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THHN and 4/3 Romex availability

kbmoon

Member
Aug 10, 2021
56
39
Seattle
Ok so trying to get the final consensus here. Got my wall connector and wanted to fully utilize the charging capabilities with 60amp but having a hard time finding 4/3 romex by the foot or 6/3 THHN wiring. I'm almost just thinking of taking a hit and doing 50amp with 6/3 romex because of its availability. What does everyone think? Is there a source you recommend?
 

jebinc

EndlessVibrating PLAID, cream/FSD; MYP, wht on wht
Supporting Member
Jun 19, 2019
8,584
12,737
Seattle area
Ok so trying to get the final consensus here. Got my wall connector and wanted to fully utilize the charging capabilities with 60amp but having a hard time finding 4/3 romex by the foot or 6/3 THHN wiring. I'm almost just thinking of taking a hit and doing 50amp with 6/3 romex because of its availability. What does everyone think? Is there a source you recommend?
Home Depot
 

Sophias_dad

Active Member
Supporting Member
Jul 29, 2018
1,884
2,093
Massachusetts
finding 4/3 romex by the foot or 6/3 THHN

There really isn't 6/3 THHN, btw. THHN Wire • Same-Day Shipping — Wire & Cable Your Way has THHN by the foot, and you really only need 2x#6 and 1x#10(ground) for the HPWC. They also have 4/3 NMB, but no longer publish prices for it. If you are doing NMB, consider doing /3 anyway because you might want a standard outlet there someday.

And yeah, Home Depot or Lowes likely sells these, except for 6/2 NMB.
 

MY-Y

Active Member
Mar 4, 2020
1,236
1,411
MD
Check your local electrical supply house. I ran 4/3, but 4/2 is also fine for a wall connector. If you can run conduit, 6 gauge THHN should be available by the foot as well. 6/3 MC is another good choice for in-wall and is likely sold by the foot online or at your local electrical supply house as well.
 

dhrivnak

Active Member
Jan 8, 2011
4,530
3,960
NE Tennessee
I have 6/3 as I wired NEMA 14-50 plugs for each bay. We never have really had the need for more so we are happy with the NEMA 14-50. It is easy to transfer from house to house and new owners likely prefer a NEMA 14-50 as you can use it for an EV, but also welders, RV's or most any other 240 appliance.
 
Ditto the other responses here - I got 8 gauge THHN from Home Depot and ran it through ¾" PVC conduit to a 50A breaker. I'm on a EV charging program with my electric CoOp that only allows charging between 11pm and 7am and I've never had an issue with the car not being fully charged. 8 gauge is cheaper and easier to pull, too.

If you really want 50A charging then either a supply house or the online site mentioned above would be your best bets.

A couple of tips - 6g wire is quite expensive so I'd run your conduit, then take some string and run it through to measure how much you need before ordering. Check with your electrical inspector ahead of time about requirements. If you do an outlet, they may require a GFCI breaker. Code also requires wire to be run in conduit 'where susceptible to damage.' That's open to interpretation, but my inspector required conduit in the garage.

Edit: corrected wire gauges
 
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Sophias_dad

Active Member
Supporting Member
Jul 29, 2018
1,884
2,093
Massachusetts
6 gauge THHN from Home Depot and ran it through ¾" PVC conduit to a 50A breaker
That's kinda curious, #6 THHN is fine for a 60 amp breaker and 48 amp charging(should you ever want to). I actually have #6 NMB, a 50 amp breaker, and STILL run 48 amp charging(technically not allowed)
 

Stevedore

Member
Aug 8, 2021
28
21
NJ
I'm in the process of installing my wall connector now, & went with #6 THHN in PVC conduit, 60 amp breaker. My run was only about 30 ft with very few bends, so pulling the wire was relatively easy. I got the THHN at Lowe's. ($1.31/ft) Home Depot had it on their website, but the local store was out of it.

I overdid it, either out of extra caution or (more likely, ignorance), and used #6 for the ground wire as well. I could have used smaller, saved a few $$ and made the pulling easier, but it's done now.

I got a permit & having it inspected when I'm done, and hoping not to get nailed for some minor infraction, like the wrong type of conduit clamps, wrong conduit connectors, or whatever. Even if I need to re-do something, I'm still saving a ton of $$ compared to what an electrician would have cost. My total materials cost is less than $200.
 
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kbmoon

Member
Aug 10, 2021
56
39
Seattle
I'm in the process of installing my wall connector now, & went with #6 THHN in PVC conduit, 60 amp breaker. My run was only about 30 ft with very few bends, so pulling the wire was relatively easy. I got the THHN at Lowe's. ($1.31/ft) Home Depot had it on their website, but the local store was out of it.

I overdid it, either out of extra caution or (more likely, ignorance), and used #6 for the ground wire as well. I could have used smaller, saved a few $$ and made the pulling easier, but it's done now.

I got a permit & having it inspected when I'm done, and hoping not to get nailed for some minor infraction, like the wrong type of conduit clamps, wrong conduit connectors, or whatever. Even if I need to re-do something, I'm still saving a ton of $$ compared to what an electrician would have cost. My total materials cost is less than $200.
Glad to hear. I have about 11 ft of run from where I want to place mine and the electrical panel is inside the garage and on the same wall as the point of installation. Coat for electrician to come out for what seems like a straight forward installation is outrageous but I get the peace of mind to pay for it.
 

rjpjnk

Active Member
Mar 12, 2021
1,010
621
NJ
fwiw, I actually prefer to run the Wall Charger at 40 Amps even though it can go to 48 if needed. The reason is even at 40 Amps the car is fully charged many hours before I wake up next day. What's the hurry? The lower current keeps things cooler.
 

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