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Connecting HPWC to 14-50 outlet

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Has anyone plugged their HPWC into an 14-50 outlet, rather than running new power connection?
Yes. I used a 50 amp appliance cord from Home Depot with a 14-50 plug. I trimmed the cable to approximately 15" and prepped the ends of the L1, L2 and ground wires with crimped on ferrules (the white neutral line is not used so I capped that with a wire nut). Installed the wires and set the internal dial to 40 amp.
Works great.
 
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Reactions: JPUConn and Rocky_H
You can also remove the outlet, reuse the outlet box as a junction box, replace the cover with one with a hole for flex conduit, and hard wire it in. I personally think putting a plug on the HPWC is a better solution, but some people think it doesn't meet code.
 
Ok, so I just did this modification. Now before I get into it, I suspect this isn't up to code. Many people have made that clear. If this will upset you, please stop reading now. ;)

I got a used HPWC with the P85D I just bought. I didn't want to hard-wire it in, since I might be moving it to another location soon. At this location, I have a 30amp 14-30 outlet. I've been using a NEMA 14-30 to 14-50 adapter I built according to this site: http://cosmacelf.net/Home Made Adapters.pdf which I've been using for years with my UMC and 14-50 adapter.

So since my other location already has a 14-50 outlet, I decided to add a 14-50p to power the HPWC, and also use my 14-50->14-30 adapter I already have to charge at 24 amps here, and 40 amps at the other location.

That said, I bought this from Amazon: Amazon.com: TES 4 Ft. 6/2-8/2 50 Amp 4 Wire Range Cord Kit: Appliances for $20.

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I clipped off the crimped tabs.
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It's a pretty straightforward what goes where according to the install PDF from Tesla:

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But I didn't like how the ground wire was being pulled out of the ground bus.

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So I pulled everything back out and started over. I removed the ground bus by removing the green screw, and reset the ground wire to the outside open ground connector. Much better.

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Ground wire fix:

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Here's a pic of the final install:

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Turns out the previous owner when unscrewing the cover panel stripped out the threaded brass threads for the two torx security screws... so I had to epoxy them back in.

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But when I got it all back out to the garage, it didn't work.. no power, nothing. Tried the reset button, still nothing. No status lights either. So I dragged it all back upstairs to my workbench, and tested all the connection continuity, and it's all good. The UMC still works on the 14-30 adapter.

So I started to look at the "Reset" button, which you're supposed to press for 5 seconds to reset the HPWC. As is common, the reset button is a small PCB mounted momentary button, and the reset button on the case is just plastic that bends inward to hit the PCB button. Well, it wasn't reaching far enough to actually hit the button. It was close, but not enough for it to make solid contact. So I cut up a small strip of a credit card, and stuck it between the case and the switch, now the outside button make actual contact with the PCB switch.

Put it all back together, and lug it all back down to my garage. Plug it in, still nothing. No lights, no contactors, tried the reset button for five seconds and still nothing. But then I tried pressing the charge port door release button on the handle.. and voila! The charge port door opened. So I figured the handle must be getting power, let me try plugging it in. And the car starts to charge normally, up to 24 amps. (The DIP switches are set for 24 amps at this location).

Turns out the front panel display is toast. Not sure how that happened, or if the PO damaged it when un-installing the HPWC, but it seems to be working just fine, but just no front panel display or feedback.

Here's the final set up working (yes, it's not wall mounted either, not yet, anyway):
IMG_5666 (Small).JPG


Use at your own risk. YMMV.
 
Nice job documenting it. You could also cut off the neutral blade and freely plug it into either outlet without needing the adapter...of course I keep telling myself I'm going to do that, and never get around to it...
I did that (cut off the neutral blade) on an OpenEVSE I built. Just make sure you start with a heavier gauge range cord, not a dryer cord - you don't want to charge at 40A through a wimpier dryer cord that can't safely handle more then 24A.
 
I queried Tesla's charging team on this.

If we are planning to charge when a 14-50 outlet is present, they recommend ordering the "Corded Mobile Connector - NEMA 14-50" (for $520, with a 20 foot cable) than an HPWC and adding a 14-50 plug (for $500 with an 8.5 foot cable and $550 with a 20 foot cable).

My wife asked about this last night, as we are getting ready to receive our 2nd Model S in the next month. Instead of ordering a second HPWC, and then either paying to get it installed or adding a 14-50 plug to it, I'll probably order the 14-50 CMC and the $25 Cable Organizer. That will provide the same charging as an HPWC on a 50A circuit, stays within code, and still gives us the flexibility of plugging in a UMC, should the CMC fail. Plus, should our HPWC fail, we can use the 20 foot CMC cable to reach both Tesla cars in the garage.

It is surprising though that an HPWC costs $500 and the CMC with the fixed 14-50 plug costs $520...