Air Conditioning Malfunction

[The Mons]

Hello:

My Cruiseair SX16 with SMX control is not cooling properly. The compresser sounds like it is running. However, when I put on a set of gauges, it the suction and discharge sides showed the same pressures. This is different from other times that I have hooked up the gauge set and have had suction and discharge readings.

Does this mean my compresser gasket or switching valve for the reverse heat is toast?

Any other ideas?

Thanks.

[AnchorageGuy]

This means that if you are not sure about troubleshooting the system you need to have an AC service outfit look at it for you and make the determination as to what your problem is. It may very well have lost the charge which means a leak somewhere or it might be some other issue.

[Palarran]

Most likely your compressor isn't actually running. Use an amp meter and check. If you put a set of gauges on and the pressures don't change when you turn the unit on, either the compressor isn't running or the valves have gone bad. Is the top of the compressor hot?

[The Mons]

Rigamarole:

Thanks for the input.

The ampmeter says 14.5 amps which I think is close to the normal current.

The top of the compressor gets warm, it is vibrating.

One other thing that I observed is that you used to be able to hear the pressure equalize after the unit was turned off. Now you don't.

There are no error messages of any kind on the digital display.

[Palarran]

Are you using quick connect hoses? You said both discharge and suction pressure are the same with the unit running - what is that pressure? Does it change when you connect the gauges? Also, what refrigerant are you using?
There are two tubes that come out of the compressor. The small one is the discharge line which should be hot - like it can burn your fingers if you touch it. The bigger one should be cold. Is there any change in temp when the unit is running?

[The Mons]

Rigamarole:

The hoses are the regular twist on type. I purged the hoses from the can. The pressure on both sides is 150 PSI after they are tight. It has R-22. The pressure on neither gauge changes when the unit is running with the compressor vibrating.

Also, I didn't specifically notice any change in the temperature of the lines exiting the compressor.

[Palarran]

Well, the amp draw doesn't make sense as 14 amps should be doing some work. Did you take the reading on one of the wires going directly into the compressor or the power wire going into the unit?
My guess is your in locked rotor, where the compressor is energized but the motor won't spin. If you go to a refrigeration supply house or air conditioning repair company you can buy a compressor capacitor booster. It just connects up to your existing capacitor and gives the unit a extra boost of power when starting. Full directions are on the package. If you put one on and the compressor still doesn't start, I'd say its shot.
You can test the winding on the compressor if you want by first disconnecting all power to the a/c, remove the three wires that go the the compressor and using your ohm meter to check the windings of the motor. You should see one letter markings on the compressor R,S,C or Run, Start, and Common. Using your ohm meter, check the resistance between all three and the equasion should work RC + SC = RS

[The Mons]

Rigamarole:

Not too much in this does make sense. The amp reading was taken from my AC panel with only the airconditioning on.

It did this once before 7 years ago and then miracilously fixed itself without intervention. I believe the unit to be at least 11 years old. I may have to resort to a new unit.

Thanks for the help.

[Therapy]

Originally Posted by The Mons

It did this once before 7 years ago and then miracilously fixed itself
.

Time for a good WHACK. One before you energize it and one after. Let us know.

[Palarran]

Good suggestion Therapy, I usually do that right before replacing a unit!! 3 foot 2x4 works best.

[Artful Dodger]

does the compressor have power and ground to it, and if there is no cycling of pessures and they are constant, 150 is not what it should be. If a system is to equalize you would expect to see around 50 psi on each gauge. What type of connections are there, are they both different which would not permit a wrong connection. There are some basics without running the system, make sure you have the correct power and ground, also test the clutch engagment by testing it with alternate source. Sometimes too by just unplugging a system and restarting they correct theyselves.