freeewilly
Member
How can I tell if I have 220v or 240v installed?
I have an old dryer's plug (NEMA 10-30) with 30 amp breaker.
I have an old dryer's plug (NEMA 10-30) with 30 amp breaker.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
That is definitely a 220V outlet. Grab a 10-30 adapter from Tesla and plug it in! It will automatically dial down to 24A and give you ~18 miles/hour charge.
That is definitely not a 220V outlet(it's a 240V outlet, split-phase 120V. With losses you might be seeing closer to 235V, but 220V seems kinda low)
Oh, I thought they were asking if a 10-30 dryer outlet was 220 or 120V. ~220VAC is common out in the country, far away from distribution relays, run through older infrastructure. I have that situation at a property.
freeewilly
Member
That is definitely not a 220V outlet
Thank you both Chris TX and Max* for the answer. I replaced the 10-30 with a 14-50 plug, but still use the 30amp breaker. I dial down to charge at 26 amp.
Did you run a new ground wire? If not, that's not a legal/code compliant installation. And you need to dial down to 24A, not 26A. Even then, there's issues (common example given is a software update resets your charge rate to 40A, and you have a fire risk).
freeewilly
Member
I don't charge at home often, maybe once a week. I'm aware of the risk, my breaker tripped once due to the car reset back to 40A. Since then I'm very careful and check the charge amperage every time I charge at home, as long as the MS don't reset back to 40A during the charge, I should be okay. I will dial it down to 24A from now on.
- - - Updated - - -
The ground wire is already there, it didn't connect with old dryer's plug, I connect the ground wire when I install the 14-50 plug.
- - - Updated - - -
The ground wire is already there, it didn't connect with old dryer's plug, I connect the ground wire when I install the 14-50 plug.
Sounds like the old plug was mis-wired. It should have had a ground wire and two hots connected to it. The 14-50 adds a neutral wire in addition.
You really should put the 10-30 back and find a Tesla 10-30 adapter.
Thanks for all the great info. I am 14 miles from work, so either I mistyped or someone misread in saying 50. It is 30 round trip. I figured a 90% charge before I left on Friday. The car is garaged and only goes below 50 degrees when it is lower than 10 outside. I also go to whole foods on Sunday mornings when they open, and the supercharger is only a mile or two from there. At 8 am on a Sunday, I cannot imagine having a line to charge, if I need it. If this becomes a pain, I will have the line run. I also have a Prius as an extra car for about a year, until my daughter gets her license. Someone also gave me their old 30amp 1772 charger from their volt I could install in the garage.
I have to tell you, I will be disappointed if real world range (standard charge and occasional spirited driving with a 20 mile buffer) is less than 175 miles except in extreme conditions.
i have a delivery appointment Monday at 3!
I have to tell you, I will be disappointed if real world range (standard charge and occasional spirited driving with a 20 mile buffer) is less than 175 miles except in extreme conditions.
i have a delivery appointment Monday at 3!
nwdiver
Well-Known Member
Doesn't really matter so long as you have two hot legs... The UMC will work with 200v - 250v. I plug in at hotels a lot and they're usually only ~208v.
It sounds like he had a 4-wire installation, with 2 hots and a neutral to the 10-30, and an unconnected, separate ground. If so, that's sort of OK, but it should really be a 14-30. It's OK to install a 14-50 on a 40A circuit if a 40A appliance (like some ranges) is connected, but a 30A circuit is probably a no-no (especially since the UMC with a 14-50 isn't a 30A amp appliance). I'd try to scrounge up a 10-30 or 14-30 adapter, and use the matching outlet.
The 10-30 is a hot-hot-neutral receptacle. If he had a ground in the box, then it is a good install if you replace it with a 14-30. A 14-50 is not legal to install if the load you connect to it expects a 50A circuit.
- - - Updated - - -
It all has to do with nameplate load. It is not legal to attach a UMC with a 14-50 adapter to anything but a 50A circuit. Nothing wrong with a 14-50 receptacle on a 30A circuit, as long as you only attach appliances with nameplates of 30A circuit rating max. There is a code provision that requires 40A or 50A circuits for a 14-50 when there are multiple receptacles on a single circuit, but the EV portion of the code requires that any receptacle used for EV charging to be a single receptacle on a branch circuit.
Similar threads
