What the heck is wrong???

[Jesus Quijano]

I installed a 10 HP scroll comp condensing unit for a walk in freezer as a replacement everythig is working beautifully at -10 degrees F the problem im having that i cant figure out is

the condensing unit in its off cycle will start and short cycle due to the pressure increasing very slowly as if the liquid line solenoid valve was leaking through which is not because i replaced it twice but

it seems to do it twice on every pump down cycle and not back to back but minutes apart and not even cose to cut in temperature release of liquid line solenoid valve
Anyone ever have this problem????

[taz24]

I installed a 10 HP scroll comp condensing unit for a walk in freezer as a replacement everythig is working beautifully at -10 degrees F the problem im having that i cant figure out is

the condensing unit in its off cycle will start and short cycle due to the pressure increasing very slowly as if the liquid line solenoid valve was leaking through which is not because i replaced it twice but

it seems to do it twice on every pump down cycle and not back to back but minutes apart and not even cose to cut in temperature release of liquid line solenoid valve
Anyone ever have this problem????

Hi

Two things come to mind

The first is what is the differential set to on the
pressure switch controling the comp.
If it is too narrow the comp will cut in once or twice
untill it clears all the refrigerant from the evap.

The other is the check valve in the comp could be
weaping and the high side pressure is bleeding back
to the low side.

Cheers taz

.

[Jesus Quijano]

thanks for your reply

the cut in-out are facory set at 1 and 25 psig for 404a seems right according to the tp chart

i have a scroll compressor and the only valve connected to is is the llsv and the liquid injection which one do you mean bleeding through?

[nike123]

http://hvac-talk.com/vbb/showthread.php?t=92050
http://www.refrigeration-engineer.com/forums/showthread.php?t=3083
http://www.apcmedia.com/salestools/TDOY-5UQVE6_R1_EN.pdf

[cadwaladr]

I installed a 10 HP scroll comp condensing unit for a walk in freezer as a replacement everythig is working beautifully at -10 degrees F the problem im having that i cant figure out is

the condensing unit in its off cycle will start and short cycle due to the pressure increasing very slowly as if the liquid line solenoid valve was leaking through which is not because i replaced it twice but

it seems to do it twice on every pump down cycle and not back to back but minutes apart and not even cose to cut in temperature release of liquid line solenoid valve
Anyone ever have this problem????is there a crankcase heater fitted have you got your guages on both suction and delivery? to double check.

[monkey spanners]

It could be the discharge check valve as already mentioned, it is inside the compressor.
If its a new compressor i suspect it will improve once it has run a few days.
There a lots of vids on youtube of cut open scrolls which show all the working parts which you might find interesting.

http://www.youtube.com/watch?v=74_DTDY2G5Q&feature=related

Jon

[marc5180]

Good video Jon, i've never seen a scroll cut open so thanks.

[coolhibby1875]

you really should fit a anti cycle timer this will help!