The onboard MS charger has a max capacity of 40 amps. This can be satisfied with a 50 amp receptical (80% of 50). As far as I can tell, the M3 has a max of 32 amps. I’m getting a M3 and was assuming I could install a 40 amp receptical of some kind to meet the 32 amp max (80% of 40). I have not been able to find a 40 amp NEMA receptical, however. There are plenty of 30 and 50 amp models. Is there a reason for this or am I missing something? The reason I care: I’m may be short on panel capacity and 10 amps might make the difference....
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Actually the Model S chargers are 48A or 72A now. The early Model S had 40A charger.
They only make Nema 14-30 or 14-50 receptacles. The bottom line is you install a Nema 14-50 receptacle. You can power it with a 50 or 40 or 30 or anything lower amp breaker. The 50 amp breaker will support the 32 amp MC that comes with the M3 so will the 40 amp breaker. Your choice.
My choice in your position would be a 50 amp breaker so you or anyone else with a MS 40 amp MC could charge at a higher rate. Please make sure your service and code can handle whatever breaker you install.
I'd put in the 50A. The issue with the capacity of the service is a LOAD calculation. It has nothing to do with the sizes of breakers in the box. You will not overload your service by running 32A on a 50A breaker any more than you will running it on a 40A breaker.
timk225
Active Member
Just install a 14-50 on a 50 amp breaker with 6 gauge cable and charge it. Don't over-complicate it. Putting a 30 or 40 amp breaker on a 14-50 accomplishes nothing.
Dr. J
Active Member
I'm confused, but maybe this explains it. You're getting the standard range Model 3?
"Tesla has equipped the Model 3 with a 32-amp onboard charger for the standard version and a 40-amp onboard charger for Model 3 with a long range battery pack."
A look at Tesla Model 3 charging options
I’ve read the EVSE included with the model 3 is 32a max. To get to the 40 for the LR need the HPWC (or buy the EVSE for the Model s/x)
Do the load calculation, or get an electrician to give you one. Install a 14-50 outlet, with 50A breaker if you have the capacity or 40A if that's what you can do. Either should be fine if the UMC only draws 32A. If you have to go below 40A then you should consider a suitable outlet for which Tesla has a UMC adapter. That will automatically ensure that the maximum outlet amperage (80% of breaker size) is not exceeded.
If you want to spend the money, the HPWC will also work. You can set it internally for whatever circuit breaker size you use, from 12A through 100A. Lots of flexibility there, and you can leave the UMC in the car.
If you want to spend the money, the HPWC will also work. You can set it internally for whatever circuit breaker size you use, from 12A through 100A. Lots of flexibility there, and you can leave the UMC in the car.
Dr. J
Active Member
Here are the specs: Home charging installation. I thought the limit was the "on-board charger capacity," but it's possible I don't understand electrons.
Edit: You are correct: "Model 3 includes a second generation Mobile Connector which has a maximum output of 32 amps." So they gave the LR 48-amp capacity but only provide a 32-amp cable? Will the EVSE for the Model S/X work for the Model 3?
Last edited:
Here are the specs: Home charging installation. I thought the limit was the "on-board charger capacity," but it's possible I don't understand electrons.
Edit: You are correct: "Model 3 includes a second generation Mobile Connector which has a maximum output of 32 amps." So they gave the LR 48-amp capacity but only provide a 32-amp cable? Will the EVSE for the Model S/X work for the Model 3?
It should. If the HPWC and the supercharger works.
But honestly, 30 miles per hou should be plenty for the majority of the people. Looking at that chart, my S charged at 29 with my current setup. I typically throttle it back to 30a.
How many miles a day do you need?
Dr. J
Active Member
To be clear here the LR Model 3 has a 48 amp onboard charger.
The included UMC is limited to 32 amps. On a Nema 14-50 with either a 40 amp or 50 amp breaker the UMC will charge at up to 32 amps.
The HPWC installed with a 60 amp breaker will charge at up to 48 amps.
For reference the Tesla charging page has been updated to include Model 3 information:
Home charging installation (On the US charging page only. Old info on CDN page)
The included UMC is limited to 32 amps. On a Nema 14-50 with either a 40 amp or 50 amp breaker the UMC will charge at up to 32 amps.
The HPWC installed with a 60 amp breaker will charge at up to 48 amps.
For reference the Tesla charging page has been updated to include Model 3 information:
Home charging installation (On the US charging page only. Old info on CDN page)
Last edited:
Model 3 SR will be 32A.
Model 3 LR will be 48A.
IANAE. According to other people on the Internet, it's the breaker that's determines the receptacle. You can't get 14-40 so you use 14-50. Don't know what that would imply for wiring requirements but I assume that your electrician should wire it as if it were a 50A circuit.
Last edited:
mspohr
Well-Known Member
I charge my older Model S (40 amp max charger) with a HPWC and set it to 32 amps. This is for maximum efficiency. Never have a problem with getting a full charge overnight.
Just install a 14-50 socket with a 50 amp breaker (6 gauge wire is better than 8 gauge). The car will pull 32 amps and everything will run efficiently.
Just install a 14-50 socket with a 50 amp breaker (6 gauge wire is better than 8 gauge). The car will pull 32 amps and everything will run efficiently.
davewill
Active Member
You can do 40a or you can do 50a. The 50a receptacle with a 40a breaker is a VERY common install in the non-Tesla world of mostly 30a EVSEs. I have such an install myself (40a circuit to a 6-50 receptacle) as I started with a LEAF, and even though my current car can do 40a charging, there is no real need for me to upgrade the circuit. If the cost difference is minimal, then do the 50a, if 40a is easier, then there's no real problem with it.
Edit: One caveat that occurred to me. If you do the 40a circuit, you may find it annoying that you can't easily plug a standard UMC in because it assumes a 50a circuit is available if you have a 50a plug.
Edit: One caveat that occurred to me. If you do the 40a circuit, you may find it annoying that you can't easily plug a standard UMC in because it assumes a 50a circuit is available if you have a 50a plug.
This is a good point. If you use a 50a plug and a UMC you will have to manually set the current in the car. People have noted it can occasionally get reset with firmware updates or the GPS can be off and the current not limited as expected.
I'd spend the extra $$ for the true 14-50.
Back to the original question... I think the reasons why the included portable charge cable is 32A only is:
#1: Cost savings on the included one... Buy something more capable (and expensive) if you really need it.
#2: Safety reasons. Some heavily used NEMA14-50 (like at campgrounds) are somewhat worn out, and don't make great contact. Safer to charge at lower amps to prevent overheating. I think maybe Canadian electric code is suggesting 32A for this purpose as well.
#1: Cost savings on the included one... Buy something more capable (and expensive) if you really need it.
#2: Safety reasons. Some heavily used NEMA14-50 (like at campgrounds) are somewhat worn out, and don't make great contact. Safer to charge at lower amps to prevent overheating. I think maybe Canadian electric code is suggesting 32A for this purpose as well.
Last edited:
Similar threads
- Question
