Splitting Off From Wall Connector Conduit

[rub1k]

First time EV/new Tesla owner here and while trying to decide between merits and tradeoffs of using a Wall Connector vs. Mobile Connector for charging in my garage, I ran across a picture where the conduit to the WC is split off to a (presumably NEMA 14-50?) socket.

I should know better than to ask, but... this isn't/can't be safe and/or up to code, right?

 

[Cosmacelf]

First time EV/new Tesla owner here and while trying to decide between merits and tradeoffs of using a Wall Connector vs. Mobile Connector for charging in my garage, I ran across a picture where the conduit to the WC is split off to a (presumably NEMA 14-50?) socket.

I should know better than to ask, but... this isn't/can't be safe and/or up to code, right?

Sure it can be. You don’t know what wires are run in that conduit, and that’s the important part. You can have two sets of wires for two different circuits in the same conduit. If they shared one set of wires for the receptacle and EVSE, that wouldn’t be to code, but you can’t tell from that picture. Given how neat it looks, I would bet they did it correctly. And the bottom receptacle isn’t necessarily a 14-50, it looks like a regular 120V receptacle to me.

 

[jcanoe]

Back to your question, the Wall Connector is superior to the Mobile Connector for a number of reasons:

1) Supports charging at up to 48 amps (this requires a hard wired 60 amp rated 240V circuit.) Supports charging at 40 amps on a hard wired 50 amp rated 240V circuit. (The Mobile Connector is always limited to 32 amps on a 50 amp rated 240V circuit using a 14-50 or 6-50 receptacle.)
2) Longer 24 foot charging cord versus 18 foot cord for the Mobile Connector
3) Rated for use in all weather conditions, indoors or outdoors
4) Ability to support load balancing when more than one Wall Connector is being used (up to 6 Wall Connectors.)
5) Ability to limit charging to specific Tesla vehicles (by VIN.)
6) Ability to capture, download charging history data from the internet
7) Ability to receive periodic over the air firmware updates from Tesla for new capabilities
8) Has a built-in cable hanger and holder for the Tesla NACS connector. (No separate cable hanger or holder for the connector needed.)

Also, only requires 2 wires (plus ground) and a hard wired connection. Can use a standard inexpensive double pole 240V circuit breaker. (Charging circuits that terminate with a receptacle now require GFCI protection for the receptacle. For 50A circuits that terminate with a 14-50 or 6-50 receptacle this requires the more expensive GFCI circuit breaker.)

 

[rub1k]

@Cosmacelf Thank you. Fair enough and points well made. I can see how it all depends on what wires are in the conduit; I shouldn't have assumed things.

@jcanoe Thank you too for all that great feedback. I think I'm leaning towards the Wall Connector for some of the reasons you've already mentioned. My breaker panel is towards the front-right corner (with car parked head-in) of my garage, so I've got to figure out where to have an electrician run conduit to, but guessing it'll be along the wall, effectively putting the Wall Connector by the front of my garage (still inside). That way, the charging cable should reach to the MY parked inside as well as if I park it outside (will have to figure out how to pass the cable through but I've seen some good ideas on here. The 24-foot length (vs. the 18-foot Mobile Charger) will definitely come in handy.

I've also got to see how much current an electrician will be able to use -- my current panel was recently (~2 years ago) re-done during remodeling but we've added A/C at the time and there's no room for a new breaker. Looks like we'll need a subpanel and we can probably only afford to do a 40A breaker. Sadly, will have to configure the WC for 32A but I'll gladly take the ~30 miles/hour; it should be plenty for overnight charging.

Quick question -- I'm hearing mixed feedback from electricians I'm getting quotes from regarding California electrical code and GFCI breaker requirements. I was positive that GFCI isn't needed for the WC (per install instructions, it has integrated GFCI protection) and I pointed this out with one of the electricians agreeing it's not needed while another swearing that it is since NEC 2023(?) requires it for a lot more things. Also, I thought CA is technically still adhering to NEC 2020 rules (and not yet the newer 2023) but will have to do more research.

