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Discussion Starter · #1 · (Edited)




• Plan to install 240V 6-20R receptacle to left of window (see photo), for portable EV charger, approx 6 ft. horizontal run
• Portable EV charger has built-in GFCI protection - don't plan on using GFCI breaker
• In summer, window is left open - some rain below window is possible
• Existing PVC conduit was installed by Electrician. Not sure if it's Sched 40 or 80. Transition from behind drywall to surface (notch in drywall) seems less than elegant.

Suggestions?
  1. EMT vs Legrand Wiremold 700-series raceway
  2. How to transition from knockout in panel behind drywall to surface
  3. Route raceway above window (avoid rain), or below (shorter). Replace existing PVC conduit with larger diameter EMT to run 2 separate feeds.


Notes
  1. Installing NM cable behind drywall seems time consuming but looks professional. Other EVSE installs I've seen use EMT conduit. A friend worked in a machine shop, so he could help me with EMT piping.
  2. I read that conduit from service panel needs to connect from above (not sure of source). (a) Does it make sense to mount an electrical box on the drywall, adjacent to the panel, to feed the wires from below to above surface? (b) I saw one video where the installer cut a rectangular area above the panel, and replaced it with a wood panel screwed to studs, with holes in wood for connectors.
  3. There is an existing feed in PVC conduit. Does each feed need to be in its own raceway? I don't think there is another knockout to the left of the one used for existing PVC conduit.
  4. Will inspector have an issue with not having GFCI breaker, for garage receptacle? NEC talks about requirement for GFCI only for 125V; not sure if 240V is considered 2x 125V legs for that discussion.
 

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I think straight across below the window would be your easiest route.

As for top panel entry, that could be a local requirement. Since it's a receptacle, a GFCI may be required. The only way to know for sure is to check with your AHJ.

Transition: You'll need some 1/2" BX, a couple of straight connectors for the BX, your wire and Wiremold boxes.
1. Remove a 1/2" knockout in the bottom of your panel. Check the flexibility of 1/2" BX from the removed knockout to determine where to locate your surface-mount box below the panel. The BX can loop down inside the wall and come back up to
2. Take an appropriate length of BX and install the connectors (connector nuts removed). Pull enough wire through the BX to reach from the bottom of the panel to the most distant point in the panel (then pull some more) and tape up the ends of the wires you pulled through the BX.
3. Locate the box base on the drywall and install appropriate anchors (no masonry anchors) to mount the base as level as possible. Making sure you leave plenty of drywall around the anchors, cut a hole in the drywall. Feed the taped end of the wire through the hole and through the knockout into the panel. Slide a connector nut over the wire in the panel down to the connector and tighten the nut.
4. Slide the base over the wire onto the connector, then install the nut and tighten. Mount the base.
5. Using a level, install the Wiremold raceway and secure with straps. Mount the box for the receptacle.
6. Since I worked alone most of the time, I would make a three-sided "funnel" from the wall of a plastic milk jug and put it in the end of the raceway to keep from skinning the insulation while pulling into the raceway. Feed the other end of the wire through the raceway to the receptacle base. I would suggest looping the wire inside each cover to provide slack for some unknown future event that would otherwise make you want that slack (it's easier to make it shorter later).
Now work your way from the receptacle back to the panel, mounting and connecting devices/covers/etc. Once in the panel, connect the ground and neutral (if used). Only then will you make the connections to the breaker. Test and reinstall the panel cover.


Good luck!

 
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Sorry for being verbose. I wouldn't think there would be a problem with a little water as long as the wires have a W in the "wire type" to denote waterproof. Need to remove some insulation from the ground wire in the first box and bond it, grounding the raceway system. I forgot that! :vs_whistle:
 

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Discussion Starter · #5 ·
... The only way to know for sure is to check with your AHJ.

I checked with the inspector - no GFCI required for my application.

Other thoughts:

  • Considering using 10 AWG wire instead of 12 for the 20-amp circuit, since it will be drawing 16 amps continuously for 10 hours charge.
  • Considering adding a 2-pole switch in the box, to control the 6-20R. Use 31 cu. in. capacity box for receptacle, switch, and 10 AWG wire.
 

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I checked with the inspector - no GFCI required for my application.

Other thoughts:

  • Considering using 10 AWG wire instead of 12 for the 20-amp circuit, since it will be drawing 16 amps continuously for 10 hours charge.
  • Considering adding a 2-pole switch in the box, to control the 6-20R. Use 31 cu. in. capacity box for receptacle, switch, and 10 AWG wire.
Why waste the money on #10?

The #12 is rated for 30 amps and will have no issues with the 16 amps.

It will not pull the full 16 amps for the full 10 hours.

The switch is a waste of money also.
 

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Discussion Starter · #7 ·
Why waste the money on #10?

A. 10-AWG would allow upgrading to higher amp circuit in future, for faster charger if needed, without re-wiring, [replacing breaker and receptacle, of course]. For 10' run, cost difference seemed small compared to labor.
B. EVSE consumes energy when not charging (idle). Also, with EVSE switched off, would there be better protection against transient voltage than if at idle? There is no surge protection.
 

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A. 10-AWG would allow upgrading to higher amp circuit in future, for faster charger if needed, without re-wiring, [replacing breaker and receptacle, of course]. For 10' run, cost difference seemed small compared to labor.

OK, I didn't know you might be considering an upgrade.


B. EVSE consumes energy when not charging (idle). Also, with EVSE switched off, would there be better protection against transient voltage than if at idle? There is no surge protection.
If you are that worried, just turn the breaker off.

See my answers in red.
 
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