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View Full Version : Airdale with blockage?



n1redrum
10-06-2008, 07:39 PM
hey, im currently working on an airdale heat pump, it is an all in 1 unit that sits on the roof and is ducted, it has 2 compressors which both have been changed and run on r22. the problem is when comp 1 runs the suction goes to 70psi and discharge pressure to about 170psi and the evap starts to ice up nicely. then after 2 minutes of running,if that, the low side starts to pull a vac and the evap melts. then the high side pressure starts to come down slowly to about 80 psi and discharge pipe gets a little cooler.

At first i though blockage in the system caused by moisture, but wouldnt the discharge pressure go up instead of going down in this case,or am i getting my wires crossed? maybe valves in the comp? any help would be appreciated, thankyou.

chemi-cool
10-06-2008, 08:10 PM
Are there two TXV's or Captube?

What doe's the second compressor do?

More details...........

n1redrum
10-06-2008, 08:16 PM
there are 2 txv's,its 2 seperate refrigeration circuits in one unit. nothing wrong with second system it runs like a dream. I would run it on that one compressor but i dont want to over work it.

chemi-cool
10-06-2008, 09:15 PM
In that case it will be easier for you to see the differences.

Look for places with different pipe temperature between the two circuits.

I believe this way you will find the problem.

I take it that there is no refrigerant shortage in the faulty circuit.

n1redrum
10-06-2008, 09:34 PM
no, gas was measured in correctly. both systems run at same pressures but after 2 minutes the 1 system goes in to a vac on the suction and the discharge also lowers. its this thats confusing me. when this happens you can see the evap completely defrost all the way back to the TEV but the second circuit remains fine (good pressures,evap iced)

Brian_UK
10-06-2008, 10:55 PM
Sounds like a blocked strainer or orifice in the TEV.

Jase
12-06-2008, 10:30 PM
Pretty sure these units use sporlan TEV's. If so then the power element on the valve has packed in.
Replace TEV and drier.

Jase

sedgy
30-04-2010, 03:46 PM
hi mi, have you tried running it on heating , just to see if it works on that mode ?