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What rating did you do to wire your HPWC, and should you future-proof?

Tube Guy

Member
Jan 2, 2019
63
17
So Cal
Greetings

I have a 2016 X P90D, and I bought a Gen II HPWC from a guy that was manufactured Jan 2019. I'm about to have it installed by running a dedicated line to it.

Any suggestions on the cable and breaker?

I'm having three other lines installed into other locations for future use as well as being used with my mobile charger. Love any input on that too. I want to be ready for what comes down the pipe.

Thanks!
 

Tessaract

Member
Aug 12, 2019
337
338
Ottawa
Greetings

I have a 2016 X P90D, and I bought a Gen II HPWC from a guy that was manufactured Jan 2019. I'm about to have it installed by running a dedicated line to it.

Any suggestions on the cable and breaker?

I'm having three other lines installed into other locations for future use as well as being used with my mobile charger. Love any input on that too. I want to be ready for what comes down the pipe.

Thanks!
Realistically, anything more than a 60A breaker (which results in 48A/ 11.5kW actually delivered to your car) is overkill, in my opinion. Here in Ontario, a 60 A circuit requires 6 AWG cable. Even a 40A breaker (32A/7.7 kW delivered) will fully charge a 75kWh battery from completely empty in 10 hours overnight. In Ontario, a 40A circuit requires 8 AWG cable.
 
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Rocky_H

Well-Known Member
Feb 19, 2015
6,770
8,360
Boise, ID
Realistically, anything more than a 60A breaker (which results in 48A/ 11.5kW actually delivered to your car) is overkill, in my opinion. Here in Ontario, a 60 A circuit requires 6 AWG cable. Even a 40A breaker (32A/7.7 kW delivered) will fully charge a 75kWh battery from completely empty in 10 hours overnight. In Ontario, a 40A circuit requires 8 AWG cable.
By the way, be careful on your wording here. The word "cable" means wires bundled together in a rubber sheath, also usually called Romex. 6 gauge Romex cable is not rated to be used for a 60A circuit. 6 gauge separate wires run in conduit is rated for a 60A circuit.
 
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Rockster

Active Member
Oct 22, 2013
3,014
4,692
McKinney, TX
IMO, the HPWC should be wired with the maximum amperage that your home's electrical infrastructure can support. This will allow you to charge at the max possible rate, no matter the Tesla being charged, and also support daisy chaining multiple units, should the need arise (e.g., you eventually own multiple Teslas).

This is the approach I took. I have two HPWC's daisy chained on a 100 amp circuit. While we typically charge at a relatively low amperage, our Model S can charge at 80 amps, which is occasionally necessary if we've been out running around all day and want to return home and charge over dinnertime for a fast turnaround to head out of town that evening for the weekend. Normally, the S and the 3 charge at 30 or 40 amps, since we're not usually in a rush.

This way, you future proof the installation and will never have any regrets about not having an expandable charging system.

My system splits the 100 amp line using a mutl-tap connector, as shown:

Wall chargers_wall open.jpg
 

Tessaract

Member
Aug 12, 2019
337
338
Ottawa
By the way, be careful on your wording here. The word "cable" means wires bundled together in a rubber sheath, also usually called Romex. 6 gauge Romex cable is not rated to be used for a 60A circuit. 6 gauge separate wires run in conduit is rated for a 60A circuit.
My cable sizes are accurate for Ontario. Including 6 AWG Romex (actually called NMD-90 if we're aiming for accuracy), 6AWG TECK, etc. And any assembly of 2 or more conductors is a cable. Doesn't need to be a rubber sheath.
 
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Steinmetz

Maker of Lightning
Sep 25, 2019
89
40
Penngrove California
First off, I'm a newbie here so others may have more sage advice....

I am in the process of installing my Wall Connector. I am putting it on an 80 Amp circuit, because there is an advisory on page 5 of the specs that came with it "The maximum power rating for the Wall Connector is 20kW or 80 Amps at 250 VAC single phase power." My new X is limited to 48 Amp charging rate, which to do that a 60 Amp circuit would be required. Since I am running in the new circuit the incremental cost of making it an 80 Amp circuit is reasonable in my mind, especially since my wire run is only about 35 feet. I believe earlier Tesla models were capable of charging at a higher rate, not limited to 48 Amps.

