Home Charging System / Charger Kit

[CyberG]

I have an opportunity to pick up a new/unused Gen 2 charger to add to my NEMA plug in system for my wife's Model 3 Long Range.
Is it a good idea and will work for the CT?

The Model 3 won’t be able to take advantage of all 80 amps, but like the other guy said, it’s easier to add additional gen 2 chargers because you can put up to 4 on one circuit. If multiple cars are charging it will even out the amps, for instance if you have 2 cars charging at the same time, each will get 40 amps. The model 3, and all current Teslas are limited to 48 amps. My classic Model S can go up to 80 amps.

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[Old Pro]

The Model 3 won’t be able to take advantage of all 80 amps, but like the other guy said, it’s easier to add additional gen 2 chargers because you can put up to 4 on one circuit. If multiple cars are charging it will even out the amps, for instance if you have 2 cars charging at the same time, each will get 40 amps. The model 3, and all current Teslas are limited to 48 amps. My classic Model S can go up to 80 amps.

Thanks. Information helps with CT on order. Not like I'll be able to fit both into my garage!

 

[CyberG]

Thanks. Information helps with CT on order. Not like I'll be able to fit both into my garage!

Forgot to mention that we don’t know yet whether the CT will go back to the old dual 40 amp configuration. It seems for the 500 mile range version it would be helpful to be able to charge at 80 amps.

 

[ajdelange]

I have an opportunity to pick up a new/unused Gen 2 charger to add to my NEMA plug in system for my wife's Model 3 Long Range.
Is it a good idea and will work for the CT?

The problem is that there are so many things you can do that will work that there is no best solution.

We won't know whether either a Gen 2 or Gen 3 will work with a CT or not until we see a CT but it is extremely probable that it will. Tesla (and other) manufacturers seem to have settled on 24 A charger modules. Thus gives them lots of flexibility. Put in 2 and you have 48 A total which, as a continuous load, requires a 60 A circuit, which is the largest circuit NEC allows for EVSE without installation of a separate lockable disconnect. If you have 3 ø mains you can use 3 modules for 72A effective rate (note that the X and 3 used to have a 3 module option even here in biphase Norh America). A 60 A circuit puts almost 11 kW (0.95*48*240) into the battery for at least 22 mi/hr added range in vehicles with consumptions as high as 500 Wh/mi. I'm guessing the Trimotor CT will have rated consumption of 350 - 400 Wh/hr meaning 27.5 - 31.5 added miles per hour charging. But the TriMotor will be a 500 mi range vehicle with a battery about twice the size of what's in an X and if I were sitting around the conference table with Elon and the guys I'd say "Hey, why don't we split this battery into two parts and hook a separate charge port with a 2 module charger to each just as we are doing with the Semi?" They might all throw their coffee cups at me and laugh me out of the room but given that this is apparently what they are doing with the Semi it seems reasonable to consider for the CT. It would allow the residential user with two HPWC on 60 A circuits to charge at double the rates given above, halve charging time at whatever SC the Semi will be using and even allow 800 V charging should Tesla decide to go that route some day.

Were this fantasy of mine to prove to be the case and you wanted to take advantage of it or if you contemplate having any two moderns Tesla vehicles that you thought you might want to simultaneously charge at the maximum rate then the way to go is to install two Gen 3 HPWC each on its own 60 A or smaller circuit. Those circuits can both originate in a sub panel if it is easier to pull two sets of No. 6 than a single set of No. 1 (which it is - bigger than No. 6 I call an electrician). The total charging draw will be controllable with future software/firmware (downloadable over the WiFi connection) so you could go with a 100 subpanel, for example, and have a total of 80A charging, if you wanted.

I'm not sure what you mean by "NEMA plug in system". I assume that there is a NEMA 14-50R and that it is on a 50A circuit (but these can legally be installed on 40 A circuits too and you sometimes find this in older houses). What I am uncertain about is whether the "plug in" part refers to the UMC that comes with the car, to the HPWC with a plug that Tesla sold up to a about a year ago or a third party (ChargePoint, Wattzilla....) charger with a plug. While technically the Tesla plugin HPWC could be shared (as it is just a regular Gen 2 HPWC with the dial set to 50A and a smaller cord going to the car) with another Gen 2 I would definitely not recommend doing that as I can't see a way to get it past an inspector.
Overall I guess I see no advantage to picking up an old Gen 2 HPWC unless you already have one or more Gen 2(s) installed on a 100 A circuit. Should you want to load share with the existing NEMA plug in system I guess I'd replace that, whatever it is, with a Gen 3 HPWC and then install another Gen 3 wherever is convenient. The only requirement for load sharing is that multiple 3's be on the same WiFi net.

