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TECH TIM
11-03-2009, 12:21 PM
hi all,
just wanna ask some opinions if poss, as some of you may know im new to commercial, i changed a small condensor unit today, it was a heatcraft kirby ba9 unit, i changed the dryer as well and was advised by our supplier to remove liquid reciever as it is a capillary system, i tripple evaced system and charged r22 (original used) i started up and system was slightly short soi added some more, i finished up with suct 47psi, -5°c sst, and 9°c on suct line exit cabinet (cabinet was not down to temp was at 12°c) that was 14k super heat, liq line worried me though it was up 380psi, 67°c sct, but the liquidline temp was perfect at 34°c, the system is approx 5 ft wide and has a coil built in storage area floor, it also has a static coil at top which is a horizontal 3 turn evap, no s/air or r/air readings avail but unit took 15 mins (once pressures wer ok) to cool from 27°c to 15°c and dropped fast, air on cond was 29°c air off was 39°c, after a while longer i began to get some flood back so i recoverd a small amount taking frost bak to around 25 cms from evap exit, my new suct pressure was 41 psi, -8°c sst, and still about 9°c on suct line, liquid line was still high at 335 psi, 60°c sct, and still about 34°c on liquid line, is it normal for a capillary controlled unit to have a higher liquid line pressure?? sorry for beating around the bush and sorry if i just confused yas with my dribble but any q's or input will be appreciated take it easy guys. oh, by the time i left it was 6°c and no more flood backs im confident its working ok but just not sure if liquid line pressure too high

Temprite
11-03-2009, 02:09 PM
the system is approx 5 ft wide and has a coil built in storage area floor, it also has a static coil at top

Neither coil has fans?

Coils without fans will run lower suction pressure sounds like it is over charged and thats why you have the high side pressure you have.

Let is get close to temp and check then.:)

Brian_UK
11-03-2009, 08:23 PM
As Temprite says, check at design cabinet temperature.

You action of 'adding a bit more' before the case temperature had stabilised at design gave you additional problems.

kiwifridgie
08-05-2009, 11:35 AM
aim for a minus 20c sst at temp when charging a static coil. whatever the gas. some slight adjustment may be required but you'll be pretty close.

cadwaladr
08-05-2009, 08:26 PM
was the condensor the same size as the original and what was the reason for replacement

Yuri B.
09-05-2009, 05:36 PM
I hope that Tech Tim himself, at least, stays safe and sound after the repair. I wish we were more often providing follow-ups on our problems, no matter what the issue was.