Yes, I designed an adapter. It was discussed here last year. I showed some pictures and a couple of videos. I really thought this new wall connector would render it useless, but I was happy to discover that it worked.
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New Wall Connector :)
- Thread starter pluginx007
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FlatSix911
Porsche 918 Hybrid
sowbug
Member
Had two new Wall Connectors installed today, replacing my first-gen HPWC after our second Tesla arrived on April 30. They're connected to a single 100A circuit (80A available). Just to confirm what people were hoping was the case:
From this observation, I confirm that the system appears to be reasonably smart. The allocation of power between the two connectors is dynamic, and it follows common-sense expectations.
After Step 2 I was briefly concerned that simply plugging in a second car (regardless of whether it was actually drawing any current) would halve the available power to the first. That would have been a bummer, because we intend to leave both cars plugged in whenever they're parked, so a dumb (available power / # of connectors) formula would have made our car charger upgrades pointless. Fortunately, Steps 3 and 4 confirmed that that was not the case.
My next experiment will be to plug in a depleted car while a charged car is plugged in. In that case I want to see the depleted car charge at the full 72A/80A, just as if the charged car weren't plugged in at all. If that experiment is successful, then I'll be completely happy with the connector purchases.
- Plug in one car, and it indicates 80A available.
- Plug in the second car, and each indicates 40A available.
- Let them both start charging, and they'll each draw about 40A (I saw 40/40 and 38/42).
- Stop one car from charging using the app, and the other car will gradually draw more current. I let it get to 46A before ending the experiment.
From this observation, I confirm that the system appears to be reasonably smart. The allocation of power between the two connectors is dynamic, and it follows common-sense expectations.
After Step 2 I was briefly concerned that simply plugging in a second car (regardless of whether it was actually drawing any current) would halve the available power to the first. That would have been a bummer, because we intend to leave both cars plugged in whenever they're parked, so a dumb (available power / # of connectors) formula would have made our car charger upgrades pointless. Fortunately, Steps 3 and 4 confirmed that that was not the case.
My next experiment will be to plug in a depleted car while a charged car is plugged in. In that case I want to see the depleted car charge at the full 72A/80A, just as if the charged car weren't plugged in at all. If that experiment is successful, then I'll be completely happy with the connector purchases.
CmdrThor
Active Member
Thanks for the information.
Do you have to use the top entry bracket in order to daisy chain, or is it possible to use the low profile bracket?
It wasn't really designed to daisy chain with either entry. You could try, however.
CmdrThor
Active Member
The new Wall Connector is absolutely designed to daisy chain and is the exact functionality sowbug described in his post.
You do not daisy chain the units. The top entry bracket has only two terminals per conductor -- one to accept the wiring coming from your panel, and one for the short pigtail wiring that feeds power into the unit itself.
Two units on individual 100A branch circuits may share a single 100A feeder back to the service panel from a subpanel and 100A may be used in the load calculations (vs. 200A) - this is the preferred method. An alternative is to use a sufficiently-sized junction box and insulated connectors to join multiple units to a single set of input conductors, but some inspectors may reject that based on NEC 210.17 which says that EV charging requires a separate individual branch circuit for an EV charging point of attachment.
To @sowbug: can you share information about your installation? How are the HPWC's connected in your case? Subpanel in the garage - or junction box - or some other method? Can you share pics?
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Do you have a reference for this? Tesla is telling me differently and I'd like a reference, or even better to see it in practice with someone who has connected the units. I'm happy to be corrected here, it will give us more options.
I am told the Wall Connector is designed for what the NEC calls a "Load Management System", which means that multiple units will coordinate to draw a maximum current as an entire system.
"Daisy chaining" has specific meaning, in that you connect conductors to the first unit's "input", then connect conductors from the first unit's "output" to the second unit's "input". While the Wall Connector has a "daisy chain" for the data bus, it does not have this capability for the power conductors in that there are no "output" lugs for power conductors on the units.
CmdrThor
Active Member
Yes, the manual page 29. https://www.teslamotors.com/sites/d...ll_Connector_Installation_Manual_EN_JP_ES.pdf
Here is the top entry bracket:
It doesn't say specifically, but my assumption is the wiring going out the bottom goes to the next Wall Connector.
Nope, that is showing both of your options for the incoming power, you can use one not both. Actually I don't think you can feed the power into the bottom of the top entry bracket, the power cables coming off the bottom are the ones that go to the WC unit itself.
