Charging Solutions for 120V service

[Rocky_H]

I don't think code allows you to run Romex in conduit due to heat dissipation concerns.

Yes, you can--that's a common misconception.

I am not an electrician but my semi-in-depth research on this is that code DOES allow romex in conduit but nobody should be doing it. The reason people mostly want to put Romex in conduit is to run it outside or in a garage or some other location considered a "wet" location. Code does not allow Romex in "wet" locations even if it's in conduit.

Wait a sec. That doesn't make sense. I get that it's not allowed exposed in wet locations, but then it would need to be inside the conduit to make it not exposed in the wet location. So I am pretty sure that romex inside the conduit would be fine for along the surface of a garage wall.

I am very interested in this, because I plan to do a mixed wire run like this. My current circuit is just a 14-50 outlet a few feet directly below my panel. Since it was straight down, no need to go across studs in the wall--just poke the Romex straight down. But I want to replace it with a wall connector now. That is going to go higher and to the right on the wall surface, and I don't want to have to cut out a section of the sheet rock and drill through studs to run it sideways, so my plan was to get a longer segment of Romex, go straight down through the wall again to the place where the outlet was, and then come out into flex metal conduit to run sideways and up to where I will mount the wall connector. I was pretty sure that would be code compliant to run Romex part in wall and part in conduit.

 

[Pilot1226]

That sounds good. Another option I am considering if I can do it and the wiring is there, I may:

Expand the garage outlet if it is a 20A wiring and breaker (have to check later) and then mount an exterior 5-20 outlet with Taymac box a few feet away.

or there is the exterior 5-20 or tt-30 option as well which will cost more money.

Exterior run would be in conduit outside so sounds like they have to be the THHN type wire. Yes I’d probably ask for 10 gauge wiring either way for resistance benefits. It would probably be a 10-15 foot run for the external option compared to the other side of the garage where it would be closer to like 50 feet after going up across and down the garage.

I will try to take some pictures later to show what I’m talking about.

Also need to figure out a way to build or buy an enclosure to hide the bigger part of the mobile connector so it doesn’t get rained or snowed on.

 

[gfunkdave]

Wait a sec. That doesn't make sense. I get that it's not allowed exposed in wet locations, but then it would need to be inside the conduit to make it not exposed in the wet location. So I am pretty sure that romex inside the conduit would be fine for along the surface of a garage wall.

I am very interested in this, because I plan to do a mixed wire run like this. My current circuit is just a 14-50 outlet a few feet directly below my panel. Since it was straight down, no need to go across studs in the wall--just poke the Romex straight down. But I want to replace it with a wall connector now. That is going to go higher and to the right on the wall surface, and I don't want to have to cut out a section of the sheet rock and drill through studs to run it sideways, so my plan was to get a longer segment of Romex, go straight down through the wall again to the place where the outlet was, and then come out into flex metal conduit to run sideways and up to where I will mount the wall connector. I was pretty sure that would be code compliant to run Romex part in wall and part in conduit.

Short answer: I really don't know, this is all conjecture on my end at this point. I did a little more looking around and maybe you're right. But what I did find nearly universally is that everyone says Romex is a real pain to run in conduit and it's much easier to run individual wires if you're using conduit. They take up less space, too, which allows for better cooling and lower conduit fill considerations. You could also use MC/armored cable, which is pre-made and has all the wires in it. Just buy a reel and cut to size.

I agree that when you step back it doesn't make sense since the conduit would protect the cable from water and being tugged/cut. On the other hand, conduit doesn't necessarily prevent water ingress. A friend ran 1" PVC underground between two buildings, and was very careful about cementing the sections together. When I opened a cover to fish a network cable through it was still full of water. Not the same as in a garage, but still worth remembering.

 

[Rocky_H]

Short answer: I really don't know, this is all conjecture on my end at this point. I did a little more looking around and maybe you're right. But what I did find nearly universally is that everyone says Romex is a real pain to run in conduit and it's much easier to run individual wires if you're using conduit. They take up less space, too, which allows for better cooling and lower conduit fill considerations. You could also use MC/armored cable, which is pre-made and has all the wires in it. Just buy a reel and cut to size.

But this is my problem, and I don't know what is a good solution, because it's a run that is partly inside the wall and then transitions outside the wall. Wire in conduit would mean I would have to put conduit in the wall, and I'm trying to avoid sheet rock work. I'll have to keep asking and researching.

 

[gavine]

But this is my problem, and I don't know what is a good solution, because it's a run that is partly inside the wall and then transitions outside the wall. Wire in conduit would mean I would have to put conduit in the wall, and I'm trying to avoid sheet rock work. I'll have to keep asking and researching.

Can you strip the outer cover on the parts that go in the conduit and keep it on for the parts that are behind walls or where you don't need conduit? Maybe use screw-in clamp connector and a threaded conduit fitting to hold it in place?

 

[Rocky_H]

Can you strip the outer cover on the parts that go in the conduit and keep it on for the parts that are behind walls or where you don't need conduit? Maybe use screw-in clamp connector and a threaded conduit fitting to hold it in place?

Possibly. That's another thing I wouldn't be sure on--if you can have continuous wires that are "Romex" in one part of it, and then are wire in conduit with the rubber sheath stripped off. I'm not even sure if that is allowed.