Load is something to think about. I saw a YouTube video yesterday in which a guy blythely installed a 48A load (Gen 3) on a panel in a 125 A service. While it was pretty clear that no inspector was ever going to see this the danger is that an insurance company claims adjuster might some day be looking at it. So my advice is always the same: get an electrician who knows EVSE and the local inspectors involved.

 

[CyberG]

The problem is that there are so many things you can do that will work that there is no best solution.

We won't know whether either a Gen 2 or Gen 3 will work with a CT or not until we see a CT but it is extremely probable that it will. Tesla (and other) manufacturers seem to have settled on 24 A charger modules. Thus gives them lots of flexibility. Put in 2 and you have 48 A total which, as a continuous load, requires a 60 A circuit, which is the largest circuit NEC allows for EVSE without installation of a separate lockable disconnect. If you have 3 ø mains you can use 3 modules for 72A effective rate (note that the X and 3 used to have a 3 module option even here in biphase Norh America). A 60 A circuit puts almost 11 kW (0.95*48*240) into the battery for at least 22 mi/hr added range in vehicles with consumptions as high as 500 Wh/mi. I'm guessing the Trimotor CT will have rated consumption of 350 - 400 Wh/hr meaning 27.5 - 31.5 added miles per hour charging. But the TriMotor will be a 500 mi range vehicle with a battery about twice the size of what's in an X and if I were sitting around the conference table with Elon and the guys I'd say "Hey, why don't we split this battery into two parts and hook a separate charge port with a 2 module charger to each just as we are doing with the Semi?" They might all throw their coffee cups at me and laugh me out of the room but given that this is apparently what they are doing with the Semi it seems reasonable to consider for the CT. It would allow the residential user with two HPWC on 60 A circuits to charge at double the rates given above, halve charging time at whatever SC the Semi will be using and even allow 800 V charging should Tesla decide to go that route some day.

Were this fantasy of mine to prove to be the case and you wanted to take advantage of it or if you contemplate having any two moderns Tesla vehicles that you thought you might want to simultaneously charge at the maximum rate then the way to go is to install two Gen 3 HPWC each on its own 60 A or smaller circuit. Those circuits can both originate in a sub panel if it is easier to pull two sets of No. 6 than a single set of No. 1 (which it is - bigger than No. 6 I call an electrician). The total charging draw will be controllable with future software/firmware (downloadable over the WiFi connection) so you could go with a 100 subpanel, for example, and have a total of 80A charging, if you wanted.

I'm not sure what you mean by "NEMA plug in system". I assume that there is a NEMA 14-50R and that it is on a 50A circuit (but these can legally be installed on 40 A circuits too and you sometimes find this in older houses). What I am uncertain about is whether the "plug in" part refers to the UMC that comes with the car, to the HPWC with a plug that Tesla sold up to a about a year ago or a third party (ChargePoint, Wattzilla....) charger with a plug. While technically the Tesla plugin HPWC could be shared (as it is just a regular Gen 2 HPWC with the dial set to 50A and a smaller cord going to the car) with another Gen 2 I would definitely not recommend doing that as I can't see a way to get it past an inspector.
Overall I guess I see no advantage to picking up an old Gen 2 HPWC unless you already have one or more Gen 2(s) installed on a 100 A circuit. Should you want to load share with the existing NEMA plug in system I guess I'd replace that, whatever it is, with a Gen 3 HPWC and then install another Gen 3 wherever is convenient. The only requirement for load sharing is that multiple 3's be on the same WiFi net.

Load is something to think about. I saw a YouTube video yesterday in which a guy blythely installed a 48A load (Gen 3) on a panel in a 125 A service. While it was pretty clear that no inspector was ever going to see this the danger is that an insurance company claims adjuster might some day be looking at it. So my advice is always the same: get an electrician who knows EVSE and the local inspectors involved.

