Tesla 240-volt adapters…
This Could Be Dangerous. Worthy of an Article?
Hey Mike,
Perusing Amazon I came across this adapter. It is advertised as for RV's. It takes a 3 wire 220 vac outlet and converts it to a 4 wire outlet. Except......it connects the four wire side neutral to the 3 wire side ground, and does nothing with the ground. So now, your neutral and all of its important functions, are dependent on ground. And, the ground to the RV is open. I found it on Amazon HERE. - Allen S.
Product details
Brand
Siawclub
Color
yellow
Connector Type
Plug in
Specification Met
NEMA
Amperage
30 Amps
UPC
757807137858
【Easy to Carry Nema 14-50 Adapter Compact in structure, eliminating heavy extension cords, weighing 0.6 pounds, compact and lightweight, easy to carry when going out.
【NEMA 10-50P to 14-50R Adapter】The Welding plug converter is NEMA 10-50P to 14-50R, used to connect a 3-pin 10-50 male plug to a 4-pin 14-50 female socket, and can be used for electric vehicle charging.
【NEMA 14-50R】NEMA 14-50R, 50A, 125/250V, 4-prong female connector, compatible with generators and regular RV parking lot 50A power sockets.
【NEMA 10-50P】NEMA 10-50P, 50 amps, 125/250 volts, 3-pin male for 10-50R 3-pin sockets.
【SMALL and CONVENIENT】1ft/35cm power extension cord, very convenient to carry at any time, plug and play, fast to use.
Hey Allen,
All I can say is WOW! While this type of 6-50 to 14-50 adapter will work for a Level-2 Tesla EV charger, it’s not suitable for an RV.
But I think that contrary to your assertions about the ground being open on the 14-50 RV side, I’m guessing they’ve tied the ground and neutral together. That’s nearly as bad as your guess since it could work at low current levels by using the ground conductor as the neutral, and that’s a big no-no since the ground conductor isn’t supposed to carry any load currents. Read my previous article on Welder Outlet dangers HERE.
How a welder outlet is wired
Note that a 6-50R welder outlet has two hot legs and a ground, but no neutral. Welders and EV chargers are okay with the lack of the neutral, but an RV really needs that conductor path to the service panel
How an RV outlet is wired
If, as I assume, the 50-amp RV side of the adapter has a jumper between the ground and neutral contacts, this would measure okay without a load. But any significant load amperage could cause the neutral/ground connection to fail, and that’s would allow the incoming split-phase 120/240-volt service to divide unevenly. It can turn into 140/100 volts, 160/80 volts, or even 200/40 volts. And that much over-voltage can easily destroy much of your RV’s electrical system.
I’ve just ordered one to confirm its wiring
Yup, I’ve just ordered one from Amazon so I can confirm how the 50-amp RV side of the adapter is wired. Basically, since so much of what’s posted on Amazon is wrong or confusing I don’t trust any of it. I’ll do a full review of how this dangerous adapter is wired next week.
Let’s play safe out there… Mike
Thanks for your diligence. Please consider adding that all 3 wire range/dryer outlets are the same as the welder outlet, lacking the neutral. Please include the evaluation of the code concerning the eary days when ranges and dryers didn't have lights and clocks, not needing the neutral, and the 4 wire requirements addressed this problem. Lastly, maybe add a small statement about the use of a AC disconnect as a quick way to power a RV in a jam. Same neutral/ground situation.
Do you notify Amazon and/or the seller if you find devices that are dangerous? curious if Amazon pulls them off their site.