A/C cooling problem

martin

I own a duplex rental unit and am putting stand alone A/C in attic. I bought the equipment 4 years ago when companys were getting out of their R22 stuff. equipment is Goodman 1.5 T cap. I do install professionally but this is someting I've never seen. When I started up the condensing unit my low side went to 5psi, high side 150. I added some extra 22 the lines were 15' longer than factory charge,but it didn't change a thing. So I shut the unit down and it would not equalize. Anybody have an idea what the problem might be.

Empire_2

Equalize?

Wre you using TXV or restrictor fixed orifice?  Sounds like you may have a restriction causing a pump down effect.  Was the equipment sealed before install? is everything new? 



Mike T.

martin

cooling problem

Everything is new ,fixed orifice system. Recovered refrigerant and checked orifice,clean. Shut service valves and pulled valve cores on condenser and blew nitrogen in liquid side, no obstructions in air handler or line set. Took temps today when checking 154 coming out of compressor, 82 coming out of condenser coils on both sides of filter dryer, @175 psi . Today when I ran the unit my low side was 45 and high side 175. On sunday I changed out the complete condenser unit because I had 2 this on started at 25 low side and 175 high side. Talked to 2 wholesalers they're baffled.

Techman

problem

Can you determine if you have a full liquid line at the metering device?Add a sight glass/moisture indicator just before the air handler or if you're good enough you can  hold the liquid line and "feel" for activity or get an ultra sonic "sight glass" .The system might be low on freon.What is the superheat @the comp?

Empire_2

Need more info

When you come back, We need everything.  Out door temp, wet bulb inside, measure sub cooling and super heat.  Check after 5 min of operation, then 10 and so on.  In your original post you stated that it would not equalize?  That is a clear blockage most likely at the evap.  Sub cool measurement will at least give you an idea of whether you are under charged or not.  Just as a quick refference, Add 30 to your out door ambiant and your head should be somewhere in  that area.  Do this so I can get an idea of what you are dealing with.



Mike T.

Techman

OH!

Would not equalize? Skipped right over that sentence! Thanks Mike T.But w/ the 2nd cond unit,it might be low on freon.

Empire_2

Yea Terry, Possible under charge.

Like most question on this topic, not enough information is given to diagnose anything.  Details, details, details.  Before changing the condensing unit out, problem should have been addressed.  I hope the system had an evacuation proceedure before charging.



Mike T.