Originally Posted by f1100turbo
True you can do what she said.
But you cannot install a 50 amp ems with only 30 amp service.
You don't have the appropriate wiring nor enough hot wires.
"Sabre owners united"
It doesn't sound like he's doing a hardwire. Sounds more like he's looking for a plug in kind. In that case, plugging a 50 amp into 50 amp service, then using a 50-30 adapter to power the rig should be perfectly fine.
On the other hand, if he's looking to go 30-50 then a 50, then a 50-30 it might still work, but could really depend on exactly how the EMS handles being on a 30-50 adapter. I haven't heard stories on here yet about issues with a 50A EMS on a 30-50 adapter and I'm sure there must be some guys running 50A rigs who park in 30A serviced sites from time to time so I doubt there'd be much of an issue.
My only concern is where he said he wanted to use a Y to power a second AC unit he has wired up to a separate 30 AMP line. In that case, putting it on a 50 amp service, then using one of those adapters that splits the two legs into a 30 receptacle and a 20 amp receptacle, usually only provide 25 amps to both. So he's basically reduced his 30 amp trailer to running on only 25 amps with this approach. (Actually the same could probably be said of the first approach as I though 50-30 adapters just tap one leg.)
All in all, I'd say the best option would have been to upgrade his rig to 50 amp service to handle the 2nd AC instead of putting it on it's own line and then buy a 50A EMS.