NEMA 14-50 for now but allowing for HPWC later

[swillmac]

Hey Club,

Patiently awaiting my Model 3 and have been looking into home charging stuff.

I want to install a NEMA 14-50 outlet in the garage now and just use the included UMC when I get the 3. The UMC will stay plugged in to this outlet most of the time (save for maybe 3 or 4 roadtrips a year) so I'm not concerned with wear on the outlet. However, if down the road I want to upgrade to a HPWC I want to have the proper wiring so I can just remove the 14-50 and hardwire the HPWC without much hassle.

I've got plenty of room in a 200a panel to install a 50a breaker and run 6 gauge wire. I'll have a 70ish foot run from my breaker (in basement on one side of the house) through the floor joists in the unfinished basement and up to the garage on the other side of the house.

From what I'm seeing, the 14-50 outlet takes 4 wires (2 hots, a neutral, and a ground) but the HPWC only uses 3 (2 hots and a ground). Am I correct in assuming that I can just wire up the 14-50 properly with the 4 wires and then just not use the neutral later for the HPWC?

I'm handy and good at following instructions but I am an electrical rookie. Fortunately I have an electrical engineer friend that is going to help with the install, but he's not a Tesla guy hence why I ask the question here. After searching extensively on both google and these forums, I wasn't able to find an answer to this specific question. Can anyone assist? Thanks in advance.

Ninja edit for another question: The wall where the plug will be mounted is between the garage (no heat or A/C) and the house so the wall is insulated (just regular R-30 or whatever, not foam). Is there any issue running my 6 gauge wire inside this wall as far as a potentially warm wire contacting the insulation?

 

[TexasEV]

Not much reason to change out 14-50 outlet for HPWC if you can't increase the amps you're charging at-- and you won't be able to do that with a 50A circuit. Anyway with even the long range model 3 it doesn't charge at more than 48A, so there's not much benefit to going to the expense of a HPWC. It's more useful for the S and X that have 72A chargers.

 

[dhrivnak]

If you do run a number 6 wire then you could later hard wire and upgrade the breaker to 60 amps. Easy to do. And there could not be a heat issue with the wire. If it gets more than slightly warm you would have a problem. I have run this for 7 years now with no issue.

 

[swillmac]

Thanks for the info. The HPWC later would just be a neater upgrade later if i decide to do it as I’m obviously not needing more than 50a.

Assuming i keep the 14-50 and don’t ever need to upgrade the breaker, can I safely use a smaller gauge than 6 for the run?

 

[miimura]

Thanks for the info. The HPWC later would just be a neater upgrade later if i decide to do it as I’m obviously not needing more than 50a.

Assuming i keep the 14-50 and don’t ever need to upgrade the breaker, can I safely use a smaller gauge than 6 for the run?

In some situations (THHN wire in metal conduit for example) you can run 8ga copper wire, but 6ga has lower resistance so it's better overall for 40 amp charging.

 

[Rik59]

A question from the electrical-ignorant group: can you install a 14-50 plug and then install a HPWC in series, recognizing that you could only use one at a time? The reason for doing this is future-proofing your house for non-Tesla EV guests to charge.

 

[TexasEV]

A question from the electrical-ignorant group: can you install a 14-50 plug and then install a HPWC in series, recognizing that you could only use one at a time? The reason for doing this is future-proofing your house for non-Tesla EV guests to charge.

No.

 

[GSP]

A question from the electrical-ignorant group: can you install a 14-50 plug and then install a HPWC in series, recognizing that you could only use one at a time? The reason for doing this is future-proofing your house for non-Tesla EV guests to charge.

Don't wire them in series, LOL.

You could install a separate breaker for each. If your panel does not have capacity to feed two more 50 Amp circuits, there are inexpensive devices that only allow one of two adjacent breakers to be turned on at the same time.

When guests come, you can switch off your HPWC and turn on the 14-50. However, non-tesla EV owners usually don't have a way to charge from a 14-50, so you may also need to get an EVSE for them to use.

The least expensive solution for guests would be to get a "Tesla to J1772 adapter" from quickchargepower.com. Then guests could use your HPWC or UMC with the adapter.

GSP

 

[Rik59]

Don't wire them in series, LOL.

You could install a separate breaker for each. If your panel does not have capacity to feed two more 50 Amp circuits, there are inexpensive devices that only allow one of two adjacent breakers to be turned on at the same time.

When guests come, you can switch off your HPWC and turn on the 14-50. However, non-tesla EV owners usually don't have a way to charge from a 14-50, so you may also need to get an EVSE for them to use.

The least expensive solution for guests would be to get a "Tesla to J1772 adapter" from quickchargepower.com. Then guests could use your HPWC or UMC with the adapter.

GSP

Thanks. That’s a great solution.

 

[Racerx22b]

Hey Club,

Patiently awaiting my Model 3 and have been looking into home charging stuff.

I want to install a NEMA 14-50 outlet in the garage now and just use the included UMC when I get the 3. The UMC will stay plugged in to this outlet most of the time (save for maybe 3 or 4 roadtrips a year) so I'm not concerned with wear on the outlet. However, if down the road I want to upgrade to a HPWC I want to have the proper wiring so I can just remove the 14-50 and hardwire the HPWC without much hassle.

I've got plenty of room in a 200a panel to install a 50a breaker and run 6 gauge wire. I'll have a 70ish foot run from my breaker (in basement on one side of the house) through the floor joists in the unfinished basement and up to the garage on the other side of the house.

From what I'm seeing, the 14-50 outlet takes 4 wires (2 hots, a neutral, and a ground) but the HPWC only uses 3 (2 hots and a ground). Am I correct in assuming that I can just wire up the 14-50 properly with the 4 wires and then just not use the neutral later for the HPWC?

I'm handy and good at following instructions but I am an electrical rookie. Fortunately I have an electrical engineer friend that is going to help with the install, but he's not a Tesla guy hence why I ask the question here. After searching extensively on both google and these forums, I wasn't able to find an answer to this specific question. Can anyone assist? Thanks in advance.

Ninja edit for another question: The wall where the plug will be mounted is between the garage (no heat or A/C) and the house so the wall is insulated (just regular R-30 or whatever, not foam). Is there any issue running my 6 gauge wire inside this wall as far as a potentially warm wire contacting the insulation?

This video demonstrates exactly what I did. No need to change you 14/50 outlet. Just use a range cord hard wired to your HPWC.