Solar Utility required disconnect

[DerrickM]

Hi,

I know that the utility required disconnect is not required in all states and not by all utilities. But it is where I live. And I also know that it's not NEC required.
My question is this:
I am running a 3 phase 480 volt sub service to an outside panelboard dedicated to solar pv circuits from Enphase micro inverters. Before I head down the long hallway to the outside of the building, I need to first come out of the 480v supply panel and head in the opposite direction so I can mount a disconnect within 10' of the utility supply meter. This will require me to run my #2 conductors and 1 1/4 pipe to this disconnect and all the way back to where I started, thus adding a lot of additional wire, pipe and man hours.
Has anyone seen or done this type of thing but instead of this way, could I use my supply breaker as a shunt trip and wire the utility disconnect to it that way?
I would still meet the requirements of the utility having a visable, electrical load break, labeled disconnect within 10' of their meter, and save $1000's on wire, pipe and man hours.
Would this shunt trip situation not do the same thing as the line voltage disconnect?
Any thoughts
Thanks,
Derrick

 

[iwire]

Shunt trips do not generally meet the utility requirements in my area.

They require a disconnecting means with a 'visible break' which means a typical safety switch that you can open the door and see that the circuits are open.

 

[DerrickM]

Thanks for that.
I needed to get my head around it.
You are correct, it does say a visible load break in the utility literature, so a disconnect switch with line conductors it is.

That said, it must be very costly in some applications to do this on larger commercial buildings where your meter is so far away from your equipment panel etc.
Now I am starting to understand why people are fighting this and saying it is unnecessary when most times emergency responders pull the meter anyway.
But on some commercial buildings with CT's on the mains, pulling the meter does not do anything.

Thanks
Derrick

 

[Carultch]

Thanks for that.
I needed to get my head around it.
You are correct, it does say a visible load break in the utility literature, so a disconnect switch with line conductors it is.

That said, it must be very costly in some applications to do this on larger commercial buildings where your meter is so far away from your equipment panel etc.
Now I am starting to understand why people are fighting this and saying it is unnecessary when most times emergency responders pull the meter anyway.
But on some commercial buildings with CT's on the mains, pulling the meter does not do anything.

Thanks
Derrick

With special permission, sometimes they allow you to have it somewhere other than outside, as long as it is 24/7/365 accessible with the assistance of building staff. One application of this is a high rise building, where it is impractical to bring the conductors all the way downstairs.

Also, the reason they claim have this requirement is not for emergency responders to the building, but for utility workers to shut off during line work to confirm that it is de-energized and will not backfeed. UL1741 already covers this for most if not all inverters, but utilities require it as a "belt and suspenders" solution.

 

[jaggedben]

I think it's really a conversation you need to have with the utility.

I guess if you're lucky enough to have someone post details of how they did it, you could take that to your utility and ask them 'can we do it this way?' But the answer will really depend on who you're dealing with.