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mknox
Well-Known Member
What I did is go out and buy a stove cable set from Home Depot similar to this and simply wired it into the HPWC and set the DIP switches for 40 amps delivered. I then just mounted the HPWC near the outlet and plugged it in.
If you're looking to get the full 80 amps from the HPWC (or anything higher than 40 amps) you'll need to re-wire as the circuit to your 14-50 will not likely be adequate.
If you're looking to get the full 80 amps from the HPWC (or anything higher than 40 amps) you'll need to re-wire as the circuit to your 14-50 will not likely be adequate.
mknox
Well-Known Member
There was nothing in my HPWC installation manual specifically prohibiting this, which is where code requirements would come in, but checking local codes would certainly be the prudent thing to do.
I just went ahead and did it. I figure it's no different than an electric range, which is (or should be) fastened to the wall to prevent tipping, and is also plugged into a NEMA 14-50 outlet
Canuck
Well-Known Member
I did the same thing as @mknox for my home setup. When the price of the HPWC's fell from $1200 to $650 a lot of people started to do that. There's threads here about it, such as:
HPWC connected with a plug to a NEMA 14-50
HPWC connected with a plug to a NEMA 14-50
I guess I virtually upgraded, since I was installing a 14-50, then upgraded to the Wall Connector before actually installing the plug. I realized that the particular wire to my plug was sufficient to run the Wall Connector at 48 amps, rather than the 40 amps of the Mobile Connector. I was going to buy an extra, dedicated MC, but then realized I could get the extra bit of power from the Wall Connector for just a few dollars more, I switched and got the Wall Connector.
davewill
Active Member
It's also pretty easy to remove the outlet and use the box as a junction box to wire the HPWC in a more traditional manner, although you may be required to add a cutoff switch near the HPWC in that case (the plug acts as the local cutoff when using a plug).
mknox
Well-Known Member
Being the "belt and suspenders" kinda guy I am, I already installed a 60 amp disconnect switch adjacent to my NEMA 14-15 in the garage. I didn't like the idea of plugging or unplugging anything into that outlet while powered, especially with the potential of a wet floor in winter conditions when snow/slush drips off the cars.
@mknox I just about have everything ready however I can't seem to figure out where the green cable connects to in the HPWC.
Currently
Black to L1
Red to L2/N
White to ground
Green to ?
I purchased the 4 prong (range cord). Nema cord 50amp 4'ft (black, red, green, white wire exposed.
Help please.
Currently
Black to L1
Red to L2/N
White to ground
Green to ?
I purchased the 4 prong (range cord). Nema cord 50amp 4'ft (black, red, green, white wire exposed.
Help please.
What do I do with the white(neutral) wire?
My mistake.
Black to L1
Red to L2N
Green to ground
White(neutral) to ? (Do I just cap off)
mknox
Well-Known Member
You don't use the white wire, so just cap it off. Technically, the NEMA 14-50 is a 120/240 volt socket, but the HPWC (and most EVSE) are just 240 volts. The neutral is needed to get 120 volts between it and either the red or black wires.
Dstrohl
Member
For what its worth:
From: FAQ: Home Tesla charging infrastructure Q&A
CAN I ATTACH A CORD AND PLUG TO MY HPWC AT THE 50A SETTING?
In several threads on this forum, some have asked whether they may use their HPWC plugged into a NEMA 14-50 receptacle; this would allow them to unplug it and use their UMC in case of a wall connector failure.
Technically, there is nothing in the NEC that prohibits the practice; Tesla's instructions don't explicitly call for only permanent wiring methods, and article 625 permits 240V devices to be plug-and-cord devices as long as they're "fastened in place". The only restriction is that the segment of cord prior to the ground fault protection (HPWC) must be a maximum of 12 inches in length (NEC 625.17(A)(3)(a)). Proper connectors, clamps, and strain relief connectors must be used.
When consulted on the compliance of such a solution, several municipal and county inspectors have determined the practice to be legal based on the current instructions published by Tesla, and the NEC's requirements.
However, when consulted, Tesla expressed concerns about the practice. The charging team responded to an inquiry with an explanation that the HPWC is designed to be mounted on a wall or post and wired using permanent wiring methods. There are concerns that a power cord could be yanked from the HPWC's terminals and expose live wires if, for example, someone or something grabbed the cord and yanked.
