New control cabinet question

[1carwash1]

Refurbishing a pumping plant and need to update the existing control panel/box. The panel will house the transformer, motor starters, etc. The panel will be attached to the side of the plant frame similar to National Pride’s setup. Does the control panel need to be NEMA 3R or will a 1R be sufficient? I Would like to add a cooling fan and that would defeat a 3R panel designation.
Also, since I’m starting from scratch, should I opt for one large transformer or use one for each bay? For those of you that have done this before, any suggestions or tips would be appreciated? If you could also post some pictures of your cabinet layout that would be helpful too. Thanks

 

[MEP001]

NEMA type 1 doesn't even have a seal, but you could probably add a gasket and make it mostly moisture- and dust-proof. I don't think you need a fan. I like to keep all electrical boxes closed up tight. The normal humidity in an equipment room is enough to cause things to rust. I would use type 12 at minimum. I've built lots of equipment and have always used type 12.

I much prefer individual transformers for each bay. The single large one doesn't seem to be an issue as long as it's big enough, but I'd always worry that if it fails the whole wash is down until I can get another, and they're not easy to get in a rush. Imagine what it'll cost to ship a 30 pound block of metal UPS Red and pray it doesn't show up damaged. It's also a bit easier when you can flip a breaker for a bay and have everything for it dead.