The current generation wall connector can be fitted with adapters, which can give you up to a 32 Amp output. The electrical receptacle required must be capable of 50 Amps, and it seems most terminate in a NEMA 14-50 receptacle. Again this would require a 50 Amp circuit.

The type of cable or wire size will depend on your installation. Different gauge will be required if it is cable, such as Romex, or conduit with THWN wire in it. If the run is very long you may need to 'upsize" the conductors.

You mention installing three other lines. Will these be in concurrent use? If so there may be an issue with incoming service, since I assume you have a residential 200 Amp service.
 

Steinmetz

Maker of Lightning
Sep 25, 2019
89
40
Penngrove California
Since I see there was a proper discussion of cable versus wire, just to add another layer, at least in the US, a flexible, rubber sheath group of wires is called "cord", or "cordage". What you plug into your car is a cord as far as the National Electrical Code is concerned. Cordage is not intended for any permanent application.
 
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Rocky_H

Well-Known Member
Feb 19, 2015
6,770
8,360
Boise, ID
My cable sizes are accurate for Ontario. Including 6 AWG Romex (actually called NMD-90 if we're aiming for accuracy), 6AWG TECK, etc. And any assembly of 2 or more conductors is a cable. Doesn't need to be a rubber sheath.
Since you were nitpicking on what the material of the sheath is, I thought you missed my point completely.

I've been trying to Google for it, but I can't find that CEC has a different ampacity table for wire and cable than the NEC uses. Does Canadian electric code have a different amp rating chart? In the one used by NEC, NM-B cable has to use the 60 degree C rating, and is only allowed for 55 amps, so it cannot be used for a 60A circuit. I thought the CEC and NEC were synced on that.

Can you find a link to the CEC ampacity chart then? I couldn't come up with one.
 

Tube Guy

Member
Jan 2, 2019
63
17
So Cal
IMO, the HPWC should be wired with the maximum amperage that your home's electrical infrastructure can support. This will allow you to charge at the max possible rate, no matter the Tesla being charged, and also support daisy chaining multiple units, should the need arise (e.g., you eventually own multiple Teslas).

This is the approach I took. I have two HPWC's daisy chained on a 100 amp circuit. While we typically charge at a relatively low amperage, our Model S can charge at 80 amps, which is occasionally necessary if we've been out running around all day and want to return home and charge over dinnertime for a fast turnaround to head out of town that evening for the weekend. Normally, the S and the 3 charge at 30 or 40 amps, since we're not usually in a rush.

This way, you future proof the installation and will never have any regrets about not having an expandable charging system.

My system splits the 100 amp line using a mutl-tap connector, as shown:

View attachment 468493

Thanks for responding. My electrician speaks little English. I think I will follow your lead as I will run a 100 amp line, put the HPWC inside my garage and a 14-50 socket outside on the same line (Imay be parking the car outside at times).

I'm adding 2 more taps to the side walls for the future. Should I run a 100 amp line to those too? Using a 14-50 socket?
 

Lloyd

Well-Known Member
Supporting Member
Jan 12, 2011
6,334
2,200
San Luis Obispo, CA
IMO, the HPWC should be wired with the maximum amperage that your home's electrical infrastructure can support. This will allow you to charge at the max possible rate, no matter the Tesla being charged, and also support daisy chaining multiple units, should the need arise (e.g., you eventually own multiple Teslas).

This is the approach I took. I have two HPWC's daisy chained on a 100 amp circuit. While we typically charge at a relatively low amperage, our Model S can charge at 80 amps, which is occasionally necessary if we've been out running around all day and want to return home and charge over dinnertime for a fast turnaround to head out of town that evening for the weekend. Normally, the S and the 3 charge at 30 or 40 amps, since we're not usually in a rush.

This way, you future proof the installation and will never have any regrets about not having an expandable charging system.

My system splits the 100 amp line using a mutl-tap connector, as shown:

View attachment 468493

Looks like #6 wire which is not sufficient for a 100 amp breaker. #3 is minimum for 100 amps at the breaker.
 

Rocky_H

Well-Known Member
Feb 19, 2015
6,770
8,360
Boise, ID
I think I will follow your lead as I will run a 100 amp line, put the HPWC inside my garage and a 14-50 socket outside on the same line
Then that would not be following his lead. Please don't do that. What @Rockster showed was doing two wall connectors on a 100A circuit. That is fine--those are 100A rated appliances, and they are built for smart current sharing on the same circuit. What you cannot do is put a 50A rated outlet on a 100A circuit.

