240v Charger Installation Advice

[StoicKiwi]

I've had my S P85D for about a year now and I've been on the fence about how to set up a good 240v charging solution. My wife wants to get a Model Y sometime in the near future so, with the 30% federal tax credit coming back, I thought now would be a good time to look into it.
Unfortunately, I'm getting some really mixed messages from electricians down here and was hoping you all could give me some advice.

Preface:
1. I'm no stranger to electrical work but I'm not a licensed electrician so I want everything to be above board and call an electrician to comply with local laws (local law dictates that you cannot do any electrical work unless you're licensed)
2. My home has an 80A subpanel in the garage with space enough for a 240v breaker; an easy run to make (~20ft)
3. My main panel is allll the way on the other side of the house, diagonally
4. I already have 2 Gen2 Wall Connectors

Here are the quotes that I've received from different companies:
(All of these quotes are to set up a new circuit and load-sharing on a 50A breaker between the two wall connectors)

Electrician 1:
$2,400 - This price assumes I remove the panels in the garage and expose the studs
(I think this is some insane pricing for drilling some holes in studs and running some wire 20ft)


Electrician 2:
Said load-sharing is a violation of NEC code and he won't do it. He said he could install a 240v 30/30 tandem breaker and power both wall connectors independently from that.
$900 - My subpanel isn't rated for tandem breakers and he also argued with me on whether or not my dryer outlet was a 10-30 or 6-30 outlet so I don't really trust this company that much....


Electrician 3:
Says local code says all 240v circuits must come from the main panel except dryers and all 120v circuits must come from the subpanel in the house.
$3,000 - $5,000 - To run a dedicated 100A subpanel to the garage to supply the feed and load-sharing to the wall connectors

So as you can see, I really don't know who to trust or how to proceed given the wide range of pricing and advice I've gotten here.
I looked into the code that these guys were talking about and found:

NEC says load-sharing is allowed:

625.42 Electric Vehicle Supply Equipment Circuit Ratings
Former 625.14 has been revised and relocated to 625.41 as a result of Article 625 being reorganized. A new last sentence that includes provisions for an automatic load management system has been added to 625.41. The maximum electric vehicle supply equipment load on a service and feeder shall be the maximum load permitted by the automatic load management system. This revision provides relief from service upgrades in some cases, but an automatic load management system has to limit the load on the service to its capacity.​

Local Code says 120v should be located inside but doesn't mention 240v being outside only anywhere:

408.30 General. All panelboards shall have a rating not less than the minimum feeder capacity
required for the load calculated in accordance with Part III, IV, or V of Article 220, as applicable.
Panelboards containing the 120 Volt branch circuits serving the interior of one- and two-family
dwelling units shall be located in the interior of the structure in a readily accessible location for new
construction.​

To be honest, I'll live with 120v if it is going to cost me $3k to charge more quickly.
Any advice or suggestions are greatly appreciated!

 

[rhumbliner]

local law dictates that you cannot do any electrical work unless you're licensed

I’m not sure that’s correct. I’ve never heard of any jurisdiction where the homeowner is not allowed to do his own work. You’d have to comply with local electrical codes and I would strongly advise you take out a permit and have your final work inspected.

Looking over the electrical code for Bexar County (Bexar County, TX - Official Website) it’s clear you can perform your own work. Even if you’re in the city limits of SA I would guess you can perform your own work.

Of course, this all assumes you live in a private residence, and not a multi-family dwelling, condo, or apartment.

 

[StoicKiwi]

I’m not sure that’s correct. I’ve never heard of any jurisdiction where the homeowner is not allowed to do his own work. You’d have to comply with local electrical codes and I would strongly advise you take out a permit and have your final work inspected.

Looking over the electrical code for Bexar County (Bexar County, TX - Official Website) it’s clear you can perform your own work. Even if you’re in the city limits of SA I would guess you can perform your own work.

Of course, this all assumes you live in a private residence, and not a multi-family dwelling, condo, or apartment.

Thanks for looking into that, I hadn't looked too much into the county site before!

I thought that too and I'm not sure if this is Bexar county specific or what, but I saw these on the city of San Antonio's website:

I also asked every electrician who came out to verify and they all said homeowners can't do any electrical work at all. I didn't know if this was just them protecting their business or not.
One electrician did mention that you could apply for an Electrical Maintenance Technician license that would let you do things like replace fans and receptacles, but not adding circuits or anything in-depth unfortunately.
(Yes, I do live in a private residence as well)

 

[paulk]

What circuits are in that sub panel? I can’t imagine it’s just for the door openers and lights.

