Please reference this chart (below) as it will help explain my comments.
Here's what I've learned about these adapters and wiring in general. Sorry if my comments are a little disjointed, hopefully they make sense. If not, ask...
- The Nissan L1 EVSE (modified or not) will not function without a ground and will show a trouble light. Thus, you can be comfortable in knowing that it is grounded if it's working at all.
- 120v circuits use 3 wires (hot, neutral and ground).
- 240v circuits use 3 wires (hot, hot and ground).
- Some circuits use 4 wires (hot, hot, neutral and ground) to offer both 120v and 240v in one plug. When using the modified EVSE with this kind of an outlet, the adapter will simply not connect the neutral line to the L6-20 plug side.
- The modified EVSE uses a standard 240v L6-20 plug as it's "native plug".
- Because electricity flows between hot and neutral on 120v and between hot and hot on 240v, Phil's optional 120v adapter works by connecting one of the L6-20 hots to the 120v neutral. Because the modified EVSE now has an auto-sensing transformer, this arrangement works just fine. Since 120v and 240v aren't normally compatible, you are unlikely to find this adapter anywhere else, so please do purchase it from Phil as part of your upgrade. Also, do NOT try to use it with anything BUT this upgrade or you're asking for trouble.
- The red X's in the diagram indicate where similar plugs differ from each other.
- NEMA 5-15 is the common 120v 15a household plug.
- NEMA 5-15 and 5-20 are very similar. An unmodified 5-15 plug will also fit a 5-20 outlet.
- NEMA 6-50 is a common RV plug and is also used for industrial welders and similar equipment.
- It is common to find 6-50 plugs that allow you to unscrew them and rotate the pin orientation. With this kind of a plug (such as this leviton one), and a screwdriver, you can make an adapter that will fit both 6-30 and 6-50 outlets.
- If you buy a NEMA 6-30 or 6-50 adapter pre-made, it may not use an adjustable plug type - so double check that or make this one yourself with parts from your local hardware store. Just be sure to use a properly rated wire.
- NEMA 10-30 and 10-50 are the older style appliance plugs commonly used by older dryers and ranges. Most appliances use both 120v and 240v internally, but this plug does not have separate neutral and ground pins - so the appliances would use the ground as a neutral (which is why the diagrams above label that pin as W). This practice is no longer considered "safe" and modern appliances now use the NEMA 14-30/14-50 outlets instead.
- However, since the wall outlet side of a 10-30 or 10-50 is typically connected to ground, it is perfectly safe to use the modified EVSE with this outlet since it doesn't need neutral in 240v mode anyway. In the event that you do actually find an outlet that is wired to neutral, the EVSE will not function and will show an error light, so you're safe either way.
- NEMA 10-30 and 10-50 plugs differ only in the shape of the "neutral/ground" pin. With careful modification using a dremel (or similar tool), one adapter can be made to fit either outlet. Simply remove the X'd out portion.
- Because 10-30 and 10-50 plugs often use the ground as a neutral (as per above), you are unlikely to find pre-made adapters as most places aren't willing to connect the W pin on it with the G pin on the L6-20. You'll likely have to special order this, or make it yourself. Like the 120v adapter, for safety's sake do NOT use this adapter with anything other than the modified EVSE.
- NEMA 14-30 and 14-50 are the modern appliance plugs designed to replace the old 10-30 and 10-50 plugs with a safer design that has separate neutral and ground lines. These are also commonly used at campgrounds and some industrial settings.
- NEMA 14-30, 14-50 and 14-60 plugs differ only in the shape of the neutral pin. Since the modified EVSE doesn't use neutral at all in 240v mode, carefully remove the (X'd out) neutral pin with a dremel (or similar tool) and one adapter will fit all three plug types. To avoid accidental contact between the removed pin and the outlet, cover it with electrical tape.
- Most residential and industrial 240v outlets are NOT GFCI plugs. If you use an extension cord with this kind of non-GFCI plug, for safety's sake keep the extension cord and the EVSE "brick" indoors. The J plug can safely be used outdoors because the EVSE itself has GFCI protection built in - but that only protects between it and the J plug, not between it and the wall!
- http://www.stayonline.com/nema-20-amp-l ... -208v.aspx
EDIT: Fixed a typo and added emphasis as per LEAFer's suggestions. Also revised the wording about "properly grounded" as per Wayne.
EDIT 2: Added link to thread where you can buy the adapters.