Wiring for Tesla Charger, Powershare

[mongo]

The control wire is required because the Gateway needs to talk with the WC directly. On mine they had to pull the wires out (in conduit under my driveway because the WC is on the other side) and then run them back with the control wire.

all (modern) Teslas max out at 48 amps on a 240v circuit and a 60-amp breaker. If your wire is suited right for a 240v/60-a service you are fine. The control wire is separate.

Yeah, but the description doesn't sound like the communication wire. That would be from the Gateway, not the circuit breaker. Could be a miscommunication though.

but the electrician is saying that they’ll need to also run a new wire from the circuit breaker to the wall connnector.

If it's only a partial home backup, the UWC circuit needs to move to the Gateway (or down stream).
If it's whole house, the existing connection should be fine.

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[eswimm]

Prior to Powershare installation, I had 2 Gen 2 wall connectors installed. One wired with 6 AWG Cu THHN in conduit, the other with 3 AWG Al NM-B to a 60A disconnect and 4 AWG Cu MC from the disconnect to the wall connector. The 2nd run was ~75', so aluminum was a lot cheaper, but the HPWC isn't rated for aluminum conductors, so added the disconnect rated for Al/Cu right next to the wall connector to minimize the copper.

Powershare installer reviewed both installs and either was acceptable and the quote included a charge to replace an existing EVSE and reuse wiring. It did need a communication wire run, since the existing wall connector didn't use one.

Powershare was activated a few days after install, I opted for full panel backup (main breaker separation) for one of my 200A panels. It worked fine during a manual test (trip the 200A main breaker installed in the gateway) and during a 6h outage when a distracted driver took out a utility pole and ~1400 houses' power.

I don't have solar or Powerwall however, I know some of those users are still waiting on support.

EDIT: They did move the 3 AWG Al wire from my panel to the gateway (with a new 60A breaker). The placement of the gateway was intentional so there'd be enough slack to move the wire from the other panel (the 200A that was not being backed up) to the gateway. Had it been in the panel being backed up, I believe it could have stayed where it was.

 

[EWELON]

So “control wire” would be a new wire nowhere near the size/price of the pictured existing wire running from the circuit breaker to the existing first gen WC. Correct?

This control wire would enable communication from the new universal wall connector and the PowerShare gateway. (I’m only getting a partial backup install of a few circuits)

So I need a new run of 20 feet of #22 ga communication wire, NOT a new run of 20 feet of 4 AWG $1000 wire? Correct?

 

[mongo]

So “control wire” would be a new wire nowhere near the size/price of the pictured existing wire running from the circuit breaker to the existing first gen WC. Correct?

This control wire would enable communication from the new universal wall connector and the PowerShare gateway. (I’m only getting a partial backup install of a few circuits)

So I need a new run of 20 feet of #22 ga communication wire, NOT a new run of 20 feet of 4 AWG $1000 wire? Correct?

If the partial backup is from the Gateway or a subpanel the wall connector isn't currently fed from, the branch circuit will need relocated there.
20 feet of 3x4AWG 1x6AWG SER is only $200.
https://www.wireandcableyourway.com/ser-cable

Comms wire is much smaller gauge with twisted pair for the RS485.

 

[CyberGus]

What about group power management on separate branch circuits?

AFAIK, the Group Power Management feature of the UWC is accomplished via WiFi. The grouped UWCs have no idea where the power is coming from.

That said, my UWC was wired through a 2" EMT conduit, and the installers refused to run another pair of wires for a 2nd UWC because the conduit amperage was "at capacity". I tried to explain the Group Power Management but they insisted that NEC code did not allow more wires in the conduit, even though they would not be used simultaneously.

 

[btcrealm]

Based on what people have said and what the wire looks like it says. You have 8AWG, the only think I can think of on the power side is distance. If its extremely long you might need 6AWG but I can't see any reason for 4AWG.
Personally this is what I used SIMpull 500-Feet 6 -AWG Orange Stranded Copper THHN wire ( By-the-roll ). I just bought a roll of it, and a roll of 8AWG grounding wire to go with it.

 

[mongo]

Based on what people have said and what the wire looks like it says. You have 8AWG, the only think I can think of on the power side is distance. If its extremely long you might need 6AWG but I can't see any reason for 4AWG.
Personally this is what I used SIMpull 500-Feet 6 -AWG Orange Stranded Copper THHN wire ( By-the-roll ). I just bought a roll of it, and a roll of 8AWG grounding wire to go with it.

