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View Full Version : 404 flashing b4 TXV


1coolguy
08-10-2009, 04:39 AM
cornellius xrc1444 machine, machine has run fine for three years, low production lately, quick inspection found pressure switch at condenser was bad, (would not close swith on pressure rise and stay out), replaced, ran fine for two weeks and now customer states low production, checked condenser fan and running fine, line set very hot and no "heat" pulling through condenser. i am thinking the 404 is flashing before txv, but why and why no heat off condenser?????
thanks in advance
lowcool
08-10-2009, 04:59 AM
sounds to me like your compressor is inefficient/damaged reeds.
nike123
08-10-2009, 07:48 AM
Check subcooling before TXV. If you dont have 2K or more than it is possibly flashing (2K is minimum required subcooling if you don't have liquid receiver).
Check proper fan rotation direction and RPM. Check and clean condenser.

We also need more data to be able to help you in meaningful way.

http://www.refrigeration-engineer.com/forums/showpost.php?p=151612&postcount=5



http://farm4.static.flickr.com/3213/2900913505_64df73c316_o_d.jpg
1coolguy
09-10-2009, 05:10 PM
i have no temp diff across txv's and the pressures at remote cond are 175/175. the pressures at machine are 40/180. when the machine starts freeze cycle, the pressures are 60 and 260, after 5 minutes the flashing begins ( i am assuming this is what is happening) and pressures are back to the 40/180. Could the vales be going out in this hrermetic??? would it run for a few mins and then go wacko??
nike123
09-10-2009, 05:24 PM
i have no temp diff across txv's and the pressures at remote cond are 175/175. the pressures at machine are 40/180. when the machine starts freeze cycle, the pressures are 60 and 260, after 5 minutes the flashing begins ( i am assuming this is what is happening) and pressures are back to the 40/180. Could the vales be going out in this hrermetic??? would it run for a few mins and then go wacko??

Check temperature difference at inlet and outlet of Filter-Dryer and change it if difference is more than 0,5K (1°F).
What about other data like subcooling etc...
1coolguy
09-10-2009, 06:36 PM
no temp diff at drier, subcool is 60*.
1coolguy
09-10-2009, 06:41 PM
btw.. nike123, i do have a receiver, if that helps
1coolguy
09-10-2009, 08:00 PM
more info.....
pressures-15/125
before txv temp. 96*
after txv 77*
77*entrering plates, 57*out.
suction temp at comp. 73*
subcool is 30*, temps are raising longer machine runs. acts like it is low on charge, already 6oz. over weigh in charge.