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bwd111
28-02-2014, 09:50 PM
Working on a subzero res refrigerator and getting 240 psi highside and -(neg) 3.5 to 0 psi on suctionside. When using vaccum pump heard a loud thump from compresser never heard that before also switched out filter drier as I couldnt get system to equilze with nitrogen thinking there might be a restiction , main concern is why on this r-12 unit would I see these pressure after charging. I never seen 0 psi with highside as high as psi was. Also can get comp over 2.6 amps when correct amps is 7.0 amps

mikeref
01-03-2014, 08:59 AM
What is a "RES" refrigerator. :confused:

passandscore
02-03-2014, 01:46 AM
Does it have a capillary line metering device? If so, then it sounds to me that it is obstructed. That would account for the pressures that you're seeing. Does the unit have a low pressure control?

Check this out
http://www.supco.com/images/pdfs/Manuals-Instructions/Cap%20Tubing%20Manual.pdf

bwd111
04-03-2014, 04:18 PM
What is a "RES" refrigerator. :confused: RES ( residential)

bwd111
04-03-2014, 04:25 PM
[QUOTE=passandscore;293033]Does it have a capillary line metering device? If so, then it sounds to me that it is obstructed. That would account for the pressures that you're seeing. Does the unit have a low pressure control?

Check this out
http://www.supco.com/images/pdfs/Manuals-Instructions/Cap%20Tubing%20Manual.pdf[/QU

Yes it does have a captube and am thinking restriction but when I blow nigtron through I get pressures coming back on both low and highside. If I close the ball valve on my sharder puller valve on lowside then open after I push nitrogen through highside of 144 psi I get the full 144 psi coming back but if I dont close valve I get 144 on highside and 15 psi on lowside and NO low prseeure switch. First pressure I saw before replace filter drier were as follows 4.4 psi (83.4 SH) and 108.1 highside (20.7SC) Then after vaccum and new filter drier had 0 psi to neg 3.3 ps1 and 240 highside psi. But I am going to replace captube

mikeref
05-03-2014, 07:26 AM
It's easier to push Nitrogen through a capillary tube as opposed to liquid/vapour refrigerant mix. That means a higher head pressure under balanced working conditions.
Is your new drier the same capacity? 240 PSI is too high and you'll find the drier is dead cold when appliance is running. Good luck with your cap tube exchange as some are a pain to replace.