Replymake sure that the diagnostic really is: Low Pressure Cutout - Ckt 1
if the diagnostic is different, then it could be something else otherwise monitor the low pressure switch (voltage side) while watching your gages to find out for sure.
Regular Guest
Package chiller tripping on low pressure latch fault. actual suction while monitoring is 60Psig and display is reading about the same. Discharge pressure running around 225-250.
2nd stage runs like a champ after stage 1 trips out, so ive ruled out a flow issue...water temp running at 47 degrees. flow switch is working as it should....At this point im looking for ideas whether u think its the pressure switch near the barrel going bad or if exv is closing/not opening as it should.
Professional Member
make sure that the diagnostic really is: Low Pressure Cutout - Ckt 1
if the diagnostic is different, then it could be something else otherwise monitor the low pressure switch (voltage side) while watching your gages to find out for sure.
"Right" is not the same as "Wise".
Don't step on my favorite part of the Constitution just to point out your favorite part.
Just because you can measure it, doesn't mean it is important. Just because you can't measure it, doesn't mean it isn't important.
Professional Member*
X2Originally Posted by jayguy
Post the exact alarm the chillers calling out. There are other similar alarms that mean different things.
Regular Guest
Monitored unit today and was tripped on low pressure again... checked pressures and was running 60 and 230 at 50 degree water temp. Superheat was 6 degrees and subcooling was 20. Going to change pressure switch near the barrell and gk from there unless you guys have any other input?
Professional Member*
Your not going to post the exact alarm?
Professional Member
you WATCHED it trip with those pressures or...it tripped....and then later, after you reset it, you had those pressures?
"Right" is not the same as "Wise".
Don't step on my favorite part of the Constitution just to point out your favorite part.
Just because you can measure it, doesn't mean it is important. Just because you can't measure it, doesn't mean it isn't important.
Professional Member
We use to get that alot on those chillers, just replace the switch. If you take it off and test it, it is probably opening higher than it should.
Regular Guest
r123 the alarm was low pressure cutout...it was a latch fault alarm.
jayguy i reset the chiller and minutes later it alarmed again...then i reset it hooked up my gauges, put comp. 1 in test mode, thats when i checked pressures, superheat, and subcooling. The compressor did not trip after that.
Regular Guest
RTAA does not have a transducer. It shuts down on low pressure if the low pressure switch is tripped. If it is tripping on low pressure but you feel that pressure is adequate then I would suggest investigating/replacing low pressure switch. When you were measuring the pressures what percentage was the unit running at? It needs to be near fully loaded.
Regular Guest
looks like it you have bad switch,switch open up at 7lbs ±4(this is from the rtaa IOM) if you need a copy let me know.
Compressor Discharge High Pressure
Switch – PSIG
300 ±20 405 ±7
Compressor Motor Winding
Thermostat – F
181 221
Low Pressure Cutout 22 ±4 7 ±4
Regular Guest
btw: The pressures displayed on the screen are calculated pressures based on temperature and various other items on the RTAA.
Professional Member
Run the EXV test as well. Make sure it passes that.
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