 

[Rocky_H]

Wow, you are getting some weird responses from the electricians. I may give guy #2 a benefit of the doubt that he didn't understand what the sharing part meant. If he wasn't listening properly and thought it was just "sharing", like you have them both on the same circuit and just promise not to run them at the same time, then yeah, he would be right, that that doesn't fly. But the smart current control from the two linked wall connectors is exactly designed for this kind of installation, so it obviously does pass code.

And no, there shouldn't be any kind of restriction of 240V circuits having to come directly from the main panel. That's nonsense. If you've got an 80A subpanel in your garage, then you can split off however much you need from that, providing it fits within the allowed load calculations, etc. for whatever else is running from that. So maybe you could only do a 40A circuit from that instead of 50A? You'd need to have that checked.

 

[StoicKiwi]

What circuits are in that sub panel? I can’t imagine it’s just for the door openers and lights.

It honestly is pretty much every light in the house except one room (that was an addition). The only 240v circuit in the subpanel is the dryer (the electrician said they "make exceptions" for dryers), everything else is 120v household stuff, lights, outlets, fridge, washer, etc.
Oddly enough, there is a TT-30 outlet outside the garage as well...

Wow, you are getting some weird responses from the electricians. I may give guy #2 a benefit of the doubt that he didn't understand what the sharing part meant. If he wasn't listening properly and thought it was just "sharing", like you have them both on the same circuit and just promise not to run them at the same time, then yeah, he would be right, that that doesn't fly. But the smart current control from the two linked wall connectors is exactly designed for this kind of installation, so it obviously does pass code.

And no, there shouldn't be any kind of restriction of 240V circuits having to come directly from the main panel. That's nonsense. If you've got an 80A subpanel in your garage, then you can split off however much you need from that, providing it fits within the allowed load calculations, etc. for whatever else is running from that. So maybe you could only do a 40A circuit from that instead of 50A? You'd need to have that checked.

Yeah that is what I was thinking too with guy #2. I explained to him what it was and he sounded like he knew what I was talking about but just said he couldn't do it.

I'm glad you sanity checked me with the 240v breaker thing on #3, I was absolutely blown away by that. When I called him out on it and asked why none of the other guys mentioned this, he said, "Not everyone follows code, some people just do it the easy way." If this were actually the code for some reason, I wonder if the Wall Connector could do 120v? Even 4.8kW would be better than 1.9kW from a 5-20 outlet, though I don't think the Wall Connector can.

I did the load calculations and I think I'd be fine with 50A but if it needs to go down to 40A, that's better than 16A @ 120v for sure!

 

[Rocky_H]

Oddly enough, there is a TT-30 outlet outside the garage as well...

Side note, you can get an adapter plug for a TT-30 from EVSEAdapters if you need it, but the better option if you're not really using the TT-30 for a camper is to just repurpose those wires to a 240V 30A circuit with a 6-30 outlet on it. But obviously you want to do your dual wall connectors instead.

I'm glad you sanity checked me with the 240v breaker thing on #3, I was absolutely blown away by that. When I called him out on it and asked why none of the other guys mentioned this, he said, "Not everyone follows code, some people just do it the easy way."

OMG! What an ass!! Running 240V branch circuits from subpanels is done all the time in every state. It is completely normal and absolutely code compliant.

If this were actually the code for some reason, I wonder if the Wall Connector could do 120v?

It has never been set up for that, so I don't think it's possible. Maybe someone has gotten it to work,but there's no reason for it, because voltage is just not a limitation in a building wiring situation like this. Capacity is always about the amps you can run, and the wiring thickness is always scaled to the amps as well, so if you could run a certain wiring run for a 120V circuit, you could really just do a different type of circuit breaker on that same wiring run and have it be a 240V instead.

 

[brkaus]

How are your already existing WC wired in?

 

[StoicKiwi]

Side note, you can get an adapter plug for a TT-30 from EVSEAdapters if you need it, but the better option if you're not really using the TT-30 for a camper is to just repurpose those wires to a 240V 30A circuit with a 6-30 outlet on it. But obviously you want to do your dual wall connectors instead.

I actually have that adapter from EVSEAdapters and have used it before to great success! haha
I'm wondering if I could get someone to even repurpose that #10 TT-30 run and make it into a load-sharing setup. That would probably be the cheapest, most effective run.