Maybe this is something where I can pay for an inspector's time to tell me how this job would need to be done.

 

[gfunkdave]

Possibly. That's another thing I wouldn't be sure on--if you can have continuous wires that are "Romex" in one part of it, and then are wire in conduit with the rubber sheath stripped off. I'm not even sure if that is allowed.

Maybe this is something where I can pay for an inspector's time to tell me how this job would need to be done.

You can't strip off the Romex sheath. Romex is sold and licensed/UL rated as the full cable. Even though the individual wires are the same THHN and made in the same factory as THHN they don't have the official THHN (and don't have the THHN/THWN writing on the wire) so they need to stay in the sheath. Practically, it makes no difference because the only difference is they don't have the THHN rating written on them, but an inspector won't allow it.

 

[Pilot1226]

Hmm, I have to figure out which breaker corresponds to my outlets in the garage. In theory, if there's a 20A breaker at the panel for the garage, code would require the wiring to support 20A as well, right? Is there a way to figure out the gauge if I can't see any labeling on the wires?

 

[gfunkdave]

Hmm, I have to figure out which breaker corresponds to my outlets in the garage. In theory, if there's a 20A breaker at the panel for the garage, code would require the wiring to support 20A as well, right? Is there a way to figure out the gauge if I can't see any labeling on the wires?

If there's no labeling on the wires then it's an illegal installation unless it uses Romex because THHN/THWN wiring has to have the "THHN/THWN" on it. If it uses Romex, Romex is color coded. Yellow jacket is 12AWG, white is 14AWG, and orange is 10AWG.

You can confirm the gauge by clamping a wire in a wire cutter's 12AWG sizing hole and seeing if it fits. Careful not to cut the insulation!

 

[Pilot1226]

Thanks, I'll check it out. I'd need 12 AWG for 20A if I remember correctly... This circuit was installed probably 20+ years ago... Let's see...

 

[Pilot1226]

Okay, I have some good news. Apparently, the wiring for the garage is also on the same circuit as the dining room in the house. Some things I checked while the breaker is off:

Dining room has a chandelier with 4 candelabra style LED dimmable bulbs. These bulbs use 3.3W each at maximum intensity.
Wall outlet in shared wall with dining room in living room is also on same circuit. This charges my kid's Chromebook, iPad, and other tech devices (Nintendo/Kindle) but can be moved to a better outlet location on a separate circuit.

Shared wall also has 2 shared sconce-type lights, which have LED's in the standard base. These use 8W each.

Total wattage used for lighting: (3.3*4)+(8*2)= About 30W out of the potential 16A continuous load (of the 20A circuit) at 120V which is 1920W...

Now, the oddball here is if I had something plugged into the outlet like a vacuum. We have Dyson DC-14, so I'm trying to figure out exactly how much amp draw this has. Again, I can use other outlets not on this dining room circuit as needed so this shouldn't be a problem after I talk to the Mrs. I also have the garage door opener on this same circuit. We have a Liftmaster Formula 1 which is 1/2 hp. This appears to be about 5 amps.

Since I am planning to use 120V charging, I am going to be trying to charge this as much as possible. What I'm hoping to do is something like limit the amperage draw to something like 10A during the day for the car, and have it bump up after midnight until 7AM to go to the full 16A as nobody will be vacuuming or going in/out the garage during the night. I'd imagine I'd have to buy a third-party app to accomplish this.

Again, my backup plan would be to run a separate 20A circuit just for the purposes of charging. I could either run this into the garage itself and then figure out a way to snake it out or through to the outside, or just have an exterior run done.

Here are some pictures.



Captions in order:
Panel, labels, garage outlet, side view of garage outlet/junction box, intended area to mount exterior outlet from garage extension, exterior run area, would be near that natural gas relief valve.

Also, just a recap:

1. Would like to change garage outlet from 120V15A outlet to 120V20A outlet as the breaker is a 20A breaker.
2. Would like to consider expanding that garage outlet in photo 3 to go outside and mount an exterior 5-20 outlet on the white wooden frame in photo 4.
3. If 1/2 are not feasible, I would have an exterior circuit run outside from the area generally where the gas pipe relief is to as close as I can get to the edge of the driveway, and use a 5-20 weatherproof box (Taymac). Ideally, I would like to leave the Mobile Connector in as much as possible to reduce wear-and-tear, so I'd like to have some type of enclosure near/next to it that I could leave the MC and cable in between uses, to keep everything out of the weather as much as I could.

 

[Pilot1226]

Starting to wonder if the TT-30 is necessary. While it would provide around 2.3 kW per hour after efficiency losses, it’s only around 800 W more than the less expensive 5-20 option - which would be around 2-3 miles of range gained per hour, or around 20-25 extra per night.

I’d also need to buy the third party EVSE adapter that connects to the Gen2 Mobile Charge which is more expensive than the official Tesla 5-20 one, priced at $75 before tax and shipping.

Also don’t know if the smaller 30 amp breaker is even available on my panel since it shares the same “line” with 2 20 amp breaker (refer to pictures above)... I’m sure the 10 gauge wire is more expensive than the 12 needed for a 5-20 line as well as the receptacle box.



Thoughts?