I’m sure you’re right, if anything the CT would have 3 24amp modules. Would that require a 100 amp lead and a Gen 2 charger? That may be why Tesla has recently reintroduced the Gen 2. I suspect the roadster would also be equipped with 3 charging modules since it will have around 620 miles of range, thus a big battery pack.

 

[ajdelange]

CT's sold in the European markets will have 3 24A modules, one for each phase - presumably based on what they are doing now and the direction the Gen 3 charger idicates they are moving in. You used to be able to order the X (and I think the 3) with a "fast charging" option (I think it was called something like that (3) 24 A modules) but they have stopped making that option available and doubt they will return to it (in biphase markets). But were they to go back to 3 modules of 24 A each that would total 72 A 125% of which is 90A so a 90A breaker and circuit would be adequate for charging such a car. The Gen 2 was designed to handle the old S with dual 40 A chargers; total load 80 A for a breaker/wire requirement of 100A. That is the highest breaker position selectable in commissioning a Gen 2 HPWC.

With the Gen 3 the largest circuit size is 60 A supporting 48 A charging in the car/truck per HPWC and thus per port. Thus the CT would not have 3 24A modules, as did the old X, connected to a single port as the HPWC they are selling now would not support it. If they want to support more than 48A of charging they will have to install a separate port which would handle 2 more 24A modules. This is, at the rumor level, what they are planning for the Semi so I am guessing that they will do this for the CT and probably the Roadster too. But this is all based on common sense reasoning, I do not own a functioning crystal ball.

 

[ajdelange]

That may be why Tesla has recently reintroduced the Gen 2.

The Gen 2 has been temporarily reintroduced to accomodate those of us who already have one or more Gen 2 HPWC and wish to add additional charging stations with load sharing. That cannot be done with Gen 3 stations.

As an example: I originally installed a Gen 2 HPWC on a 100 A circuit. I had a 72 A X. I have since traded it in for a Raven so I can now charge no faster than 48 A and I have ordered a CT and a R1T so I need another charger and I don't want to pull another circuit. The Gen 2 is no longer available. How can I use the charger I have and share the circuit with a second? Answer: I can't. I would have to remove the Gen 2, install a sub panel with two 50 A breakers and order two new Gen 3 each set for 50 A breakers. I could then charge two EVs at a maximum of 40 A each. This means a maximum load of 80 A on the subpanel such that it meets the 80% derating requirement. Maybe that's an overly cautious interpretation of the code. Two 60 A breakers might be allowed. If one car completes first, I can only send 40 A to the remaining. But Tesla hears lots of squealing from guys like me and so decides to make the Gen 2 available again for a while. Now all I have to do is run wire from the disconnect to a second location (but it has to be No 3 as I could, potentially plug an 80 A Model 3 into it some day) and install the second Gen 2. I can now charge two cars at up to 40 A but when the first finishes the remaining goes up to 48 A (or if it is an X with triple modules, 72A). Though pulling No. 3 is not something I much enjoy doing it is a lot easier than having to install a subpanel and I get a bit more capacity

 

[TyPope]

Do the Gen 3 chargers communicate with each other? If I have a line installed to my garage from a 60A breaker, would I be able to install two Gen 3 chargers and have them never go above a combined 60A?

I'd probably have an electrician put in a sub-panel so I could add a 20A outlet or two that I could use when I don't have a car charging.

 

[ajdelange]

At the moment, no, but they will. The WiFi software is not complete. When it is finished it will evidently be quite flexible. Yes, you will be able to limit total draw by Gen 3 chargers wherever they are as long as they are on the same WiFi network.

 

[TyPope]

At the moment, no, but they will. The WiFi software is not complete. When it is finished it will evidently be quite flexible. Yes, you will be able to limit total draw by Gen 3 chargers wherever they are as long as they are on the same WiFi network.

Okay. Thanks. That makes sense. Of course, I can set them up to limit their draw when I install them as well but then they don't share, they are just limited. Not quite the same but effective all the same.

 

[Bigvbear]

I was kinda wondering this myself. I do not currently own a Tesla vehicle (The CT will be my first) and been thinking about home charging. I will most likely opt for the HPWC unit and the Gen 3 just came out.