I'm adding 2 more taps to the side walls for the future. Should I run a 100 amp line to those too? Using a 14-50 socket?
Again: you cannot put a 50A outlet on a 100A circuit, ever. Code is really specific that the circuit breaker cannot be higher rated than the outlet. It is allowed to go lower, though, so you could do 40A circuits, although I just don't think that's the better way to go. So if you want to add other 14-50 outlets, you need to run 50 or 40 amp breakers/wiring.
 

Rocky_H

Well-Known Member
Feb 19, 2015
6,770
8,360
Boise, ID
One more thing PLEASE if somebody can answer is there a superior outdoor weatherproof outlet I should buy?
The receptacle itself isn't really the part that would be indoor or outdoor. I would recommend something like Hubbel or Cooper, though. Just not Leviton.
But for the outdoor part, it's what kind of box you use to install the receptacle in. There are lots of kinds of outdoor outlet boxes if you Google for it. Here's an example:
https://www.amazon.com/dp/B0756K2CY...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=
 

Rockster

Active Member
Oct 22, 2013
3,014
4,692
McKinney, TX
Looks like #6 wire which is not sufficient for a 100 amp breaker. #3 is minimum for 100 amps at the breaker.

It's #3 wire. Not sure why it looks like #6. I wanted to use #2 but the distance was so short and the difficulty with the 90-degree bend with a rear entry into the unit made it not worth using #2.
 

Tube Guy

Member
Jan 2, 2019
63
17
So Cal
I have only one HPWC. And adding three more outlets to other spots for convenience and the future. Can I run #3 to a 14-50 outlet and change that later to whatever the current HPWC is at that time? Use a 60 amp breaker for now and change it later?

I really appreciate the help guys and gals. TRULY.
 

Hebert

MXLR, RN1153, 7/20, Blue/Black/5/20", EDD Jan
Apr 28, 2019
149
136
Peoria, AZ
Yes, you could use 3 gauge wire for a new dedicated circuit with a 14-50 outlet. The outlet is only rated at 50 amps so the circuit breaker would need to be 50 amps well. This circuit could be used for up to a 40 amp continuous draw.

Make sure your electrician calculates the loads on your panel to see if you have capacity there.

Then later you could rewire to an HPWC and set it to 40 amps, or potentially more if your panel loads allow.
 

Tube Guy

Member
Jan 2, 2019
63
17
So Cal
Yes, you could use 3 gauge wire for a new dedicated circuit with a 14-50 outlet. The outlet is only rated at 50 amps so the circuit breaker would need to be 50 amps well. This circuit could be used for up to a 40 amp continuous draw.

Make sure your electrician calculates the loads on your panel to see if you have capacity there.

Then later you could rewire to an HPWC and set it to 40 amps, or potentially more if your panel loads allow.

Thanks Herbert! If I take the outlet out and get more HPWC, simply change the breaker. Sounds like a good move.
 

Rocky_H

Well-Known Member
Feb 19, 2015
6,770
8,360
Boise, ID
Can I run #3 to a 14-50 outlet and change that later to whatever the current HPWC is at that time?
Yes, you could use 3 gauge wire for a new dedicated circuit with a 14-50 outlet.
Well, that's a tricky one and may depend on what brand of 14-50 outlet you are using. It is certainly fine by electric code to use oversized wire, but in the specifications for most outlets, they list a maximum wire gauge thickness that can fit in their terminals. I've seen on at least one 14-50 outlet type, that it says max 6 gauge. So, you may need to use some kind of intermediate polaris connectors or junction box or something near the end where the outlet is to switch down from 3 gauge to 6 gauge.

This can be where you hit a nice sweet spot. If you do 6 gauge wire in conduit, that is properly rated for a 60A circuit, so you could switch to a wall connector later and get 48A, but that gauge will always fit a 14-50 outlet on a 50A circuit.
 

ditzpro

Member
Jul 8, 2016
108
33
michigan
Not an electric guy so question ..Where is the ground wire to the hpwc on the left side ..Am I just not seeing it ?
Received my hpwc but not installed yet ...
Thanks
 

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