Line-side Interconnection for Large Commercial Building

[Xixarro]

Hello everyone,

I would greatly appreciate your guidance regarding an interconnection I'm planning for a large commercial building. Here are the specifics of my setup:

• Input line: 7 parallel sets of 600 kcmil feeding into a 2500A CT cabinet
• Solar system output: 3 parallel sets of 250 kcmil

I'm considering a Supply-side connection utilizing available lug spaces at the CT cabinet.

I'd like your opinions on:

• Is this a viable approach using the spare lug spaces?
• Would you recommend using a splitter box instead?
• If so, what would be your recommended implementation method?

Any insights from your experience with similar installations would be greatly appreciated.

Thank you in advance for your expertise!

 

[ggunn]

Using those spare lugs is certainly a viable connection method - electrically, anyway - but the utility may or may not allow it. Some I have encountered will not allow any wiring besides their own in their CT cans.

 

[electrofelon]

Using those spare lugs is certainly a viable connection method - electrically, anyway - but the utility may or may not allow it. Some I have encountered will not allow any wiring besides their own in their CT cans.

Which of course makes no sense. If they do have an issue with this, one workaround may be to just say you are putting in an additional service disconnect per 230.40 ex #2.

 

[electrofelon]

M y preference in order would be

Hello everyone,

I would greatly appreciate your guidance regarding an interconnection I'm planning for a large commercial building. Here are the specifics of my setup:

• Input line: 7 parallel sets of 600 kcmil feeding into a 2500A CT cabinet
• Solar system output: 3 parallel sets of 250 kcmil

I'm considering a Supply-side connection utilizing available lug spaces at the CT cabinet.

I'd like your opinions on:

• Is this a viable approach using the spare lug spaces?
• Would you recommend using a splitter box instead?
• If so, what would be your recommended implementation method?

Any insights from your experience with similar installations would be greatly appreciated.

Thank you in advance for your expertise!

Is this CT cabinet stand alone or is it a metering section in a switchboard? Connecting in the CT is easy of allowed. Second choice would be trying to connect before the service disconnect if lugs can be added/changed/stacked to land 10 conductors.

 

[MyCleveland]

Using those spare lugs is certainly a viable connection method - electrically, anyway - but the utility may or may not allow it. Some I have encountered will not allow any wiring besides their own in their CT cans.

In doing this...does the PSDM switch now become a Service disconnect also?

Is not the point to capture what is going back to the grid and this is now lost?

 

[ggunn]

Which of course makes no sense. If they do have an issue with this, one workaround may be to just say you are putting in an additional service disconnect per 230.40 ex #2.

But as we all know, POCO rules do not need to make sense to the rest of us. One POCO I remember would not even allow us to open their locked and tagged CT can to look at what was inside it.