Since it's still a few years before the CT hits the streets, will they have a Gen 4 charger by then? Also, since we have no idea what the CT will charge at (yet) is it just best to wait until further specs are available?

i am quite fortunate that where my electrical panel is the installation will be quite simple as its just on the other side of the wall from where the CT will be parked and charged, so the electrical run will be quite short (maybe 2') so that cost should be minimal.

 

[ajdelange]

Since you have no need for a home charging solution at this point clearly your best option is to wait until delivery or even defer to post delivery to see how the thing works. The guys with the head scratching to do are those who already have something in place, want to upgrade now (because they have another Tesla or other BEV on order) and want to be able to retain the value of their current charging investment.

We do, in fact, have a pretty good idea of what the CT charging will be. It will be, for the rear and dual options, 11.5 kW. For the TriMotor it will be at minimum 11.5 kW or possibly 23 kW from the inclusion of an (optional) second charge port.

 

[Bill906]

Typically a 200 A panel (which is 400 phase amps as I like to call them as there are two phases)

1. You can only get 200A from a 200A system. Please think this through. If you still think you can get 400A from a 200A service please explain. It will be easier to explain it to you when I know what part is causing the confusion.

2. Although someone could argue a center tapped winding creates two phases 180° apart, I believe doing that only causes confusion. If you have three points that create a straight line is it one line, or two lines 180° from each other? The two main benefits of multi-phase power is A) Allows for simplified induction motor use. B) Less conductor material required for the same amount of power in power transmission lines. There are other advantages like reducing harmonics from nonlinear loads but that goes beyond the scope of this discussion. Two phases 180° apart does not give us any of those benefits. Instead of calling it a 2-phase system I believe the more popular term, split-phase, is more correct and less confusing.

This is my first time quoting someone. I hope I did it right.

 

[ajdelange]

1. You can only get 200A from a 200A system. Please think this through. If you still think you can get 400A from a 200A service please explain. It will be easier to explain it to you when I know what part is causing the confusion.

Yes, but that's 200 A per phase. If I have a generator that delivers 1 kW for 2 hours that's 2 kW-hours of energy. If I have a 1 pound weight and I raise it two feet from the floor to the table top I have done 2 foot-pounds of work on it. If I have a panel with two phases each of which delivers 200 A that totals 400 phase-amperes of service. Is that so hard to understand?

2. Although someone could argue a center tapped winding creates two phases 180° apart, I believe doing that only causes confusion. If you have three points that create a straight line is it one line, or two lines 180° from each other?

Note that I didn't argue that. I just said my panel's capacity is 400 phase amps. But as you have brought this up I'll point out that engineers like to simplify things so that they can do their calculations more easily. In general an electrical system involves a number of phases that carry currents in specified relations to one another. Tesla's (Nikkola, not Elon) original motor involved 2 phases 90 ° apart but he wound (no pun intended) up with three 120 ° apart. Obviously a split phase system is simply a biphase one with the separation between the phases being 180 °. Thus it is convenient to think of it within the polyphase architecture if you are an engineer or scientist but it doubtless would be confusing to a lay person. But how do you know that the phases in the panel I am talking about are 180° apart? They could be 120 ° though of course in the typical North American residential situation they are 180° but not all panels that get HPWC get connected to them are 180 °.

The two main benefits of multi-phase power is A) Allows...

Note that I never said anything about polyphase systems in my post. I just said that my 200 A panel has service capacity of 400 phase - amperes or, more specifically I said that I like to refer to it as 400 phase amps. Perhaps I could have said 400 stab amps or 400 bus amps or 400 pole amps but with my background I just use phase amps and my electicians have no problem with understanding that as while they may not be up on the electrical engineering principles behind what they do they can understand that when I say "That panel has 750 øA of breakers in it" that means that the sum of the little numbers on the breakers is 750.

Note also that the total service or total load is easily computed my multiplying øA by V/ø. The øA notation just makes the computation of loads much clearer (to my mind anyway).

This is my first time quoting someone. I hope I did it right.

Yes, you did and thanks for taking the time to do it this way, There are lot's here who when they want to respond to a single line in a lengthy post quote the whole thing which wastes bandwidth and makes it harder to figure out what in particular they are responding to.

 

[TyPope]

I suppose I don't know how to quote only part of a post. Do you just hit "reply" and then cut the parts you don't want to keep?

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