Transfer switch(s) commercial

[Moosifer]

I have a customer with what I would call a 500a 240v single phase service. 2qty 200a disconnect and a 100a disconnect all directly fed from overhead power and the meter has CT's.

They want to make sure they can connect generators if power is lost from the next hurricane. We are in Florida.

I have done military setups that are similar but simpler or sometimes a lot more confusing, but plugging in a 100a cord is no big deal.

Can I do three fused double throw switches with 100a plug inputs on them and provide cords for them to connect to whatever generator or generators they can acquire if power is lost for a few days? (I would assume 3x 100a would keep them going).

We have done similar things for walk in coolers. I just don't know if there are rules about a maximum size temporary generator connection.
If it were a 400a service I would tell them they need a single transfer switch and a permanent generator.
This is for a disaster recovery operation so they have access to all sorts of generators and really don't want to buy one that will sit around and do nothing most of the time.

Any help would be appreciated.

 

[Seven-Delta-FortyOne]

You can have a 100 amp input, but if the transfer switch is feeding the entire load after the MCB, the TS will need to be rated the same as the service. So 2 x 200 amp and 1x 100 amp transfer switches.

The generator input can be whatever you like as long as it’s no more than the main.

Are they going to have 3 generators on site?

 

[Moosifer]

I would assume they will have 3 generators if they want to run the entire place.
I did plan on 200a rated manual / double throw fused transfer switches. I figured 100a feed into them would be plenty.
I just wasn't sure if there was a NEC rule about cord and plug from a generator since it seems the only temp generator specific connections out there stop at 50a. This will be expensive if I don't do it per code and it does not pass inspection.
I have seen docking stations for $5000 but that seems like overkill.

 

[Seven-Delta-FortyOne]

The larger towable generators have larger twist lock connectors, and you can always use Camlock connectors and SOOW cord.

 

[Moosifer]

The Camlocks are cool. Probably less than 100a pin and sleeve plugs / receps.

Would there be weirdness with multiple generators per floating neutrals and not switching the neutral or would I need to treat them as 3 separately derived systems requiring switched neutrals and ground rods for the generators?
Otherwise the neutrals would be bonded to ground in the fused double throw disconnects/transfer switches so they would be sharing the same neutral which would be tied back to the utility transformer and I imagine unbalanced 120v loads would be energizing the neutral at different times if that matters or causes noise or heat or tears apart the universe.