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I'm trying to add a Level 2 EV charger (EVSE) to my home in the least expensive way possible. The Grizzle-E charger can output 40amps, so I'm planning on supplying it using a 50amp breaker with 6awg THHN wire. My panel is in a relatively convenient basement location to run conduit behind the panel, through the rim joist, and then up the exterior wall to where the EVSE would be mounted. Adjacent to the exterior wall, there is about a 3ft wide flower bed, then the driveway where I would park/charge the EV. The conduit would exit the wall about 18"-24" above the ground, then run 3-4 ft up to the wall mounted EVSE.

I had planned on using 1" LFNC, but then rethinking this due to the requirement that it may not be used in locations subject to physical damage. I've seen this conduit used outdoors for air conditioners, and in my situation, I think its relatively safe from physical damage. However, I'm unsure how this is often interpreted. I understand this is ultimately up to my local AHJ.

Is LFNC typically allowed in this situation? If not, which type of conduit would be a better option?

I'm in NYS under NEC 2017.

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    First you need a load calculation for your panel to see how much extra amps you can use. Unless you have a very long commute, drive a taxi or delivery service, 20 or 30 amps is probably plenty for you.
    – crip659
    Commented Nov 9, 2023 at 22:15
  • > least expensive way possible > 50A breaker For the vast majority of people, 20A circuit at 240V / 4 kW charge rate will suffice. You can run that stuff with cheap 12/2 UF cable protected by a little bit of 1/2" pipe of any kind where subject to damage. Commented Nov 10, 2023 at 23:18

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This is a relatively short distance, so conduit cost is not a big factor. You could use either rigid metal conduit (which looks industrial and stands up to anything and can be the ground as well) or Schedule 80 PVC. 3/4" RMC is large enough for 3 x 6 AWG aluminum wires. You probably only need 2 wires (2 hots, no neutral for most EVSE) and if your EVSE requires copper (or local code requires it) then you would use 8 AWG copper. 1/2" RMC would even work for 2 x 8 AWG copper, but 3/4" would give you flexibility for any future upgrades.

As noted in a comment, you definitely should do a Load Calculation on your total service and, if this is coming from a subpanel, the subpanel too, in order to see how much power you can actually spare for the EVSE. If the answer is at least 20A then provision for that amount (20A, 30A, 40A, 50A - whatever you can get) and call it a day. If the answer is less than 20A then you need to look into either a heavy-up or a load-shedding solution of some sort.

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  • Thank you! So you don't recommend the LFNC, because the other options are superior and still relatively cheap/easy, or because you think my LFNC in my intended use is probably a code violation? Commented Nov 9, 2023 at 23:23
  • I'm pretty sure LFNC is a code violation because of the "subject to damage" aspect. Yes, it is commonly used for HVAC applications, but those tend to be shorter distances and not next to a driveway - probably technically still in violation but so standard that many places effectively allow it. But since the cost is minimal, go for rigid and be done. If this were 100' across the yard to another building it would be a different story. For 100' you wouldn't use LFNC or Rigid - more common would be PVC 40 for the underground and PVC 80 above. Commented Nov 9, 2023 at 23:30

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