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I have an EV that, like most, came with a Level 1 EVSE that can charge my car with 12A @ 120V. Now, I'd really like to be able to charge at work without needing to buy another EVSE, but at work, we only have NEMA 14-50 receptacles, which provide up to 50A @ 240V. I am aware that I can just take one of the hots, the neutral, and the ground and get 50A @ 120V, but I'm curious if my EVSE can handle a 240V input.

Basically, I'm hoping to get rid of the neutral from the NEMA 14-50, wire it to a NEMA 5-15 receptacle, but with the neutral as the second leg (as if it were a NEMA 6-XX instead).

Can a 120V EVSE handle 240V, and has anyone done this?

  • I just did this very thing with the EVSE’s on my Chevy Volt and Smart Fortwo electric drive. No internal modification needed. Just made an adapter that uses the neutral (white wire) for another 120 volt wire. What kind of car and EVSE do you have? – user35357 Feb 5 '18 at 19:09
  • I already made one, but thanks for the comment. It's not quite what I was asking about, but it's what I ended up doing. – Hari Ganti Feb 6 '18 at 18:57
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NO, 120v is not the same as 240v (are there several phases in this NEMA 14-50 sockets - is 120v available directly?). One possible solution is to use a "drop-down" transformer 240 to 120v, but one that is capable of 1500W will be large, heavy and expensive. They are fairly common in the UK to provide 120v on building sites for power tools...

  • I am aware of the difference between 120V and 240V... However, when you look at the standard for a J1772 connector, one ungrounded conductor is marked as L1 (Leg 1 @ 120V to Neutral), one is marked as L2/N (Leg 2 @ 120V to Neutral OR Neutral), meaning the cable is identical for both use cases. Additionally, most EVSEs are pass-through devices, meaning they don't regulate power flow, only monitor it to ensure safe delivery. I've heard of this transformation being done before (on Nissan Leafs), but I wanted to get direct feedback from someone who's done it, or knows why it can't be done. – Hari Ganti Feb 24 '17 at 19:14
  • Either way, I plan to adapt the NEMA 14-50P to a 5-15R with a 15A resettable fuse. I'll just be throwing away one of the 120V legs from the 14-50. – Hari Ganti Feb 24 '17 at 19:15

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