It has never been set up for that, so I don't think it's possible. Maybe someone has gotten it to work,but there's no reason for it, because voltage is just not a limitation in a building wiring situation like this. Capacity is always about the amps you can run, and the wiring thickness is always scaled to the amps as well, so if you could run a certain wiring run for a 120V circuit, you could really just do a different type of circuit breaker on that same wiring run and have it be a 240V instead.

Exactly, no reason to do it at all, which would make a stupid theoretical local code like "no 240v in subpanels" even more ridiculous. How is running 2x 50A 120v circuits "safer" than 1x 50A 240v circuit?!

How are your already existing WC wired in?

Currently, they are mounted on the wall and not hooked up haha
I've had one for a while now but recently got one on eBay right before they became scarce.

 

[brkaus]

Currently, they are mounted on the wall and not hooked up haha
I've had one for a while now but recently got one on eBay right before they became scarce.

We're almost even. I have one installed and wired. One still in a box for about a year - but I have plans
(I have an S, 3, and now an older leaf for the kiddo - the leaf is starting to make this urgent

I see no issues with putting WCs on the sub-panel as long as it has adequate capacity in terms of space and wring to the panel.

 

[TMeister]

JIC you didn't know, tesla has a recommended list of contractors. It's a few clicks to find but here's the direct link Find an Electrician

I would think any of those guys would know what you are talking about. They may be a better choice given that they should be up to speed on EVSE installs.

You could certainly go and file a permit with the city to really find out what the rules for being a contractor are. It depends a lot on licensing rules for the trades. Here, anyone can simply declare themselves for many of the trades. Things like being a hairstylist require a long process, go figure. But plumbing and electrical work not so much. We even have mechanical retail stores that are happy to tell you exactly how to do something to code. And the inspectors here are really nice and helpful and let you fix things right as they are there.

For what you describe, the costs are going to be around $100 or less. So all of your estimates are really out of line. I just installed a 30 ft run in conduit to a 40 amp J1772 EVSE in my son's garage. He has an i3. I spent around $60 on wire, flex conduit, clamps, and a circuit breaker. We built an open EVSE from the kit and direct-wired it in.

 

[StoicKiwi]

We're almost even. I have one installed and wired. One still in a box for about a year - but I have plans
(I have an S, 3, and now an older leaf for the kiddo - the leaf is starting to make this urgent

I actually had an older Leaf before my Model S and it was way easier to charge on 120v with that haha

JIC you didn't know, tesla has a recommended list of contractors. It's a few clicks to find but here's the direct link Find an Electrician

#1 and, oddly enough, #2 actually came from that Tesla approved list, which is why #2 saying load-sharing is against code is all the more insane!

You could certainly go and file a permit with the city to really find out what the rules for being a contractor are. It depends a lot on licensing rules for the trades. Here, anyone can simply declare themselves for many of the trades. Things like being a hairstylist require a long process, go figure. But plumbing and electrical work not so much. We even have mechanical retail stores that are happy to tell you exactly how to do something to code. And the inspectors here are really nice and helpful and let you fix things right as they are there.

I would do this, but unfortunately the only folks who can get permits down here are licensed contractors (which is the pickle I'm in). I checked into it and it looks like I can't even get a blanket license for general contracting and have it work, it HAS to be an electrician's license, which requires OTJ training, classes, etc.
I don't understand why it matters who does the work if the inspector says it looks fine, but I guess that's what they want.

 

[JPoldo]

StoicKiwi said:
"I would do this, but unfortunately the only folks who can get permits down here are licensed contractors (which is the pickle I'm in). I checked into it and it looks like I can't even get a blanket license for general contracting and have it work, it HAS to be an electrician's license, which requires OTJ training, classes, etc.
I don't understand why it matters who does the work if the inspector says it looks fine, but I guess that's what they want."

Your local permit codes are absurd. It sounds like they are trying to protect licenced contractors. I would not accept this arrogant behavior.

As an EE and fairly knowledgeable on NEC, I did a self-install like Tmeister for under $100. It works perfectly. No inspection.

However, if you decide to go with a licensed contractor, consult the inspector first to find out what he will accept. If he rejects what your electrician has done, undoubtedly you will have to pay more for the fix. Beware. I ran into this problem both with electrical and fire alarm inspection.

