low suction pressure after compressor replacement.

[properdouble]

Hi Guys
I have replaced compressor today on a ZOIN multi deck fridge iot was aspera NJ9226GK.Cherged 1.1 kg R404a as on the cabinet sticker got it ryunning to find low suction pressure at about 30 psi means evaporating at -30. Almost like subcolled liquid in bottom of condenser.All airflows ok clean condenser with OFN after pressure test,cabinet working like i wish coming down hitting 2 degress setpoint with no time ambient around 17 degrees all working ok just low suction pressure it is a capillary tube system ,just wonder would it be ok i have left it like that as it was working fine just would expect higher pressure perhaps it is winter and servery was cooler than during operational hours.just a tought .what you think???
Best Regards.

[install monkey]

drier changed? how long did you vac it for, and what did your torr gauge show?
what did the last pot die of?

[properdouble]

Hi
Didnt change dried as run out of them and vaccumed for about 45 min it was showing 1 torr, i belive last pot died from chocked condenser as when i blew it with OFN it was foggy as hell in the servery i belive was overheeating,funny enough cabinet is flying down it took les than 10 min to hit setpoint cooled by 15 degrees.
Thanks for quick reply.
eventually after few cycles it would cut back in and start piuilling down form 80 psi standing whilst temp coming down pressure cradually coming down to about 30 and hanging there for a while till stat cut out.

[install monkey]

when its running chec for any temp diff accross drier - over 1 deg then its restrited- capillary line could be partially choked- after vaccing to 1 torr- was the torr gauge on ur vac pump or manifold? - ideally placed at the furthest point of the system- ie liq line, but not always possible- once vacced, shut gauges and moniter torr gauge(on system) to see if theres any backdrop- indicating moisture- any consilation 10yr ago i topped up a chest freezer on a petrol station- (no hp connection)- sat round drinking me coffee and filling out a sheet( this was before 2079)- BANG- drier blocked and splattered dessicant and 502 into the shop! haha

[fridgability]

The drier could be restricted with crap from the failed compressor or the capillary tube could be partly blocked. However that does not tie in with the good pull down. An acid test and new drier would not be out of place.

[Gary]

What was the superheat?... subcooling?

[properdouble]

It is not easy task with calculating superheat, subcolling on multi deck without hp gauge and direct acess to tev to be honest i never measure those values maybe i shoul start get in to habbot of doing that however aint got clue of how to do it efficiently the only time i do ot is on the course as i do vqr diploma in refrigeration air conditioning and heat pumps i have got so many questions and no answers havent heard anything so it must be running well just didnt sound right.

[G Cook]

I would try and get back and change the filter, not worth killing the new comp.

[nike123]

If I were there, I would change drier and capillary tube.

[Gary]

That type of system may have an evaporator pressure regulating valve (EPR aka SORIT valve) in the suction line. This maintains higher pressure in the evaporator, which helps keeps the humidity higher in the box... and lower pressure downstream.