Bad valves in a compressor? R-22

Question

I read here an answer to a question about bad valves and was picked best answer. The person claimed that he has seen bad valves with 95 psig pressure suction gave him a 18 degree TD? TP chart at 95 psig is 56 degrees, I would love to hear the explaintion to this one? Question what causes noise in the liquid line at the Air Handler? Why trap drain lines? When run capacitors keep blowing and NO line volt problem, first place to look, new contactor installed?

Answer 1

When a compressor has bad valves ,the tp chart is not always applicable and will leave you scratching your head trying to make sense of it all.95 lbs doesnt always mean a 56 degree evap when bad valves are encoutered.Check the temp at your coil and don't rely on just a tp chart.You do this long enough, and you will run across it sooner or later.

Noise in the liquid line would likely be caused by a tubing rattle or a too great of a pressure drop across the valve.(too high head)

Drain lines are trapped to eliminate negative pressure in the drain to allow for proper drainage.

Run caps blow most often when the wrong size is used or wrong voltage rating.

Answer 2

On thing at a time...Bad valves. OK, high suction pressure, low head pressure. When condenser is disconnected, the pressures equalize very rapidly, and you can hear this happening. The pressures you see on the Gage reflect the severity of the leakage of the bad valve.

Next, you only have to trap a drain if you are on the suction side of the fan. If you are on the positive side, it naturally runs to the drain.

Noise at the air handler liquid line could be improper installment of the accurator (metering device).

Is the capacitor for the compressor, or the fan?

If compressor, I would suspect high starting torque. Install a start kit with a start relay, and this will go away.