 

[jcanoe]

Quick question -- I'm hearing mixed feedback from electricians I'm getting quotes from regarding California electrical code and GFCI breaker requirements. I was positive that GFCI isn't needed for the WC (per install instructions, it has integrated GFCI protection) and I pointed this out with one of the electricians agreeing it's not needed while another swearing that it is since NEC 2023(?) requires it for a lot more things. Also, I thought CA is technically still adhering to NEC 2020 rules (and not yet the newer 2023) but will have to do more research.

I am not an electrician. My understanding is that GFCI is now required on all new EV charging circuits (which must be dedicated, not shared) if the circuit terminates at a receptacle (regardless of the amperage rating of the circuit.) If you install a 240V, 40A or 50 A circuit for charging a vehicle that has a plug, i.e the circuit has a 14-50 receptacle then a GFCI breaker is required. If you install the same 50A circuit in your kitchen for an electric range then you do not need a GFCI circuit breaker. The difference is the electric range is rarely if ever unplugged.

The GFCI at the receptacle or at the breaker is designed to protect the user when plugging or unplugging the EVSE from the power receptacle. This is separate from the GFCI that is built into the EVSE. That GFCI is designed to protect the user when plugging or unplugging the charging cable from the vehicle's charge port. (This built-in GFCI protection has always been part of every EVSE.) When there is no power outlet (receptacle) as with the installation of the Wall Connector then there is no need for a GFCI at the breaker.

Most requirements of the NEC can be traced back to a scenario where people were electrocuted. The latest NEC revision now requires GFCI protection for all outdoor electrical equipment installations. (A child in Baltimore was electrocuted, died, when they climbed over a back yard chain-link fence and while coming down stepped onto the housing of an AC compressor that was not properly wired (the metal housing was electrified.)

This is where things are a little undefined. An enclosed garage is usually considered to be an indoor installation as far as electrical service. (A covered car port that is open on the sides and does not have a garage door would not be considered an indoor installation.) The Wall Connector has GFCI protection so it should not require the GFCI circuit breaker (states this in the Wall Connector installation manual) if installed in a garage.

If you install the Wall Connector outdoors, per the latest revision of the NEC, it is unclear if the built-in GFCI of the Wall Connector satisfies this new GFCI requirement. The Wall Connector mount, housing and cover are not conductive of electricity but any metal conduit leading to the Wall Connector could become electrified due to faulty installation or damaged wiring. Someone could be electrocuted if they touched the conduit or any junction box. A GFCI at the breaker would protect against this risk of electrocution. Home heating and air conditioning manufacturers have been notified that they have several years before outdoor HVAC equipment will require a GFCI breaker.

 

[MattM24]

Sure it can be. You don’t know what wires are run in that conduit, and that’s the important part. You can have two sets of wires for two different circuits in the same conduit. If they shared one set of wires for the receptacle and EVSE, that wouldn’t be to code, but you can’t tell from that picture. Given how neat it looks, I would bet they did it correctly. And the bottom receptacle isn’t necessarily a 14-50, it looks like a regular 120V receptacle to me.

You are right to not assume, but you also have to derate current carrying conductors when you have that many in a raceway.

So, yes, you could have two full circuit in there, but they wouldn’t be very large.

In what you are saying, you might be able to run 6awg to a 50A breaker for the wall connector and 12awg for the 15A breaker due to derating voltage requirements.

If you ran those same wires in different raceways, you could run 60A breakers and 20A breakers.

I would run two different raceways, if this was a concern for me.

I’m not an Electrician though and I don’t know regulations where you are from. Also, my consideration above was only one aspect. I don’t know what else might come into play.

 

[rwiegand]

It seems incredibly unlikely that that little junction box has sufficient fill capacity for the wires involved, but other than that it looks legit. (unless the splice is in the bigger outlet box and the junction is only used as a pass-through, in which case it might also be fine).

 

[Cosmacelf]

It seems incredibly unlikely that that little junction box has sufficient fill capacity for the wires involved, but other than that it looks legit. (unless the splice is in the bigger outlet box and the junction is only used as a pass-through, in which case it might also be fine).

I am saying that I doubt there is a splice. We just don’t know.

 

[MattM24]

It seems incredibly unlikely that that little junction box has sufficient fill capacity for the wires involved, but other than that it looks legit. (unless the splice is in the bigger outlet box and the junction is only used as a pass-through, in which case it might also be fine).

That’s not a junction box. It’s a conduit body.

