Help Me Confirm the my Tesla Wall Connector is Wired Correctly

[cbdream99]

I had a similar setup and upgrade done last month. I have a Clipper Creek 40 on a 6-50 outlet, 50AMPS breaker. I decided to upgrade to a Tesla wall charger, so I called my Solar installer, that also does electrical work. The salesperson said I could upgrade the breaker to 60AMPS without any issue since they are familiar with existing wiring, but the electrician called first before coming over, saying I will require to upgrade the wire (it's 6AWG inside/no conduit, probably around 25 feet away from the breaker). I don't want to spend that extra money and stay with the 50AMPS breaker and hard wire to the waller charger.

 

[Justjim]

Thanks for all of the comments - they are much appreciated.

I may not have been clear in earlier posts. As an overriding perspective I want to have a fully code compliant charging solution regardless of how I decide to configure the Wall Connector. I want no risk of having something go wrong due to my negligence or lack of knowledge.

My Clipper Creek HDS-40 EVSE became unreliable due to a problem with the pilot wire sporadically losing continuity, as diagnosed by their tech team. That's why I bought the Tesla Wall Connector, opting for the J1772 connector since it will charge both of my cars using the fully approved Tesla NACS to J1772 adapter. If the Clipper Creek didn't have a problem I'd continue using it as is, without upgrading to the Wall Connector.

Since I had to change to the new Connector I decided that it would great if I could increase my home charging speed, which wasn't an option on the Clipper Creek. So I upgraded the circuit breaker to a 60AMP unit. At the time my friend seemed to believe that this would require no new permit since I was merely upgrading the breaker, not installing any new wiring, and he believed the existing wiring was sufficient.

I asked our local power company if there are any rebates/credits for installing new EV charging equipment, and they said "possibly yes", but since I already have an EVSE installed they weren't sure if I would qualify. They suggested contacting their installation team. While doing that I also contacted a local company specializing in EV installation. They provided a tentative quote of nearly $1,400 to remove my old EVSE, mount the Wall Connector and run a new line from the service connection to my home to the panel in my garage (the picture I posted earlier) to fully comply with local code and inspection requirements. I didn't expect such a high quote, and decided to consult my friend, who removed the EVSE, installed the Wall Connector and wired it with the existing #6 wiring and 40AMP circuit breaker.

Following that, he installed the higher 60AMP breaker today, removing the 40AMP breaker and continued to use the existing wiring. To answer an earlier post the current #6 wire cable contains three wires, two white, one black and a copper ground wire. The second white wire isn't connected to the circuit breaker or to the Wall Connector. The black and white wires are connected to the breaker, and the ground wire is grounded in the panel and all of the wires runs directly to the Wall Connector, and are connected as indicated in the Owner manual describing wiring options.

In the original electrician quote the price of dismounting the EVSE and installing the Wall connector was over $800, including $175 for the permit, the rest for the removal/install using the existing wiring/breaker, which seemed excessive to me. I tried to avoid these costs, and did not believe a new permit was needed since the current wiring met code when installed by a licensed electrician.

Now, reading all of your comments, I'm trying to reconsider my initial thoughts and do this correctly. I believe my choices are:

• Use the newly mounted Wall Connector, reinstall the 40AMP breaker, re-initialize it at 40AMPs and be content to charge at 30miles/hour.
• If I upgrade to a 60AMP service it's likely that the existing wiring will not meet code. To replace it will be expensive since the wall will have to be opened, old wire removed, new wire installed.
• Keep the existing wiring, downgrade the breaker to 50AMPs, which appears to meet code, and have about 25% faster charging.

Frankly, I don't need the faster charging, it's merely a convenience and could be useful. My model Y is a 2023 SR AWD, 279 mile range, which meets 95% of my daily travel needs. For longer trips I SuperCharge on the road. At home I normally charge from 20-80%, varying it to 10-90 on occasion, and infrequently below 10-100% to rebalance the battery pack. The faster charging speeds are welcome, but not madatory.

Just to be clear, regardless of the solution I want to be fully complaint will all codes, rules, etc. Saving money is nice, but doing so while violating code/rules is foolish. My initial addition of the 60AMP circuit wasn't meant to avoid code, or create a potentially unsafe condition, it was merely my misunderstanding of the wiring capacity limits. I also don't want to spend nearly $1,000 if it isn't necessary, and that's why I didn't use an electrician initially.

The above is what I should have written initially, but I was in "adrenaline" mode after connecting the 60AMP service, reinitializing the Setup Process, and seeing the car charge at 48AMPS, so my post was inaccurate and not very clear - sorry for the confusion.

There may indeed be some potential rebate for installing an upgraded EV service, but the rules are complex and not very clear about what is required and what the rebate may be. Clearly an electrician would have more information, but surprisingly I've gotten conflicting information from two firms, both recommended by the local power company.

Until I resolve the wiring issues I'm limiting the charging power on the In Car Charge Menu to 40AMPS, to avoid any potential problems.

So, given all that, what is the best path forward?

