Add digital thermostat to manual rooftop unit?

[GordonThree]

Thinking of a heavy duty contactor just off the circuit breaker, rather than messing with the wiring in the rooftop unit itself.

Pro; easier wiring location, simple to uninstall

Con; no separate fan control, more inrush turning fan and compressor on together

Thoughts, suggestions?

[time2roll]

GordonThree wrote:
Thoughts, suggestions?

Keep procrastinating. Keep this on your list when you trade RVs.

[GordonThree]

My TT was not pre-wired for a higher end rooftop unit, so the only wire going up there is the 12 gauge power supply.

I thought about an SSR but wondered about having somewhere to put a big heat sink, or if I would need a big heat sink.

I had though about replacing the ceiling module with one designed for an external thermostat, which breaks out the various functions into something a simple thermostat can control, but by the time I got around to doing that, summer would be over and I'd procrastinate until next year.

[RLS7201]

I did that mod to my 95 Bounder.
You will get tired of listening to that mechanical contactor going clunk clunk clunk clunk.
I elected to use Solid state relays in the AC. I have complete control of all functions from the thermostat.
Fortunately my RV had 6 small control circuit leads from the AC to the circuit breaker panel. Didn't have to run wires through the ceiling.
If you elect to try the solid state relays. Spend the extras $$ for a 50 amp relay or better for the compressor. The back EMF imposed on a smaller relay, when turning off, will make it fail.


Richard