Using the Primes 120v Charger at 240 Volts, Cost $20 !!!

I came up with the following parts - does this seem correct?

50-Amp 125/250-Volt NEMA 6-50p Heavy-Duty Straight Plug

20-Amp 125-Volt NEMA 5-20r Heavy-Duty Straight

10-3 Black Soow Power Cord Power Cord (By-the-Foot)

 

That's pretty much it, but for the nema 6-50p plug I would get a right angle instead of straight. Less strain and would fit better on outlets with outdoor cover on it.

 

Great call. Unfortunately, the electrician already installed the straight plug.

 

That'll work. Since it already has a straight 6-50P on it, you can always rig up a hook to hang the "brick". That's a good thing to do anyway to relieve the strain on the cord connections.

 

IMHO this is wrong from a safety perspective.
You now created a 120V looking outlet delivering 240.
Now you and I know this today, but it may cause trouble.

I strongly advise to go the other way.

Cut the 5/20 of the OEM EVSE and replace it with an NEMA 6-20p.
It can now only plug into 240 - without adapter.
Use a NEMA 6-20r on your extension cable/outlet.
It delivers 240 and shows it.

Create yourself a 12" adapter cord with NEMA 6-20r (female) on one side and NEMA 5-15p (male) on the other side if you ever want to take it on the road and be able to plug into a household outlet.

Safe all around... as long as we assume the EVSE will actually properly function at 240 as we all do by now. Worst case it blows the EVSE - new one are $150 - $200.
This will NOT damage the car charger as an EVSE is just a passive pass-through for the power.
The control lines tell the car there is a charger and how many amps it is allowed to take.
The car will never take more than it can handle.

hope this helps,
Hein.

 

You can not cut the plug end of the OEM EVSE. There is a temperature probe in the plug.

 

Welcome, Hein.

What about the temperature sensor in the plug you'd have him cut off of his EVSE?

The 50A NEMA 6-50p is a 240V outlet, not a 120V outlet delivering 240. So the outlet is safe. What he had originally was a 120V outlet that delivered 240V and he wisely got it changed after our warnings that someone could get killed.

The adapter is safe as long as he keeps it secured to the EVSE so that it can't be left hanging in the outlet alone. There are no guarantees that the adapter won't be misused, but there are also no guarantees that the car won't be misused either.

 

Interesting! Good to know it was anything more than a dumb plug.
I scanned many of the dozens of replies in this chain, but did not notice that tidbit of information.

Best solution might be to simply sell the OEM charger and buy a better one for potentially less money.
I just sold mine on Ebay for $220 and paid $13.75 for it shipping. Some ask $300+
I bought a generic one with selectable amps and 6/20 - 5/15 adapter for $159.

hope this helps,
Hein

 

I’ve read all previous posts and am going to build my adapter to use my 240v 10-30r drier outlet in the garage but I have two questions:
1. Can I leave the adapter, while connected to the brick, permanently plugged into the 240v outlet and not overheat the brick? I’m doing this now with the stock 120v plug with no problems.
2. My 240v outlet is also wired to my drier in the house, on a 60 amp circuit(2 30’s). The drier is 25 amps. Am I correct that using the Prime charger and cord which draws 12 amps at the same time as drying some clothes at 25 amps would pose no problem?
Thanks for the help and all the reassurance from this thread.
Bob

 

If the breaker is a ganged pair of 30 amp breakers, then it is a 30 amp circuit, not 60 amps. One 30 amp breaker is on each of the two hot lines, no breaker on the neutral wire (if present at all).

Then, NO!, you can't run the drier and Prime charging at the same time.

Can you see what wire gauge is used? 10 gauge generally means a 30 amp (or less) rating.

 

Fuzzy1, thanks for the reply. I guess I need to rethink maybe putting in a separate 40 amp circuit to be safe and cover a possible future bev.

Would it be okay to leave the brick plugged into the 240v 10-30r, with the adapter of course, without overheating the brick? I’m thinking there’s no current running through there unless it’s charging for a couple hours.

 

Fuzzy1's comment about the 2 30-amp breakers is spot on. Normally, one would expect this circuit to be protected by a single double breaker so that both sides would shut down at the same time if overloaded or switched off. The problem with the two separate breakers is that you can shut down one side of the 240-volt circuit and still have the other side live. Each side provides 120-volts when measured against the neutral (and ground) wires, so if you shut down only one side, you can still have 120v power present at one side of the outlet. Be careful.



As for supplying 240-volts to the OEM "brick" -- I believe it has been concluded that the "brick" is designed to work at 120v or 240v safely because it is the same device that is provided (with a different plug) with Prius Primes which sold in those parts of the world where 240v is the basic standard voltage. I doubt that your leaving it plugged in to a 240v circuit will do any more harm or make it run any warmer than if it were left plugged into a 120v circuit. (That being said, whenever you leave anything plugged it you expose it to voltage spikes, lightning, people tripping over the cord, etc.)

 

Solid stuff, Old Bear!

 

Thanks for the info. I do think the center graphic should also be yellow at the end and say 120v however.

 

While it may just complicate and confuse, it the middle graphic, when the red side of the circuit is switched off, the two "unlighted" bulbs become in series across the 120v between the neutral and black -- and therefore (assuming they're the same wattage incandescent bulbs) they would be glowing dimly at 60 volts each.



Great question for a test on basic electricity.

 

I've seen strange and ultimately very expensive damages resulting from having one side of the 220v feed go out leaving the other side and neutral live. I wouldn't want to test the effects of doing that on the charger.

 

I probably won’t run into that fortunately, as my circuit is a ganged pair of 30’s. And if I put in a 40 or 50 amp circuit those will be ganged too, and very expensive too at $190-$250 for 75’ of 6 or 8 gauge wire! I may just use the 30 amp dryer circuit that’s near the garage, use it sparingly, and put a very large “caution” sign by the safety-covered 10-30r to not use while the dryer is running ! Thanks to Rob and all the rest for your input on this!

 

They'd have to the same wattage at the same voltage. If the center bulb is rated for 240V, and the side bulbs rated for 120V, then their resistances are not that same, and this voltage division is busted.

And a 240V bulb run at 60V is going to be very dim.

 

If someone could help! From what I can gather this adapter plug would work? Southwire-1-5-ft-14-3-STW-30-Amp-to-15-Amp-Amp-RV-Power-Adapter-Extension-Cord-with-Power-Light-Plug

 

Not if you want 240V charging. That adapter is made to allow you to plug a 15A 120V cord into a 30A 120V outlet. It will allow you to plug your Prime's EVSE into one of those 120V camper outlets but you'll be charging at L1 same as if you plugged into your regular wall outlet.