As far as the "You can connect the Wall Connectors in series in a daisy chain configuration." note in the manual that is talking about the data communication, or "local network", between WCs, not the power itself.
This is not what you think it is. The bottom cables go to the HPWC. There is no 3rd outlet for daisy chaining.
*however* there may be room for 3 polaris connectors when using the top mount bracket. I didn't try however.
edit: Now that I think about it, it would be extremely hard to use polaris connectors. Tesla put that loop at the bottom of the top mount bracket which would make it near impossible to snake the other leg of the connection back out through the bottom entry.
CmdrThor
Active Member
So if it doesn't actually daisy chain, how is the circuit breaker shared? The manual isn't very clear on this part.
There's no conduit out the bottom of the top entry bracket, and putting the conductors for the next HPWC into the same conduit will result in derating of your conductors for 4 current-carrying conductors.
You'd need to take it up to a junction box north of the HPWC.
You could use the rear/bottom entry to route the wires through for another conduit coming out the bottom. Of course the existing loop on the top mount bracket makes it difficult.
Tesla has admitted that the wording was confusing. They mean sharing a common breaker from the main service panel (e.g., a feeder) and the same value in the load calculations. The breaker *can* be shared if your inspector will allow you to use insulated connectors to connect multiple HPWC's, but that's not guaranteed (and seems to be against 210.17 in the NEC).
As I noted upthread, the preferred way to do this is to use a subpanel with 100A branch circuits located near the HPWC's, and then a single 100A feeder going back to the service panel.
@sowbug should be able to confirm this, but I think you cannot daisy chain the power connections. Those have to be run separately. You do run the two signaling wires daisy chained through the units. I don't know if those come in through the same entry point as the power connections.
Let's say your main panel is not very near your garage. You can put one 100A breaker in the main panel and run one 100A line to the garage (instead of two runs). That goes to a subpanel. In that subpanel, you can then put in two 100A breakers and make the two shorter runs to the HPWCs. So it doesn't save you quantity of breakers, but it can make for less total wiring cost, and can also make better use of the given capacity in your main panel. I hope I am explaining that correctly, as @FlasherZ described in the other thread about it.
I didn't realize the top entry bracket had a bottom entry, if so, that would help you. The top entry bracket would have to be listed as a junction box (I don't believe it is) and would have to have the appropriate volume in cubic inches to support 6 100-amp conductors plus 2 ground conductors and connectors. I'm unsure if it does or not.
Indeed the issue is that the terminal block on the bracket does not permit you to chain the next set of conductors to the next HPWC.
See here for my post detailing how you connect these HPWC's up:
What's up with HPWC?
CmdrThor
Active Member
Thanks for clearing this up .. Hopefully some people who have successfully installed their multiple Wall Connectors will post some pictures. I guess you have to use the same breaker size for all of your Wall connectors then since you don't specify the breaker size on the slave. I am planning on installing one Wall Connector soon and a second when Model 3 arrives. I'll need to think about whether I want to put in a subpanel now, or wait until I actually need it.
Correct.
It's always easier to provision now for the future... but if using exposed conduit, there's the option to pull the wiring out of the HPWC and use that to feed a subpanel directly in the wiring path later. The cost of a subpanel is not too much (~$70 or so) and the extra labor later to pull the wiring out of the HPWC and re-route to a subpanel may cost just as much. In addition, the subpanel can count as a readily-accessible disconnect required under article 625 if > 60A and your inspector requires it to be in the garage.
sowbug
Member
I just sent mail to my electrician, because I see very little on the exposed parts that would conclusively answer the question. Here's what I can see:
- 200A main with single 100A breaker marked "Tesla." This was here for the initial installation in 2014.
- Wall Connector #1 attached to the outside of my house (Eichler with garage converted to bedrooms, so we park in the driveway). No visible conduit. There is no mounting bracket on this connector.
- Conduit poking out of the roof above WC #1, running across the roof to the other side of the driveway, then down through a hole in the eave, down to Wall Connector #2. In other words, visible conduit to WC #2. This connector does use the mounting bracket.
Edit: got an answer quickly! From electrician:
I actually used the main panel as a splice box, which is a legal technique, and used insulated lugs (Polaris or Burndy lugs) which accept up to 3 wires per. One to the breaker, and one to each charger. We often use the same technique on certain solar installs where we need to tap into the main feeder wires of a panel.
I live in California, in case that's relevant to code discussion.
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