A suggestion was made that Tesla note in the instruction/installation manual that permanent wiring methods are required, which would then be required by the NEC per section 110.3.
In several threads on this forum, some have asked whether they may use their HPWC plugged into a NEMA 14-50 receptacle; this would allow them to unplug it and use their UMC in case of a wall connector failure.
Technically, there is nothing in the NEC that prohibits the practice; Tesla's instructions don't explicitly call for only permanent wiring methods, and article 625 permits 240V devices to be plug-and-cord devices as long as they're "fastened in place". The only restriction is that the segment of cord prior to the ground fault protection (HPWC) must be a maximum of 12 inches in length (NEC 625.17(A)(3)(a)). Proper connectors, clamps, and strain relief connectors must be used.
When consulted on the compliance of such a solution, several municipal and county inspectors have determined the practice to be legal based on the current instructions published by Tesla, and the NEC's requirements.
However, when consulted, Tesla expressed concerns about the practice. The charging team responded to an inquiry with an explanation that the HPWC is designed to be mounted on a wall or post and wired using permanent wiring methods. There are concerns that a power cord could be yanked from the HPWC's terminals and expose live wires if, for example, someone or something grabbed the cord and yanked.
A suggestion was made that Tesla note in the instruction/installation manual that permanent wiring methods are required, which would then be required by the NEC per section 110.3.
mknox
Well-Known Member
Yeah, I'm well aware of that from the FAQ. I am in Canada where the rules are largely harmonized with the US, but there are some subtle differences.
I do wonder one thing about this 12" rule since I don't have a copy of the NEC: Is this specific to EVSE only? They seem to sell these somewhat longer cables in the US just like in Canada, and presumably they allow longer cords on stoves and dryers. I'm hard pressed to see what the difference is between one appliance connected to a NEMA 14-50 and another.
You can always cut the Home Depot cord set down to 12" if this is a concern. I didn't.
Dstrohl
Member
Well, I know that cords are covered in several places, but the specific reference this is from is:
- 625: Electric Vehicle Charging System
- 17: Cords and Cables
- A: Power Supply Cord: The cable for cord connected equipment shall comply with all of the following
- 3: Have an overall length as specified in 625.27(A)(3)a. or b. as follows:
- a: When the interrupting device of the personal protection system specified in 625.22 is located within the enclosure of the supply equipment or charging system, the power supply cord shall be no longer than 300mm (12") long.
- b: When the interrupting device of the personal protection system specified in 625.22 is located at the attachment plug, or within the first 300mm (12") of the power supply cord, the overall length of the cord shall be a minimum of 1.8 meters (6') and shall be not greater than 4.6 meters (15')
- 3: Have an overall length as specified in 625.27(A)(3)a. or b. as follows:
- A: Power Supply Cord: The cable for cord connected equipment shall comply with all of the following
- 17: Cords and Cables
BTW, this is from the 2017 NEC (NFPA 70: National Electrical Code®) which you can access for free (after registering).
DaveWaterloo
Member
When I had my HPWC installed, I insisted that it be plugged into a newly installed NEMA 14-50. (just in case I moved, I wanted the option of taking the HPWC with me). Ontario, Canada.
The Electrician insisted that the ground had to "face left/right side" and I asked him to show me the code where it did say "must face a side" or similar.... I said great I wanted to face the "top side" (I didn't want an unnecessary turning radius) . And it just seems safer to not have gravity working against you. The electrician opined that the inspector would not approve it.... so I asked can we give him a call? The inspector said he was ok with it.
The Electrician insisted that the ground had to "face left/right side" and I asked him to show me the code where it did say "must face a side" or similar.... I said great I wanted to face the "top side" (I didn't want an unnecessary turning radius) . And it just seems safer to not have gravity working against you. The electrician opined that the inspector would not approve it.... so I asked can we give him a call? The inspector said he was ok with it.
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mknox
Well-Known Member
That is virtually identical to my setup, right down to the armored cable feeding the NEMA 14-50. The only difference is that I opted for a 60 amp disconnect switch beside the outlet and had it mounted higher on the wall. I was worried about plugging/unplugging while live... especially while standing on a potentially wet garage floor.
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