Cruisair Puzzler Problem

[Quadrille in JB]

I've been working on 2 cruisair units which have various problems.

12000 btu unit-fair water flow, R-22 low side 75 and high side 325, and good air flow but only puts out 70 degree supply air with an 80 deg return. Rotary compressor runs hot. Flushed seawater system and Acid washed condensor heat exchanger but still no change.

16000 btu unit-Great water flow, good air flow, R-22 low side 75, high side 275 deg, 50 deg supply air with 75 deg return. Compressor runs hot and goes off on over temp after about 10 minutes of running, Acid washed condenser heat exchanger but still no change.

I'm looking for ideas on anything I might have missed. I don't know the history of these units but they're on a 1996 President MY. As a last resort I'm going to recover the refrigerant tomorrow, evacuate, and weigh in a new charge.
thanks in advance for your help...
Bill in JB

[Sailmonkey]

What are the vapor line and liquid line temperatures when you measure those pressures?

[Quadrille in JB]

Originally Posted by Sailmonkey

What are the vapor line and liquid line temperatures when you measure those pressures?

I didn’t check the temperatures on the unit that is cooling well but goes off on over temp But the unit that is not cooling well Had a suction line temperature of 84° F.
Think was so far off that I didn’t continue to check superheat on this cap tube system.
Thanks for your reply

[Quadrille in JB]

I suspect with the correct suction pressure and high discharge pressure and 84 deg. suction temp that the system is contaminated with non-condensables.
Any thoughts on this?
thanks,
Bill in JB

[Sailmonkey]

Both units sound like the charge is questionable, the water hot, and possibly the cap tubes slightly clogged.

Are these split systems?

[Quadrille in JB]

No they are not split systems
I agree on the possibility of contaminated refrigerant

[Sailmonkey]

I personally would check the charge with high and low side temperatures.

I use an iOS app called checkcharge to forgo the pressure temperature charts. I also enter the water temp as the condenser dry bulb temp and use a digital wet bulb thermometer inside to figure out how out of wack things really are. The high pressure isn’t too far out of the ballpark if the water is really hot as well.

[Quadrille in JB]

Originally Posted by Sailmonkey

I personally would check the charge with high and low side temperatures.

I use an iOS app called checkcharge to forgo the pressure temperature charts. I also enter the water temp as the condenser dry bulb temp and use a digital wet bulb thermometer inside to figure out how out of wack things really are. The high pressure isn’t too far out of the ballpark if the water is really hot as well.

I’ll try it
Thanks