Cruisair issue

[myisland]

We have a 18k cruisair reverse cycle a/c unit on our boat. Right now you hit cool and here a standard click from the unit (if memory serves me right we have always heard that click when the unit turns on) and about a second later a second click about 1-2 seconds later. The unit then appears to run but not pushing cold air and draw is only 2 amps. No air messages at all. We turn to heat and it seems to push heat.

In the past few months if the power dropped below 120v at all we would get lo ac message ad the unit would shut down. Also yesterday before the unit started not working right we powered off the unit at its control head and did the same to our rear ac unit and the water pump">raw water pump did not turn off. So after a while i turned the breakers off to the two units and the pump and to turn it off. Whe turned breakers on again pump works fine, but cant help but think this might be related.

Please if you have any ideas, as it is getting hot enough we really want our ac.

thanks in advance for your help

[sailorchic34]

How old is your shore power cord. I was getting a 10V drop with light load after 5 years. I cut the old shore plug and installed a new one and it was working with 0v drop again.

Could be the control relay messed up, which is my guess, with only 2 amps, the compressor is not running in cooling. So the control relay could have a burnt contact and might need replacing.

Have you checked your water flow???

[myisland]

Thanks for your help,
The shore power cord is only a year old but with bad power and a old boatside plug was starting to show as if it was getting hot on the plug so took the plug off the boat side end and hard wired it into the system and that gave us better power to the boat.

Any suggestions how to check the control relay? i have taken the covers off the two of the cruisair boxes with the unit and the circuit board was in one and looked great, wiring block in the other and it looked like new. someone also said locally a capacitor however i am not sure if it is the units placement or i am blind but i am not seeing anything that looks like a cap.

Water flow is excellent

[AllezCat]

do you have 2 identical units?
if so swap the control stuff around. If it has capacitors for starting -they will be large cylinders - few inches long - couple inches diameter. swap them to other unit. see if there is difference. sounds like the compressor is tripping on thermal overload - unfortunately may be seized - but if very lucky may be control item or low voltage from bad connection.
If works on heat - make sure is from compressor and not electrical booster element (if any) - and would be REALLY hot now...

Goes without saying you would have licensed electrician do this...

[sailorchic34]

The capacitor may be located on or adjacent to the compressor. Probablt 3-4 inches line and round or oval. Before touching it, and with power off (breaker in off) ground out between the two connections with an insulated handle screwdriver. Do not touch the capacitor till you ground out the charge.

[sailorchic34]

Its probably not a locked up compressor or capacitor btw as your amp load would still have been high. 2 amps when running says its a bad connection or control relay So your looking for the control relay, Should have the tstat wires connected to it

[AllezCat]

Originally Posted by sailorchic34

Its probably not a locked up compressor or capacitor btw as your amp load would still have been high. 2 amps when running says its a bad connection or control relay So your looking for the control relay, Should have the tstat wires connected to it

"and about a second later a second click about 1-2 seconds later"
this is indicative of it locked up - drawing high amps - and tripping on the thermal overload.
If there is an amprobe on the compressor leads - it will show high amps then nothing when it trips.
I am assuming the 2 amps is read from typical boat amp display - and is from fan/pumps only...
but it could be anything...

[sailorchic34]

Could be. Having a helper turn the AC on while watching the amp load should show that bump for the lock rotor. A high voltage drop would cause the overload to trip too. Maybe change the high limit/ overload out as sometimes they go bad.... Or could be the capacitor as that would have similar effect.