You can also jumper the neutral to the ground. They are generally on the same ground bar that all the grounds and neutrals are wired to in the circuit breaker box (you should go look to prove it to yourself). So: Your 4 prong would be L1, L2, Ground, and (ground)neutral, alla same alla same.
I am now waiting for some 50 year electrician to tell me that all these years I have been wrong and my car won't charge. I don't use an EVSE other than the outlet plug, so I can't tell if the neutral is used or not.
BZZZzzzzt!
Where's FlasherZ when you need him? :smile:
No one said the car won't charge with your proposed adapter wiring. But your connection of ground to the neutral pin is completely unnecessary and exposes a potential fire danger.
There's a good chance that 6-50 outlet was wired with 6/2 romex, with no neutral wire (6 ga romex is expensive, and 6/2 is ~33% cheaper than 6/3). A quick look at Southwire's web site (if you buy romex at a big box store, it was probably made by Southwire) shows the ground conductor in their 6/2 romex is 10 gauge:
http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheet6
So now you've built an adapter that co-opts the ground wire into service as an undersized neutral, and allows plugging in a 50A/120V load into an outlet. The undersized "neutral" will be carrying way more current than is safe, and could easily overheat and start a fire.
Where do you find a 120V/50A load? Beats me, but I bet Mr. Murphy can find one.
tl;dr - Jumpering neutral to ground is unnecessary, the car doesn't need it, and is a fire risk. Don't do it.
-1 (biting my tongue here so I won't be admonished by the mods (again))
I guess you have more sense than me... :wink:
Usually if something wants to use the Neutral too it is because it needs 120V as well as the 240V. In that case, without a Neutral, it just won't power up.
Possibly. If all of the 120V loads are wired from the same hot to the non-existent neutral, then yes, it won't power up. But if the 120V loads are split between the two hots (like a big RV with a 14-50 shore power plug), things get ugly quickly, generally resulting in something going boom from voltage spikes (ie, turn on the microwave and the TV on the other hot leg fries).
- - - Updated - - -
This was my concern... that something in the box needed the 120 from one phase. I didn't think it was likely because they probably sell exactly the same box to elsewhere in the world where they don't have 120 at all.
Thanks again!
The UMC doesn't need the neutral. I've charged a car with a 6/3 extension cord that does not pass the neutral (H1/H2/ground only)
People have cut off the neutral pin of a 14-xx adapter to allow it to be plugged into any 14-xx series outlet. Obviously, this is only 100% safe if you are plugging into a higher amperage outlet (ie, a 14-30 adapter in a 14-50 outlet), and somewhat less safe if you intend to remember to dial down the current when plugging into a lower rated outlet.
See Cosmacelf's guide, page 16:
http://cosmacelf.net/Home Made Adapters.pdf where he shows cutting off the neutral pin on a 14-50 UMC adapter to plug into a 14-60 outlet.
You should really read that guide, if you haven't already, before making any adapters. Lots of good info and safety warnings.