There are many local code jurisdictions represented here, as well as from both Canada and US having their own national electrial code as well as one post I saw from England that is 240, 50 cycle, so even wire specifications are different! If you want to be sure, call your LOCAL power authority and ask for an inspector to come out. They won't bite your ass for wanting to be safe. In Ontario, the inspection wouldn't even cost anything. They will be able to tell you what you have, what the capacity is and tell you if something should be changed or upgraded.

 

[heavync]

All are torqued to spec 50inch/pounds, if I recall correctly, when initially installed. Everything else followed as instructed. Also beware that the Wall Connector only accesses WiFi through 2.4Ghz connection, not 5G. All wiring mounts comply with guide locations as well.

Out of curiosity what happens if it isn’t torqued to spec? I “assume” my electrician did it right but I don’t know. Is the torque specific to Tesla? Thanks

 

[Tronguy]

Out of curiosity what happens if it isn’t torqued to spec? I “assume” my electrician did it right but I don’t know. Is the torque specific to Tesla? Thanks

Um. I'm an engineer, but electrical; but have been a shade-tree mechanic, including overhauling Ye Random Engine from time to time.

Torque is torque. The idea behind torquing down an electrical connector is to strip off the semi-non-conductive copper oxide and make a real, gas-tight, copper-to-copper bond. The "gas tight" part is important: Keeping oxygen away from metallic atoms keeps oxides from forming.

On top of that, things get hot, things get cold, and one gets expansion and contraction of the metallic parts all over. The torque is meant to fix the metallic parts in position. For the looonnnggg term. That's as true for electrical connections as it is for bolting two halves of a crankcase together: You don't want those nuts/bolts to back out. Goes for lug nuts on wheels, too! In addition to good old metal-to-metal contact, there's assists for this kind of thing: Flat washers, lock washers, lock-tite "glues", and so on.

I'm sure that if I was a true-blue mechanical engineer I could point you straight at reference material and textbooks that state for what materials what torques are required, what thread pitch will do the job, and so on. Me, I'm not in that class: But it's a no-brainer that if there's a torque spec on something, then one had better follow it.

I'm reminded of the gland nut that held the flywheel onto the crankshaft of a VW Beetle engine I once overhauled. 220 ft-lbs of torque. I didn't happen to have a torque wrench in that range, but I did have a 2-ft breaker bar for the socket. Got the crankcase pinned down, got my weight, figured out how far out on the bar I needed to stand, and Stood There. Fun. (There's a joke about that nut: turn it until it breaks, then back it off a quarter turn..,.)

Speaking of that: Overtorquing a fasterner risks stripping the threads, damaging the threads, stressing it so bad that one can't get it off later, and so on.

People who work with screws do have screw-type torque wrenches; one would expect electricians to have them in their tool boxes. Although, with practice, one does get a feel for how much umph a given torque might be. Which is OK, but not for critical parts.

Finally: As one of my hats as general fix-it and testing engineer, I've had cause to shepherd circuit boards and larger systems through various forms of shake & bake. Not just testing what happens when a packed piece of equipment falls off a truck, but the real fun stuff with the earthquake and worse testing. Lack of torque on fasteners (or the correct torque on stuff that, shall we say, wasn't designed with all this 20G in every direction vibration in mind) results in Things Flying Off, not a good outcome. Ha. Back when I summer hired for HP, back when they were test equipment only, I was told by one of the mechanical engineers that they'd get a good crowd in for the shake tests, taking bets as to Whose Part Would Fly Off First . Good times.

 

[kpanda17]

National Electric Code NEC torque rule
110.14 (D)
This doc talks to the 110.14 (D) requirement and gives explaination reason for it

https://www.nema.org/docs/default-source/technical-document-library/using-torque-tools-for-terminating-building-wire4820b20b-e723-4f1d-8863-a491a1fd6f4d.pdf?sfvrsn=b4e9097c_3

SAFE LINK

Torquing and use of copper helps minimize gaps and arcs developing and thus fires

Since the 110.14 (D) became in force, the devices being torqued can handle it based on the updated design

Very important to torque always

 

[IvesSM]

Your handy friend is correct that it depends on the kind of 6 awg wire. The only kind that will support 60amps per NEC is THHN wire in conduit. If you used 6awg NM-B wire (the kind that would need to be stripped) then it would be rated at 55 amps. You should also have a ground hooked up to the wall charger.

Please correct me if I'm wrong but 6/2 MC (Metal Clad) is equivalent to running THHN in conduit and does not carry the same limitations that Romex carries.

Also 6/2 MC is a one-and-done install instead of the 2 step required with Conduit and #6 THHN.

 

[1965Falcon]

Please correct me if I'm wrong but 6/2 MC (Metal Clad) is equivalent to running THHN in conduit and does not carry the same limitations that Romex carries.

Also 6/2 MC is a one-and-done install instead of the 2 step required with Conduit and #6 THHN.

Correct, MC wire is basically "pre-made" THHN wire in metal conduit. Just make sure what you buy has markings on the wires that state it's THHN wire or on the outside somewhere. There is a lot of Chinese MC wire online that has claims that it meets THHN/NEC/UL but then you get it and there are no markings on the wires or conduit and it will fail an inspection (ask me how I know!). It may very well be fine, but I wouldn't risk it.