Class 2 and Class 1 wires for Tesla Wall Connector and Neurio active energy monitor

[Alexis]

Hello!

I install a lot of Tesla wall connectors and Tesla recommends to use Neurio active energy monitor controller for applications like apartment building panels where it adjusts output based on usage.

I'm having a lot of issues with them passing inspections. As I expected just had another inspection for another installation and new set of issues arised. Inspector said that this device is "illegal". Even though he couldn't answer when I asked him how he passed these installations in the past.

Now got a "fail" for mixing class 1 and class 2 wiring. Inspector said that this device is illegal because :

A. CTs wiring (by Generac btw) are rated 300V and couldn't be in the same enclosure.

B. My com low voltage wire can't run in the same conduit as high voltage wire to the charger.

C. Tap conductor ground wire must be sized to the main wire ground size. 100A apartament breaker/feeder, my tap to the sub panel is #6 and #10 ground. He said that my tap ground to the sub panel has to be also #8?

He also didn’t like that Neurio energy monitor is located in the same enclosure of the panel.

I followed instructions from Tesla. Here is their installation/commissioning video:

I believe Neurio is made by Generac. Could anyone please help me to figure out the best way to approach this? Or this is actually illegal and all installations containing there for solar, powerwalls, generators are actualy illegal?

 

[jaggedben]

Now got a "fail" for mixing class 1 and class 2 wiring. Inspector said that this device is illegal because :

A. CTs wiring (by Generac btw) are rated 300V and couldn't be in the same enclosure.

You can use Class 1 conductors in the same conduit or enclosure as power and lighting. You cannot do this with Class 2. So where I see CL3R cable in the conduit with power conductors that's definitely a violation. I can't tell if your other cable is Class 1 listed because that would require seeing documentation beyond the markings on the cable.

The idea that all wiring in the same enclosure must have the same voltage rating is a common misunderstanding. All 300.3(C) says is they all must have a rating equal at least to the maximum circuit voltage. So if the power wiring here is 120/240 then 300V rated wire is fine.

So he is at least partially correct here. Looks to me like you have a violation although perhaps not for exactly all the reasons he said.

B. My com low voltage wire can't run in the same conduit as high voltage wire to the charger.

Since you used the CL3R cable he is correct. You would be permitted to upgrade that com wiring to a Class 1 wiring method, but that likely won't preserve your RS-485 coms functionality. Also the code justification is pretty into-the-weeds and might not be worth it with this inspector. So maybe just run your CL3R outside the conduit.

C. Tap conductor ground wire must be sized to the main wire ground size. 100A apartament breaker/feeder, my tap to the sub panel is #6 and #10 ground. He said that my tap ground to the sub panel has to be also #8?

He is correct on this.

He also didn’t like that Neurio energy monitor is located in the same enclosure of the panel.

I followed instructions from Tesla. Here is their installation/commissioning video:

Tesla should know better. They know better with Powerwall where they instruct you to use a listed Class 1 cable for the coms. I can't speak to the Neurio instructions and such. On the fine points it may be okay to have the energy monitor in the panel, but it's not necessarily good practice and would be probably be more legit to stick in a separate junction box. I can't speak to whether Neurio's instructions on what cabling to use and where to run it are legit. A lot of times it seems like such companies just avoid saying anything about code violations that the installer would be likely to commit when following the instructions. Like, it's okay to run Class-2 cable into certain enclosures with power wiring, but not in the same conduit.

I believe Neurio is made by Generac. Could anyone please help me to figure out the best way to approach this? Or this is actually illegal and all installations containing there for solar, powerwalls, generators are actualy illegal?

Probably if you look at the fine points of the instructions they are not all completely illegal, and with some adjustment could be made legal. I'm not here to defend Tesla and it wouldn't surprise me in the least if many details of their instructions weren't completely code compliant. Especially past versions.

