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I have a renovation of a hotel to look at tomorrow, the contractor and hotel owner is looking to have two ptac units wired to run off one thermostat in a suite of the hotel.  for the life of me other than I bunch of relays and transformers, I can't think of a way to drive two ptac units with two separate feeds of 24 volts off one thermostat that could provide good operation, relays to isolate one to the other, or simply disconnect one control transformer and feed one ptac from another.  no twinning kits are available and my customer is unreasonable.  suggestions?

Wow, how big is this suite?  As long as both areas being heated are in the same area one thermostat could work.

You would just eliminate one transformer, and run both systems using one transformer and one thermostat.

Download this 1 thermostat / 2 furnaces wiring diagram - Here

You should be fine with one 40VA transformer.  Just jumper the Y terminal from both units if you need cooling. (Not shown on diagram)

The downfall to this setup is if the one transformer fails both systems will not work.

Good luck!

its a small hotel room, but for some reason they are choosing to use two ptacs on one control, I looked at the wiring schematic and thats what I had planned as kinda the only real simple solution.  thanks for the insight, I will see the job tomorrow and post any findings

How did this go, did this take care of your issue?  Also, what brand PTAC units were these?  Not that there should really be a difference on PTAC units, but curious.

Thanks,

FOLLOW UP

Its still in the works and not yet corrected, they are GE ptac units, heat pump units to be exact.  funky little transformer on them with a 208 primary with a 12volt and 24 volt secondary coil, two control boards on the unit, one runs on 12 the other runs on 24.  nothing is ever simple lol