- Joined
- Jun 15, 2003
- Location
- Cedar Rapids, Iowa
Well I've done a triple-evac on my system as recommended, charged the system to 60 psi low and high, started it, added more and more propane, temps dropping each time, then once I couldn't see the temp anymore (went below -50C on my crappy thermometer) I figured it was good enough.
The problem is that once it is on LLL (<-50C) for about 15 minutes, the temperatures very slowly start raising. In 20 minutes the thermometer is just getting back into it's range (-45 to -49), then in 30 minutes the temp is more like -35 to -40, then in 40 minutes the temp is more like -25 to -30, etc.
Right now the system has been running for about 45 to 50 minutes and the temp is @ -21.3, and very slowly raising. I mean like every 10 - 15 seconds or so it raises .1 - .3C.
Compressor isn't too hot -- probably ~ 100-110F (it's warm to the touch, but not hot).
Suction line is cold, but there's no frost very close to the compressor so it's not sucking back the refrigerant.
I have a huge condensor/fan so that's not the problem.
High side pressure is ~ 150 PSI. However, the schader valve for the high side is before the condensor, not sure if that makes any difference.
Low side is somewhere in the negative, not sure b/c my guages don't like negatives too much (they don't seem accurate).
Possible things that could be wrong in my head:
Ice in the system, blocking up the cap tube. I did a pretty good vacuum on the system. I let it vacuum for quite a while and then filled with a bit of propane on high side, suction on low side, then repeated a couple times. I also heated up my lines with a torch while in the vacuum to hopefully get rid of any moisture. My only fear is that my filter/drier my be saturated from when I stupidly put the system together. The only reason I think this might not be it is b/c the high side is still relatively moderate. Wouldn't the high side be much higher PSI if it was blocked? Right now it's @ 150...
Suction line/evaporator too restrictive. I think this might be in b/c the suction line isn't getting frosty except a little bit from the evap and there seems to be a pretty strong vacuum on the low side (though vacuum measurement was taken from the access port on the compressor, not the actual suction line). BTW, my flex hose is 1/4 inch inner diameter me thinks. 3/8 inch flare ends, but it's brazed on.
Okay, since the beginning of my post it's been like an hour (slow typer, I know), and the temp is now @ -12.5C and still very slowly raising, but a little faster than it was before.
So guys... What do I need to fix?
The problem is that once it is on LLL (<-50C) for about 15 minutes, the temperatures very slowly start raising. In 20 minutes the thermometer is just getting back into it's range (-45 to -49), then in 30 minutes the temp is more like -35 to -40, then in 40 minutes the temp is more like -25 to -30, etc.
Right now the system has been running for about 45 to 50 minutes and the temp is @ -21.3, and very slowly raising. I mean like every 10 - 15 seconds or so it raises .1 - .3C.
Compressor isn't too hot -- probably ~ 100-110F (it's warm to the touch, but not hot).
Suction line is cold, but there's no frost very close to the compressor so it's not sucking back the refrigerant.
I have a huge condensor/fan so that's not the problem.
High side pressure is ~ 150 PSI. However, the schader valve for the high side is before the condensor, not sure if that makes any difference.
Low side is somewhere in the negative, not sure b/c my guages don't like negatives too much (they don't seem accurate).
Possible things that could be wrong in my head:
Ice in the system, blocking up the cap tube. I did a pretty good vacuum on the system. I let it vacuum for quite a while and then filled with a bit of propane on high side, suction on low side, then repeated a couple times. I also heated up my lines with a torch while in the vacuum to hopefully get rid of any moisture. My only fear is that my filter/drier my be saturated from when I stupidly put the system together. The only reason I think this might not be it is b/c the high side is still relatively moderate. Wouldn't the high side be much higher PSI if it was blocked? Right now it's @ 150...
Suction line/evaporator too restrictive. I think this might be in b/c the suction line isn't getting frosty except a little bit from the evap and there seems to be a pretty strong vacuum on the low side (though vacuum measurement was taken from the access port on the compressor, not the actual suction line). BTW, my flex hose is 1/4 inch inner diameter me thinks. 3/8 inch flare ends, but it's brazed on.
Okay, since the beginning of my post it's been like an hour (slow typer, I know), and the temp is now @ -12.5C and still very slowly raising, but a little faster than it was before.
So guys... What do I need to fix?