 

[jaggedben]

Some threads that may be worth reading around these kinds of issues:

0-10 inside the same conduit

Hi, I understand that class 1 and class 2 wiring cannot be installed in the same raceway without a barrier but I'm wondering if I were to use #12 AWG THHN for both the high voltage (120V) and the 0-10 dimming controls if that would be code sufficient? I don't see why not but that's why I'm here

forums.mikeholt.com

CT wiring and conductors

What Class of wiring would the CT conductors or cables used to monitor PV system be considered? Are they Class 1 or 2? Something else? I’ve seen some in Cat 6 cable in same raceway as power wiring and some with actual 600V conductor insulation in raceway with power conductors. In what manner can...

forums.mikeholt.com

UL listing and 110.3B

Does UL listing and UL recognition both satisfy NEC 110.3(B) requirements? We have a massive amount of cable that is UL recognized and CSA listed. But not UL listed. Sent from my iPhone using Tapatalk

forums.mikeholt.com

 

[NoahsArc]

Where did you get your Neurio from? Tesla was not selling them to retail last I checked (1mo ago).
I was preparing to install one, when I realized I couldn't source one of the model specifically called for by the charging unit instructions.

I was planning to fish the cable free air. I wouldn't mix it in a conduit either.

 

[Alexis]

You can use Class 1 conductors in the same conduit or enclosure as power and lighting. You cannot do this with Class 2. So where I see CL3R cable in the conduit with power conductors that's definitely a violation. I can't tell if your other cable is Class 1 listed because that would require seeing documentation beyond the markings on the cable.

The idea that all wiring in the same enclosure must have the same voltage rating is a common misunderstanding. All 300.3(C) says is they all must have a rating equal at least to the maximum circuit voltage. So if the power wiring here is 120/240 then 300V rated wire is fine.

So he is at least partially correct here. Looks to me like you have a violation although perhaps not for exactly all the reasons he said.


Since you used the CL3R cable he is correct. You would be permitted to upgrade that com wiring to a Class 1 wiring method, but that likely won't preserve your RS-485 coms functionality. Also the code justification is pretty into-the-weeds and might not be worth it with this inspector. So maybe just run your CL3R outside the conduit.



He is correct on this.



Tesla should know better. They know better with Powerwall where they instruct you to use a listed Class 1 cable for the coms. I can't speak to the Neurio instructions and such. On the fine points it may be okay to have the energy monitor in the panel, but it's not necessarily good practice and would be probably be more legit to stick in a separate junction box. I can't speak to whether Neurio's instructions on what cabling to use and where to run it are legit. A lot of times it seems like such companies just avoid saying anything about code violations that the installer would be likely to commit when following the instructions. Like, it's okay to run Class-2 cable into certain enclosures with power wiring, but not in the same conduit.



Probably if you look at the fine points of the instructions they are not all completely illegal, and with some adjustment could be made legal. I'm not here to defend Tesla and it wouldn't surprise me in the least if many details of their instructions weren't completely code compliant. Especially past versions.

Thank you so much for such a detailed responce!
I will either run low voltage outside the conduit or replace it with 2 strands of 14awg then..

Could you also please advice about AIC rating for the breaker?
The current apartment breaker rating is 22,000, I installed 65 for the 50A. They require me to install main breaker with hold down kit for the panel and then out breaker (so 4 space panel), but neurio needs another 15 or 20A breaker, so I need to install a quad 20/50 and I don't think those come with 22,000 rating.. I've heard that there is a series rated chart which can be used that may help to get some of the breakers lower in the rating? Are there any devices to lower this rating downstream? As now I have another inspector flagging DCC device for only having 22,000 rating, installed by 65,000 panel..

Thank you!!

 

[Alexis]

Where did you get your Neurio from? Tesla was not selling them to retail last I checked (1mo ago).
I was preparing to install one, when I realized I couldn't source one of the model specifically called for by the charging unit instructions.

I was planning to fish the cable free air. I wouldn't mix it in a conduit either.

I'm a Tesla approved installer, so I can purchase them directly, not retail. But I have to buy more of them at once and it is not really much cheaper..

 

[NoahsArc]

I'm a Tesla approved installer

Makes sense then. How much of a hassle was that?