They have 4AWG now, only the ground in it is 8.
NM-B requires the use of the 60 degree rating. So to get 60A (48A continuous) requires 4 AWG. 6 in NM-B is only rated for 55 Amps.

Copper THHN at the 75C column would only need 6 AWG. 8 AWG is too small for the phase conductors.
https://www.cerrowire.com/wp-content/uploads/2021/04/Cerrowire_Ampacity_Chart_210405.pdf

 

[eswimm]

So “control wire” would be a new wire nowhere near the size/price of the pictured existing wire running from the circuit breaker to the existing first gen WC. Correct?

This control wire would enable communication from the new universal wall connector and the PowerShare gateway. (I’m only getting a partial backup install of a few circuits)

So I need a new run of 20 feet of #22 ga communication wire, NOT a new run of 20 feet of 4 AWG $1000 wire? Correct?

Yeah, the comms wire is 16-24 AWG, 4 conductor (2 twisted pairs), shielded wire. Nothing too fancy, but it's not going to be the unshielded wire used for doorbells, door/window sensors or thermostats.

 

[smcnaughton829]

As others have said your current wiring for your WC will work for your UWC.
The comm wire also is correct, I have a 22 gauge 4 wire running to my UWC.
I have a FULL panel backup using the PowerShare.
Also Group Power Management is NOT possible while using PowerShare. I am not saying you can’t put it on your other WC, but PowerShare will not work if you have your UWC setup in the group power management system.
I have 3 WC, one being the UWC. My to WX are setup in group power management, while my UWC is just set for standalone.
ALL 3 wall connectors are using the same 60amp breaker going to a sub panel where each has their own 60 amp breaker for full power when running by its self.
The only issue is I can not charge my Truck using the UWC while any of my other cars are charging the other WC as it will trip the breaker. So I have schedule charging for my other cars using the group power management. Yes it sounds complicated but it isn’t.
Now to your PowerShare and powerwall. No you can not use this setup yet. Tesla still is waiting for an update. Just like I waited 6 months after my PowerShare install to get it working because I have solar.
Photo is before he installed the 3rd breaker for the UWC.

 

[mongo]

As others have said your current wiring for your WC will work for your UWC.
The comm wire also is correct, I have a 22 gauge 4 wire running to my UWC.
I have a FULL panel backup using the PowerShare.
Also Group Power Management is NOT possible while using PowerShare. I am not saying you can’t put it on your other WC, but PowerShare will not work if you have your UWC setup in the group power management system.
I have 3 WC, one being the UWC. My to WX are setup in group power management, while my UWC is just set for standalone.
ALL 3 wall connectors are using the same 60amp breaker going to a sub panel where each has their own 60 amp breaker for full power when running by its self.
The only issue is I can not charge my Truck using the UWC while any of my other cars are charging the other WC as it will trip the breaker. So I have schedule charging for my other cars using the group power management. Yes it sounds complicated but it isn’t.
Now to your PowerShare and powerwall. No you can not use this setup yet. Tesla still is waiting for an update. Just like I waited 6 months after my PowerShare install to get it working because I have solar.
Photo is before he installed the 3rd breaker for the UWC.

Cough *conduit* cough ?

 

[EWELON]

due to our driveway situation and the sheer size of the CT im probably now just going to add a second UWC to my install.

weird thing is now that last night the breaker for my WC tripped last night. while my CT was charging. ive been charging without issue with it for the week that ive owned it, and for 5 years with our model 3. hopefully this was just a fluke but is this a sign of anything?

 

[BrockN]

due to our driveway situation and the sheer size of the CT im probably now just going to add a second UWC to my install.

weird thing is now that last night the breaker for my WC tripped last night. while my CT was charging. ive been charging without issue with it for the week that ive owned it, and for 5 years with our model 3. hopefully this was just a fluke but is this a sign of anything?

If it happens regularly, the breaker could be getting soft and that would mean replacement.

 

[EWELON]

If it happens regularly, the breaker could be getting soft and that would mean replacement.

good to know. not regularly…..yet. last night was the first instance.

 

[BrockN]

good to know. not regularly…..yet. last night was the first instance.

All you can do for now is keep an eye on it. Perhaps check to see if the panel is getting strangely warm at that breaker too...

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