 

[StoicKiwi]

Your local permit codes are absurd. It sounds like they are trying to protect licenced contractors. I would not accept this arrogant behavior.

Exactly, and I wonder if that has a direct relation to how crazy expensive it seems to even have this simple job done.

As an EE and fairly knowledgeable on NEC, I did a self-install like Tmeister for under $100. It works perfectly. No inspection.

While I like making sure every T is crossed and every i dotted, I'm leaning towards the self-install.
I wonder if I could cheese it and run the cables myself and just have an electrician come to hook up the chargers and just have the cables inspected then...

 

[rhumbliner]

Property owners can get their own permits as long as they can certify they will live or lease the house for 1 year after finishing the project.

This seems like a perfectly reasonable requirement on the part of Bexar County and should be no hurdle for you, right?

I would do this, but unfortunately the only folks who can get permits down here are licensed contractors

This situation is sounding stranger all the time. I’ve pulled my own permits for my residence in Teton County WY and Clark County NV and those counties were more than helpful. In fact, when I showed up to pull my own permit the people behind the counter were especially lenient as to what qualified as architectural drawings and electrical schematics because I was not a professional, licensed contractor. In both cases I talked to the fire inspectors first and got their tentative blessing before going to the county to file for the permit. They helped me with the necessary drawings.

In one instance the permit I applied for included swapping out a 200-amp meter for a 300-amp meter (which necessitated the power utility coming out to disconnect the line to the house), adding a new 100-amp cutoff switch, running a 240v / 120-amp line in conduit to my garage and installing a new sub-panel in the garage. My point is, this was a complex project and the county had no problem with the homeowner doing all of the work.

 

[StoicKiwi]

View attachment 523066

Property owners can get their own permits as long as they can certify they will live or lease the house for 1 year after finishing the project.

This seems like a perfectly reasonable requirement on the part of Bexar County and should be no hurdle for you, right?

Yes, it wouldn't be a hurdle if I were doing building work or another type of work that wasn't electrical, mechanical, or plumbing. The last sentence in that picture is the issue: Only State licensed contractors can get electrical, mechanical, and plumbing permits.

I completely agree and understand with your examples too, back when I lived in Virginia, I would walk down to our county office and pretty much just ask for a permit to run a new circuit or something and sometimes even talk to the inspector beforehand. Being in a small town had some advantages
This problem doesn't look like it is an issue for Bexar county, but rather the City of San Antonio is who has this particular requirement. I've called the local office and asked what I needed to do to get a permit and they straight told me that I couldn't unless I was a licensed electrician.

 

[JPoldo]

"I wonder if I could cheese it and run the cables myself and just have an electrician come to hook up the chargers and just have the cables inspected then..."

You may run into a problem during inspection when asked for a permit. Any electrician you hire to inspect self install may blow the whistle to permits authority resulting in a fine. Consider keeping the project under the radar.
While there is a temptation to use #6-2 (w/ground) b/c Tesla doesn't use common wire, don't do it because next owner of home may need the common line. Go with #6-3 or larger.

You should be able to hook up the chargers too assuming good documentation.

 

[StoicKiwi]

"I wonder if I could cheese it and run the cables myself and just have an electrician come to hook up the chargers and just have the cables inspected then..."

You may run into a problem during inspection when asked for a permit. Any electrician you hire to inspect self install may blow the whistle to permits authority resulting in a fine. Consider keeping the project under the radar.
While there is a temptation to use #6-2 (w/ground) b/c Tesla doesn't use common wire, don't do it because next owner of home may need the common line. Go with #6-3 or larger.

You should be able to hook up the chargers too assuming good documentation.

Thanks for all the input and advice, I was able to get everything installed over the weekend and everything went smoothly! I used 6/3 per your suggestion and connected with polaris 4-14 connectors in a 6x6x4 box. I used some 18/2 shielded, twisted pair cable for the WC to WC connection.

The only modification I did was instead of hard wiring the WCs, I opted for 14-50 outlets for future-proofing and just pigtailed the WCs. I do occasionally hook up 240v equipment in the garage so this'll work well too.

(No judgment on the messy junction-box, I'm going to make it look cleaner eventually )

 

[JPoldo]

Nice job ! Assume the metal cover plate for WC #2 is on order.

 

[StoicKiwi]

Nice job ! Assume the metal cover plate for WC #2 is on order.

Thanks!
Precisely, everything seems to be delayed with this COVID-19 business.