Rapid Shutdown for ground mount

[bbartmasse r]

Hello all,

We are installing a new ground mount array into an existing grid tied/battery based system.

The conduit from the array travels about 50 feet before it enters the basement of the home, where it then travels another maybe 100 feet to the charge controller.

My question has to do with Rapid Shutdown. I have read that it does not apply to to underground runs, which makes perfect sense. So where it would start to apply is when it comes into the basement (I think the code allows for up to five feet unprotected in the building).

Are there any specifications on what the "initiator" is supposed to look like and where it should be placed?

can I not have a standard combiner box with breakers that are the "rapid shutdown" in this case. The box would be located on the outside wall of the building.

We have used the fancy gizmos from Midnight when our arrays are on roofs but it seems in this case we would not need one at all?

thoughts?

thanks

 

[Carultch]

Hello all,

We are installing a new ground mount array into an existing grid tied/battery based system.

The conduit from the array travels about 50 feet before it enters the basement of the home, where it then travels another maybe 100 feet to the charge controller.

My question has to do with Rapid Shutdown. I have read that it does not apply to to underground runs, which makes perfect sense. So where it would start to apply is when it comes into the basement (I think the code allows for up to five feet unprotected in the building).

Are there any specifications on what the "initiator" is supposed to look like and where it should be placed?

can I not have a standard combiner box with breakers that are the "rapid shutdown" in this case. The box would be located on the outside wall of the building.

We have used the fancy gizmos from Midnight when our arrays are on roofs but it seems in this case we would not need one at all?

thoughts?

thanks

In 2014, the rule is so vague that you could theoretically place it in your neighbor's attic and still be compliant.

In 2017, they've added more clarity. An outside, readily accessible switch that can either be accomplished by the building's service disconnecting means, the PV system disconnecting means, or a readily accessible switch that clearly indicates ON/OFF (which you might want as a separate unit, if building a battery backup system). Utilities commonly require an outside-mounted open blade switch, and you will often have this switch serve the additional purpose of being the rapid shutdown initiator.

It does not necessarily need to be an open blade switch. Could be a breaker, a mushroom E-stop button, or a rotary switch. In any case, there is a reflective label that is required, and in 2017, there is a diagram required to depict which kind of rapid shutdown rule with which your system complies. Could be a contactor or shunt trip breaker that is remotely activated by any of the above.

 

[jaggedben]

If it's only 50ft, why not just pull AC instead of DC?

EDIT: Nevermind, I reread your post.

 

[bbartmasse r]

In 2014, the rule is so vague that you could theoretically place it in your neighbor's attic and still be compliant.

In 2017, they've added more clarity. An outside, readily accessible switch that can either be accomplished by the building's service disconnecting means, the PV system disconnecting means, or a readily accessible switch that clearly indicates ON/OFF (which you might want as a separate unit, if building a battery backup system). Utilities commonly require an outside-mounted open blade switch, and you will often have this switch serve the additional purpose of being the rapid shutdown initiator.

It does not necessarily need to be an open blade switch. Could be a breaker, a mushroom E-stop button, or a rotary switch. In any case, there is a reflective label that is required, and in 2017, there is a diagram required to depict which kind of rapid shutdown rule with which your system complies. Could be a contactor or shunt trip breaker that is remotely activated by any of the above.

So the initiator could be a combiner panel with circuit breakers in this case? Theoretically.

 

[Carultch]

So the initiator could be a combiner panel with circuit breakers in this case? Theoretically.

Yes. Provided that it is clearly labeled both at the unit, and at any other point one might go in order to initiate rapid shutdown (service meter, service disconnect, etc). I interpret that the 30-second time limit would require that you minimize and group all initiation devices, if there are multiple. So that would prohibit having scattered switches, if it takes longer than 30 seconds to walk among all of them.