Manual Transfer Switch sizing for roll up generator

[dummycheck]

I'm working on a project where the client would like to explore adding a connection point for a roll up charger. The current setup new 1600A, 480V service entrance switchboard with (4) sets 600KCMIL per phase. We are considering a service entrance rated generator docking station with a MTS ahead of the 1600A switchboard. I'm trying to think about what size to make this.

For these gen docking stations with MTS, it looks like there is a cut off point at 1200A and once you go bigger than that (up to 1600A) you have to look at getting multiple sections or other inconvenient setups.

They're not sure on what generator size they'd be able to provide, but if they're looking at something like the CAT XQ600 600kW/750kVA I would think that I only need to size the docking station at 1200A {750kVA/(480V*1.732)=902A; 902A*1.25=1127A} as long as it can support my (4) 600KCMIL per phase, right? Is there something else I should consider for this? Do I NEED a 1600A MTS to match my switchboard?

 

[d0nut]

You should match your switchboard size. If you needed 1600A for your switchboard size when it was the service, you will need a 1600A docking station. The same logic that sized the switchboard would apply here. If you go smaller than 1600A, then logically you would reduce the switchboard to match the docking station size.

This docking station sizing is about more than just the generator they would rent during an outage. It will set the service size for your building when on utility power as well.

 

[hillbilly1]

Usually when you get up to that size, a Kirk key system is used. Instead of changing out the service for a service rated switch, get with the manufacturer to add a section at the end of the gear if you have room, and tie to the existing buss just like adding another section. If you don’t have room, a lug kit can be added to the gear, and treated as a tap. Since it’s manual, you don’t need a section as big as the main. Install the Kirk key interlock on both breakers, and you’re good to go.

 

[zbang]

Side note-
I wonder...
how many companies build something like this but neglect to have a contract with the generator rental house to actually get one when they need it.
don't plan for a hole in the wall for the incoming feeders.
(if my math is correct) that's a MW-sized generator, and needs a little more than a single parking space.

 

[hillbilly1]

Amazon, Walmart and other big players snatch up a lot of them. Walmart has a yard full of them that they own.