It’s used to pull the wire through.

 

[rub1k]

<snip>The Wall Connector has GFCI protection so it should not require the GFCI circuit breaker (states this in the Wall Connector installation manual) if installed in a garage.

If you install the Wall Connector outdoors, per the latest revision of the NEC, it is unclear if the built-in GFCI of the Wall Connector satisfies this new GFCI requirement. The Wall Connector mount, housing and cover are not conductive of electricity but any metal conduit leading to the Wall Connector could become electrified due to faulty installation or damaged wiring. Someone could be electrocuted if they touched the conduit or any junction box. A GFCI at the breaker would protect against this risk of electrocution. Home heating and air conditioning manufacturers have been notified that they have several years before outdoor HVAC equipment will require a GFCI breaker.

Thanks again; all very good and useful info that's much appreciated.

And in the case of a setup consisting of 40-50A GFCI Breaker -> proper conduit -> (industrial Bryant/Hubbell) NEMA 14-50 outlet, one should stick to using the Mobile Connector (capped at 32A) and using one of those pigtail cords to power a Wall Connector like in this video isn't recommended, correct? This setup would add the flexibility of having a 14-50 outlet, but I wouldn't trust the cord for continuous load/charging since it looks like it's meant for a range/dryer.

I figure with setting up a Wall Connector, I can always pull it out and terminate to a 14-50 outlet instead (assuming breaker is GFCI, if not, replace breaker) if I'd ever need to so it's still the safest way to go.

 

[jcanoe]

Thanks again; all very good and useful info that's much appreciated.

And in the case of a setup consisting of 40-50A GFCI Breaker -> proper conduit -> (industrial Bryant/Hubbell) NEMA 14-50 outlet, one should stick to using the Mobile Connector (capped at 32A) and using one of those pigtail cords to power a Wall Connector like in this video isn't recommended, correct? This setup would add the flexibility of having a 14-50 outlet, but I wouldn't trust the cord for continuous load/charging since it looks like it's meant for a range/dryer.

I figure with setting up a Wall Connector, I can always pull it out and terminate to a 14-50 outlet instead (assuming breaker is GFCI, if not, replace breaker) if I'd ever need to so it's still the safest way to go.

Adding a power plug to any electrical equipment where the manufacturer does not provide this option or instructions for a plug option is a code violation.

It would also be a code violation as EV charging circuits must be dedicated. If you want two ways to charge you could install a 100 amp sub panel and then two separate 240V 40A or 50A charging circuits from the sub panel.

 

[rwiegand]

That’s not a junction box. It’s a conduit body.

It’s used to pull the wire through.

I know what it is, and the initial impression is that someone might have put a splice in it, in which case it's way too small. Looking closer that seems really unlikely. If the conduit (looks like 3/4") instead has #6 wires for the charger and #12 for the outlet below then it's completely fine.

 

[MattM24]

I know what it is, and the initial impression is that someone might have put a splice in it, in which case it's way too small. Looking closer that seems really unlikely. If the conduit (looks like 3/4") instead has #6 wires for the charger and #12 for the outlet below then it's completely fine.

On a 50A circuit, yes, since with four current carrying conductors, you’d have to derate to 80% of the 65A that the 6awg runs.

 

[EVer Hopeful]

So what did you end up doing? . . .

 

[rub1k]

So what did you end up doing? . . .

Nothing yet, unfortunately. Since I'm working from home, other than the wife driving the MY to work a day or two a week and a short 2-day mini vacation (~350 miles roundtrip), it hasn't been driven as much as expected. Today marks one month since I picked up the car and I think we're around 900 miles on the odometer.

We've been charging (from ~15-20% to ~80-85%) at a nearby supercharger once a week; it helps that it's new/fast and mostly had ~$0.25/kWh pricing.

After talking to a couple electricians, I've pretty much decided that I'm going to have a wall connector installed... and only use it at night since the house has a 70A main breaker at my meter (deep sigh and not paying $10k or whatever to have the service upgraded to proper 2023/200A levels). I'll also have to make sure the A/C doesn't go on at night or that breaker will trip a lot, etc.

So, TWC off a 40-50A breaker and configuring it to only use 32A... and only using it at night to charge the MY. That's what my solution will have to be.