you don't drill a knock-out in the back of it, then there's not really any path that could energize that plate and it just doesn't matter. It's more important to have that jumper if you choose to enter the HPWC from the back with the wiring, in case the plate gets energized by an errant or nicked conductor.

I feel comfortable in saying that the ground jumper for the mounting plate isn't a big deal unless you're entering the HPWC from the back. I probably wouldn't call an electrician back onto the site to deal with it.

 

[engle]

While many don't place them on a whim, some engineers don't necessarily understand it, or they're following some type of general rule like "every metal piece of the chassis shall be grounded".

If you look closely at the HPWC, though, you'll note that the body of the unit is insulated and it hooks into that metal plate for stability. If you don't drill a knock-out in the back of it, then there's not really any path that could energize that plate and it just doesn't matter. It's more important to have that jumper if you choose to enter the HPWC from the back with the wiring, in case the plate gets energized by an errant or nicked conductor.

I feel comfortable in saying that the ground jumper for the mounting plate isn't a big deal unless you're entering the HPWC from the back. I probably wouldn't call an electrician back onto the site to deal with it.

Thanks for your FAQ, shared expertise, and advice. That said, personally I would never advise someone to ignore Tesla's installation instructions. What if they do and then something went wrong and their garage burnt down? There might potentially be liability incurred (although I'm not an attorney).

(My electrician did connect that ground, by the way. I consulted a second copy of the instructions to make sure he followed them, and took cell photos of his work with his permission.)

 

[K-MTG]

I didn't go with the permit route either but my electrician only charged me for the parts + $50 for labor for installing a larger sub panel, moving circuits from the main panel to the sub panel to make room in the main panel for 100 AMP breaker. And he ran 2 gauge cable to the wall connector.

 

[FlasherZ]

Thanks for your FAQ, shared expertise, and advice. That said, personally I would never advise someone to ignore Tesla's installation instructions. What if they do and then something went wrong and their garage burnt down? There might potentially be liability incurred (although I'm not an attorney).

(My electrician did connect that ground, by the way. I consulted a second copy of the instructions to make sure he followed them, and took cell photos of his work with his permission.)

Technically, it's an illegal (not to code) installation because manufacturer's instructions weren't followed.

As far as liability goes, I suppose someone could try to make that argument. But then again, I think there is well-established precedent that trusting an anonymous Internet forum for professional advice isn't the best approach to anything. That's why my FAQ tells you to consult an electrician and follow instructions. I don't have an electrical contractors' license (because Illinois and Missouri do not have statewide licensing schemes, although municipalities may establish their own).

But the reality of the situation is that the ground jumper from the EGC (ground terminal) to the back plate of the HPWC is belt-and-suspenders. The risk really isn't that of burning anything down, it's more of a personal safety issue to create the fault current necessary to trip the breaker should a live conductor hit the backing plate of the HPWC. Without the ground, if a hot conductor were compromised and electrified the rear plate of the unit, touching it could give a significant shock. As I've said above, though, if you haven't wired it from the back, though, it's extremely unlikely that it's even a possibility that the back plate could contact a live conductor (since they'll enter from conduit on the left side of the unit and the back of the sealed unit hasn't been compromised).

I guess I'd sum my feelings this way: if it will make you sleep better, call the electrician and ask him to install the ground jumper per the instructions. It also means there won't be a code violation of 110.3 (manufacturer's instructions). But should you be worried from a safety perspective if you don't? My answer is "no".

 

[K-MTG]

Mine enters from the side not the back

 

[FlasherZ]

Mine enters from the side not the back

Right. That's why I believe it's not a big deal. If it were wired from the back I'd want that fault current path established.

 

[McManX]

Wall connector went in stock, I purchased one, and now it is unavailable again. Tried to purchase 2 but it kept changing the quantity to 1.

 

[loganintx]

I don't want to buy a Wall Connector until they have a 48A option for it. You will be missing out on 20% extra wattage during a charge. It's an extra 5.5 miles per hour of charge time given 350Wh/mile