I would not recommend 4 gauge NM-B. Instead, use conduit (PVC or metal) and 6 gauge THHN individual wires, or use 6 gauge MC cable (like here or here).
More info: CarCharging.us
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
FAQ: Home Tesla charging infrastructure Q&A
- Thread starter FlasherZ
- Start date
More info: CarCharging.us
Thank you for the quick response. Looks like these are not sold in hd/lowes stores locally as mentioned in the carcharging.us link I guess. Also, we probably only need like 4-6 feet. So is this or this a decent alternative?
Edit - looks like the amazon link you posted is a wirenco product. So I could just directly buy from those guys by foot?
You're drawing some mistaken conclusions from this. Wall connector is irrelevant and has nothing to do with it. Wall connectors could be installed on 15A circuits--they have a setting for that.
The real point is simply how many amps is the circuit rating?
Does the wire meet that amp rating?
Yes or no?
That really is it.
The wire rating must be >= the circuit rating. And it is astounding how often this rule gets violated. People are trying to use a wire with a 55A rating and saying, "Huh. That should be good enough for a 60A circuit." NO! It isn't. Just pick what circuit level you want and then use wire that is AT LEAST that high a rating--not less than.
So you follow the right conditions as far as whether it's dry or wet, in wall or exposed, in conduit or not, whatever. Those are the factors to determine what type of thing to use. And then you just have to pick a gauge thickness of it that's high enough for the amp rating of the circuit.
Yes, and you only need 6/2 cable. And appropriate box connectors. And straps. And bushings. Links for these (except the straps) are in the CarCharging page. Buy more cable than you need, it always seems to need more than you think.
davenlei
Member
So I see there is the option to 'chain' multiple wall chargers together on the same circuit to charger more than one car at the same time. I was hoping that a single wall charger would have been designed by tesla to have two charging cables coming out of it so a person can charge two cars off of the same circuit and have the wall charger be smart and robust enough to load balance the charging from a single unit. Since more and more households are becoming multi-Tesla homes, I would think the demand for a single wall charger to multi-car charging system demand will grow since the multiple wall chargers daisy chained together solution is double the price for equipment and installation and some homes may not have adequate wall space for two units on the wall.
FWIW, we've never had an issue charging two at 32 amps simultaneously. It was fine when the service was 200 amps, but with the switch from gas to heat pump, the service is now 400 amps. Still no issue. If you need to charge faster due to TOU or really long commutes, then there is a use case for staggered charging.
davenlei
Member
Yea I was thinking for simplicity and cost for the consumer. Now that EV adoption is growing, there will be many two and three EV/Tesla households and having multiple wall chargers will be accepted but not preferred. If some charger manufacturer creates a 'multiple cable/plug' single wall charger to allow two vehicles to be load balanced charged on a shared single wall charger at the same time, I think a lot of people would prefer that over two daisy chained chargers on the same circuit which communicate.
I think there are good sensible reasons why Tesla doesn't do that.
The sharing of units accomplishes that function already, but it is simpler and cheaper for Tesla in not having to build and support inventory for multiple types of wall connectors when one type already does it. And what about three? Should they then also build a three cable one?
Double for the equipment, sure, but that's only, what? $450 now? Not that much. And some extra installation price, but not double, since there is so much overhead in getting an electrician to do the bid and drive to your house just for a job.
That sounds really unlikely, and wouldn't the far more common thing be that one single location on the wall can't reach the charging ports of two cars easily? The two wall connectors separately lets people put them in the convenient place for each car, instead of a location that is going to be annoying and inconvenient for at least one of the cars.
My WAG is that the cost would be about the same for either method. The two circuit two Wall Connector method also will give you a backup. The main cost of installation is just getting the electrician out there unless the run is exceptionally long. Although we've been successfully using 14-50s for many years, the regulations now plus the added cost of the Mobile Connector make the difference in price between a 14-50 install and a Wall Connector install minimal.
There are some J1772 EVSEs that do this. Here's one: Grizzl-E Duo – GRIZZL-E
In the future, these same manufacturers might release NACS connector versions.
davewill
Active Member
It's a lot less flexible to put the two EVSEs into one cabinet, and the ones I've seen cost easily as much as two wall connectors. The difference in the install price doesn't have to be huge. You install a small load center (approx $100) with two circuit breakers in it inside the garage, then run two circuits from there to the two wall connectors.
You also have the freedom of putting each of them in the most convenient spot instead of having to have a long cable stretched across the garage to reach one of the cars. Two wall connectors also works better in the event of an equipment failure. A dual unit breaking might leave you without charging at all, but if one of two wall connectors fails, you can always limp along with the other one until it gets fixed.
You also have the freedom of putting each of them in the most convenient spot instead of having to have a long cable stretched across the garage to reach one of the cars. Two wall connectors also works better in the event of an equipment failure. A dual unit breaking might leave you without charging at all, but if one of two wall connectors fails, you can always limp along with the other one until it gets fixed.
Last edited:
They are not “chargers”. The Wall Connector and Mobile Connector are “connectors.” The charger is built in to the vehicle. The EVSE “connector” is a glorified extension cord with as many safety features as practical. Ultimately it does nothing more than connect your EV to the AC power grid.
Thank you, Capt. Semantics.
Yeah, those are like if you say, "Let me put on my shoes before we head out to dinner." and then your friend sticks his nose in the air and condescendingly says, "Those AREN'T shoes; they are boots." You might be liable to tell that friend to F off and go to dinner without you.
This is why I call the UMC "UMC".
And why I call the HPWC "HPWC".
I will invariably slip and use the word "charger" instead of "connector" for that last initial if I try to expand the acronym. Bummer they're not pronounceable as acronyms.
"Charging station" still seems like one of those technical terms that needs a common-people name.
But I digress.
Long live NACS!
israndy
Supercharger Hunter
I normally would be on the side of Capt. Semantics, but in this case the post was about the device that you attach to charge the car, it didn't require any info about the smarts of the process or the electronics, so I would let that one slide too.
davenlei
Member
A lot of those responses make sense. I guess I was trying to think minimalist in doing more with less. Regarding having two wall connectors for two cars, can both those wall connectors be wires to the same circuit and that is where the wall units communicate with each other to load balance how much juice they take from that one circuit to not overload it? My problem is that I don't have enough breaker spots left on my electrical panel to add a second 240V circuit and would have to pay to have a daughter panel installed like an ugly wart on the side of the house and the high expense to do it.
MLXXXp
Member
Yes, you can provision them to tell them that they are on the same circuit. They will then communicate with each other over WiFi to share the available current on that circuit as necessary.
It definitely doesn't need to be on the outside of the house. The usual way to do this is just to run the one single line from your main panel into the garage, and put the subpanel there, on the inside wall in the garage. Then, you just run the two lines out of that short distances to the two sides of your garage. Since you're doing most of the distance into the garage with the single line, and then just splitting it in two for the short runs inside the garage, it shouldn't be that much of a cost hit.
Yes, that's what the sharing is meant for. So in my example above, you can run a 40A line to the garage subpanel. Then out of that, you run both lines as 40A, but with both wall connectors communicating, you tell them that the parent supply line is only 40A, so it won't run them both at full power at the same time and won't overload anything.
Pssst! Take a look at the 4-5 posts following this one, everybody:
teslamotorsclub.com
New Tesla Universal Wall Connector
Tesla has released a new Universal Wall Connector: https://shop.tesla.com/product/universal-wall-connector It costs $595, and starts shipping in October. It has an integrated J1772 adapter, essentially MagicDock for AC charging. It lists an interesting feature: Auto-sensing handle to open...
teslamotorsclub.com
Similar threads
