690.12(C) Initiation Device Outside or Outside wall

[darunedefig]

Code states: "690.12(C) Initiation Device. The initiation device(s) shall initiate the rapid shutdown function of the PV system. The device “off” position shall indicate that the rapid shutdown function has been initiated for all PV systems connected to that device. For one-family and two-family dwellings, an initiation device(s) shall be located at a readily accessible location outside the building."

Normally we install our main solar disconnect, rapid shutdown, on the exterior wall of the building the solar is going on next to a utility meter.
I have a job where installing on the exterior wall is inconvenient and the utility meter/MSP are remote 100'+ away.

Our AHJ in NY is saying "a rapid shutdown initiating device would be required on each of the buildings where the arrays are installed". I asked for where this is in the code and they sent me 690.12(C).

If I am inside the building and I walk "outside the building" and I walk 20' or 100' away then I would still be "outside the building".
If the code wanted the initiation device for rapid shutdown to be on the exterior wall of building or within 20' of the building then they should have said so.
What is everyone else's interpretation of this?

We have done plenty of jobs where placing the disconnect on the exterior wall was close to impossible and instead we had the rapid shutdown device on an exterior post mounted backboard within 10' of the utility meter and over 10' from exterior wall.

I have a job coming up where the house has solar modules and the detached studio/apartment has solar modules. There is a remote meter and main service panel on a post mounted backboard off of the driveway on the way to the house and studio. There is an existing trenched rigid metal conduit from the inside of the studio to the remote meter. Plan is to run DC in metallic conduit inside the building to the SolarEdge inverters located on the same post mounted backboard as the utility meter and MSP. The studio is covered by windows on the lower level with no wall space. I think the main PV AC breaker located by meter or the SolarEdge inverters would follow the code without needing a disconnect at the studio or one for the house. The post mounted backboard by the driveway is readily accessible in my opinion. Maybe if the post mounted backboard was in the middle of the woods or 1000 ft away then that could be considered not readily accessible.

 

[jaggedben]

In my opinion the AHJ is basically correct but also there is a big difference between 20' away and 100' away. I agree there's a gap in the code as far as stating how close the RS switch needs to be to the building, but it's disingenuous to argue that it can be any distance away. 'Within sight' would be a sensible rule, which the NEC defines as not more than 50ft. If I can walk around perimeter of the building (or buildings if all within 50ft of each other) and find a rapid shutdown disconnect for all buildings then I think that should suffice. If I can't, then as much as I might be complying with the letter of the code I can't honestly argue I'm complying with the spirit.

Also think about how you would comply with 690.12(D). The more diligent you are about clear signage the more leeway you may get on where the RS switch can be or how many you have to install.

 

[solarken]

690.12(D) in 2023 NEC and 690.56 in 2020 NEC specifies the location of the RSD label be at each service equipment location, with the label indicating the location of the Rapid Shutdown switch. I agree the code states that the RSD switch just needs to be outside at a readily accessible location. The label is what needs to be located at the service equipment.

 

[ggunn]

I'm confused; isn't the service disconnect the RSD initiator for a SolarEdge inverter, or is the PV system supply side interconnected? Does the AHJ want a separate RSD initiator for each building?

Also, is the AHJ OK with PV modules on one building feeding an inverter on the other? Some that I have dealt with would not allow it.

 

[jaggedben]

690.12(D) in 2023 NEC and 690.56 in 2020 NEC specifies the location of the RSD label be at each service equipment location, with the label indicating the location of the Rapid Shutdown switch. I agree the code states that the RSD switch just needs to be outside at a readily accessible location. The label is what needs to be located at the service equipment.

That section also says the lable can be "at an approved readily visible location".

 

[jaggedben]

I'm confused; isn't the service disconnect the RSD initiator for a SolarEdge inverter, or is the PV system supply side interconnected? Does the AHJ want a separate RSD initiator for each building?

While I could be wrong (I don't recall explicit documentation from Solaredge and never carefully tested in the field), I believe a DC disconnect that isolated the wiring on a separate building would comply with RS requirements for that building because the optimizers would reduce voltage to the controlled limits.

Also, is the AHJ OK with PV modules on one building feeding an inverter on the other? Some that I have dealt with would not allow it.

I guess you work with a lot of AHJs who make up rules that aren't in the NEC.

 

[ggunn]

I guess you work with a lot of AHJs who make up rules that aren't in the NEC.

That never happens, does it?

 

[jaggedben]

That never happens, does it?

Not outside of Texas.

 

[ggunn]

While I could be wrong (I don't recall explicit documentation from Solaredge and never carefully tested in the field), I believe a DC disconnect that isolated the wiring on a separate building would comply with RS requirements for that building because the optimizers would reduce voltage to the controlled limits.

I remember in the early days of RSD and SolarEdge we had to install bleed resistors in the DC lines because the voltage did not get down quickly enough when the DC was disconnected from the inverter.

 

[darunedefig]

Directory label, showing where the disconnects would be located in my example, would be on the main service panel or utility meter that are next to each other. If there was a fire then the fire fighters would find the main service panel next to the utility meter to shut off site power and there would be the directory explaining that the solar AC disconnect located next to the MSP would be the rapidshutdown for the solar.

I wish there wasn't that gap in the code and we didn't have to guess at the spirit of the code. From your comments I will only lightly fight with the AHJ on this and go with the 50' from building recommendation. I will put DC disconnects on or within 10' of the buildings for this job.

 

[jaggedben]

I remember in the early days of RSD and SolarEdge we had to install bleed resistors in the DC lines because the voltage did not get down quickly enough when the DC was disconnected from the inverter.

Right but IIRC that issue was on the inverter side not the array side. It was needed to keep the capacitors in the inverter from energizing the DC conductors when you wanted to initiate RS with an AC disconnect. I never really understood why it was necessary if the DC disconnect on the inverter could be the RS switch. But it was good for when the inverter was inside and the service was outside.

(Hopefully I'm not misremembering.)

 

[Zee]

Solaredge has "Automatic Rapid Shutdown upon AC grid disconnect".
Where did you tie the solar inverter output circuit into, the MSP or a sub panel (SP)?
If you tied into a SP, I am not clear where all the sub panels and MSP are that you feed upstream through toward the grid.......... but it seems that any of the breakers - including existing sub panel feeder breakers and PV breaker - can be labeled and used as an RS initiating device.