Can I Wire a 240v Dryer to a Plug (UL Listed NeoCharge Splitter)

Question

I just purchased an EV car. Unfortunately, my electrical box is a long way away from my garage and the box wouldn't support 50 more amps. I'm looking to use my dryer power supply, using the NeoCharger (https://www.getneocharge.com/smart-splitter).

My issue is that my garage has an upper area where the laundry is. A junction box to the dryer outlet, with 30 amp 240 service, is within five feet of my EV car on the lower level. I want to connect the NeoCharger there but am running into issues with how to wire it.

Can I take the feed from the 240v outlet and add a plug to it and plug it into the NeoCharger (wired to an outlet I would install in place of the junction box)? In essence, the 240v dryer outlet would now get power from being plugged into the NeoCharger. I would then plug the EV charger into the other side of the NeoCharger. Is there another way to make this work? 30 amps (24 usable) is fine for my needs for EV charging.

In the alternative, I could just put the NeoCharger where the laundry area is, buying a long extension cord to go to the lower part of my garage, but that would require the extension cord passing through the floor or wall to the lower level. Any way to make this alternative work?

Thanks for any help!

Answer 1

This unit. Hmmm.

The UL Listing on this unit looks legit, I'm looking at a photo of a unit "in the wild" with a proper File Number and yet a 3-prong socket. My research thoroughly checks out, they even applied for a California research grant. This is a small "mom & pop" US company that builds in California for Pete's sake - fully within reach of US regulatory talons. The UL listing can only be legit. Clearly, they found a way to make the NEMA 10 style connection less dangerous (?) in a way that fully satisfies UL.

So a first - no McKayla Maroney face from me, my tail is wagging. However their product doesn't make any sense for two EVs - Share2 does that, and does it better.

However, when UL approves an item, they approve paper instructions. These are important as they define the scope of testing, and they MUST be followed per NEC 110.3, and override any "more fun" multi-media instructions. Hiding them is a red flag. I'd like to see them.

It may not be necessary at all.

There is no limit to the number of receptacles on a 30A circuit. This has come up in the past here, and we have not been able to find any rule against this. So I do not see a problem with simply extending a legal, grounded 30A circuit to the garage and having a second receptacle there. Don't use the dryer and EV at once.

Note that an ungrounded circuit cannot be extended, unless you retrofit ground to the original location. (the GFCI solution below does not allow extension).

Those pesky ungrounded circuits and NEMA 10 receptacles.

NEMA 10 is a World War II era connector that does not provide safety ground. The madness of using this should be obvious. Even worse, on dryers, Code says to bootleg chassis ground to the neutral, on the logic that NEMA 10 sockets are rarely disturbed -- however, if they are disturbed and the neutral wire loses contact, this guarantees the chassis of the machine will be energized with 120V. Guarantees. The media reports these fatalities as a "miswired" socket, it was correctly wired and simply wore out. That shouldn't be possible, hence the ban.

Code never forces retrofit of things which were legal at the time of installation; this is called "grandfathering". However, such circuits cannot be modified or extended.

There are generally 3 solutions to a NEMA 10 outlet:

• Open it up and discover there are separate neutral and ground wires in the box after all, or metal conduit rated to provide ground. Code required all dryer sockets to be wired this way as soon as the supply of ungrounded 3-wire was exhausted.

• "Retrofit Ground" to that location using the now-liberal retrofit rules. A #10 ground can be run back to the panel obviously, or to the Grounding Electrode System (that bare wire going off to ground rods), or to any junction box with #10 or larger ground going back to the panel. (Grounds can be shared among circuits, since they only carry current during a fault).

• Leave the circuit groundless, GFCI-protect the circuit at the breaker, fit a NEMA 14-30 receptacle with ground unconnected, and mark it "GFCI Protected / No Equipment Ground".

That is why I'm so keen on seeing the UL-approved instructions. Perhaps they approve 3-prong pass-thru to a dryer. If they do, that is that. (why would they approve that? Does the unit have GFCI?)

Proper in-wall wiring, though.

Routing an extension cord through a wall is not legal and cannot be done. Any thru-wall wiring must be done with proper in-wall wiring methods, e.g. NM cable and junction boxes in jurisdictions which allow NM cable (not Chicagoland).

If you are simply extending the circuit, this is straightforward standard wiring.

It is perfectly legal to use in-wall wiring methods in walls to connect an inlet to an outlet, that is otherwise isolated. For instance you could have a 10/3 NM cable in the walls between two junction boxes, with a NEMA 6-30 or 14-30 socket on one end, and a NEMA 6-30, L6-30, 14-30 or L14-30 inlet on the other end. Jay613 wisely pointed out in another discussion that the "L" twist-lock inlets may be more readily available than the non-"L". Then have an adapter cord that takes an L-x-30R (inline socket) to a "normal" 6-30P or 14-30P.

Answer 2

Adding this answer just to show what a Frankenstein's monster you'll need to build to do this "properly" with the device you've proposed given your existing wiring, location of devices, and the way this Neo gadget works.

This is all premised on having a 4-wire supply from the panel, (live/live/neutral/ground) as you confirmed in a comment.

A bunch of new boxes "downstairs" to house an outlet and two inlets. The cable to the dryer is in the existing box, but now connects to a new inlet via new wires through Conduits A and B. Conduit C serves only to supply grounding to the charger without relying on the Neo device for ground. IE if you unplug the Neo or if it fails, the conduit and boxes to the charger are still grounded.

This is outrageously expensive and ugly for what it provides. Surely there is a device that works like the one you found but is designed for installation inside a junction box? Look!

You'll have to find two short power cords with NEMA 14-30 plugs and L14-30 sockets, or you'll have to find non-locking inlets.

Answer 3

I just noticed that the device you want to use to switch power between your charger and dryer costs $500. A system of outlets and inlets that would allow it to be used would cost you another $100. All this is in aid of time-sharing your last remaining 24 amps between the two devices and postponing the installation of a proper feed wire to your garage.

Here's my advice: Don't waste so much money!

You said your charger is within five feet of a junction box carrying the wires on the way to your dryer.

Just install a manual DPDT switch such as the Leviton 1288 or Hubbell 1388 (for example) next to the charger and get into the habit of using it. Your car will have power at night, your dryer in the day. If you need to dry clothes at night you'll need to go downstairs and flip the switch.

The switch can go in a normal junction box, probably in the existing one with an ordinary face plate and you won't need any NEMA 14-30 or 10-30 plugs or sockets or cables.

I know it's not what you asked but now I've seen the price I have to make this suggestion as a better way to temporarily plug the hole, and saving the $600 or so to put towards a better permanent solution.

You still need to consider the issues in Harper's answer, determine whether there is a proper ground wire available in the junction box and act accordingly.