Powerwalls coming soon but first install wall charger

[njmurvin]

My SGIP Powerwalls (2) are coming soon and so is my used Model X. So I need to get busy and get a wall charger installed. I have about 100 ft run to the wall charger location from my panel. I plan to put a j box at about the 75 ft mark where it enters the garage. If I want to install it for the highest output (48 amp charging) on a 60 amp circuit, can I get away with #6 THHN or do I have to use #4.? I plan to run a neutral while I’m at it in case it’s needed in the future.

 

[jjrandorin]

This appears to me to be a wall charger installation question, and would likely get more feedback in one of the vehicle subforums for battery and charging than here. I am also not an electrician, and no where near one of the experts on this topic in this particular subforum.

With the above being said, I am fairly sure that #6 THHN (in conduit) would be fine for a 60amp dedicated charging circuit (which would charge at 48amps continuous). The concern I would have is, is that wall connector figured into the plans that whomever is processing your SGIP powerwalls already has likely permitted?

It doesnt sound like it was part of the existing loads when you started (especially if you are getting them "soon"). 60amp may not fit into your backup loads panel along with everything else that needs to go in there, especially if it was not accounted for in the design.

You might have the option to leave it on the non backup loads panel side, but you might want to know that this is something you may need to consider.

 

[wwhitney]

#6 Cu has a 75C ampacity of 65A, so as long as you avoid 60C only wiring methods (NM cable, UF cable, LFNC), it's fine for a 60A circuit for a 48A continuous EVSE. Although #4 Al would be cheaper, and while the EVSE may have copper only lugs on it, if you have a junction box anyway, you could switch from Al to Cu there.

Also, I checked the voltage drop and the Southwire calculator say 1.8% (of 240V) for 48A on 100 ft of #6 Cu. Which is fine.

Cheers, Wayne

 

[njmurvin]

I’m a little confused about the installer’s status. They seem to want to deliver the PWs now but install them later. I have had just one site visit and so much was left up in the air at that point, I don’t believe a permit could have been pulled yet. I’ll get a status update next week before I proceed.

 

[BGbreeder]

I’m a little confused about the installer’s status. They seem to want to deliver the PWs now but install them later. I have had just one site visit and so much was left up in the air at that point, I don’t believe a permit could have been pulled yet. I’ll get a status update next week before I proceed.

Personally, I'm skeptical of contractors doing abnormal things.

Do you really want to be responsible for the Powerwalls before installation? I could see an awful lot of finger pointing if something goes sideways. Drop of for an install the next day? Sure. Drop off for an install at unknown date? I wouldn't do it.

All the best,

BG

 

[njmurvin]

Well, I requested a pause on the delivery but the PWs arrived on Tuesday anyway (communication error?). Install to commence in 10 days (at least that's what's scheduled). Ironically, the PWs have been the bottleneck. Now that the contractor has received a slew of them, they don't seem to have the technicians available to install them.

 

[njmurvin]

Getting back to running the circuit to my wall charger. Is there any limit to the number of J boxes that can be in the circuit? I'd like to put one near the sub-panel where the circuit originates. Also, I'd like to put another where it goes through the stucco wall and enters the garage.

My plan is to do all the wiring myself up to the sub-panel and have the installers take it the last 4ft or so between the J box and the sub-panel. I should have mentioned in my first post that this sub-panel is existing and the entire panel will be treated as a backed up load as part of the main panel/gateway installation. I prefer not to have the car charge during backup power, but my understanding is that that can be managed separately.

 

[wwhitney]

Getting back to running the circuit to my wall charger. Is there any limit to the number of J boxes that can be in the circuit?

No, but unless there's a reason for one (like transitioning from an indoor only wiring method to an outdoor only wiring method), the expectation for a quality job is zero. One's fine if it makes the job easier.

I prefer not to have the car charge during backup power, but my understanding is that that can be managed separately.

I understand yes, if the car is a Tesla.

Cheers, Wayne

 

[CrazyRabbit]

Run a sub panel to garage…. Then wire the charger.

 

[BGbreeder]

Or use an LB connector...