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18 days ago guys. Old news.
Originally Posted by daygotech check the superheat on all txv checked all cases for no floodback due to clogged drain bad defrost heaters etc next check to make sure the superheat is set correctly on compressors copeland recommend 13 degrees at compressor thats way low for a rack system at the suction service valve brother need to pull out the AE book and get the proper superheat at the compressor but the starting point is the evap and then the compressor and if its line then all is good if not piping is a problem
Originally Posted by daygotech check the superheat on all txv checked all cases for no floodback due to clogged drain bad defrost heaters etc next check to make sure the superheat is set correctly on compressors copeland recommend 13 degrees at compressor Has it changed??? I thought it was always no less than +20F and no more than +40F at the compressor.
check the superheat on all txv checked all cases for no floodback due to clogged drain bad defrost heaters etc next check to make sure the superheat is set correctly on compressors copeland recommend 13 degrees at compressor
Originally Posted by fuzzyj A tripped oil safety switch doesn't necessarily indicate a flood back problem. A single phase condition, caused by either a power failure, or burned contacts on the compressor contactors could also cause your oss to trip. I suspect this was a gradual condition, ocuring over several days. if the system is computer driven, you may be able to access the history logs to help you determine what happened. remember, no good deed goes unpunished Good point. I took it as a given the oil trips were in fact due to liquid floodback. Can't assume anything really, can we?
A tripped oil safety switch doesn't necessarily indicate a flood back problem. A single phase condition, caused by either a power failure, or burned contacts on the compressor contactors could also cause your oss to trip. I suspect this was a gradual condition, ocuring over several days. if the system is computer driven, you may be able to access the history logs to help you determine what happened. remember, no good deed goes unpunished
I had a rack about 8-9 years ago wash out the oil starting on a weekend duty weekend. Hussmann Super Plus Would go to the store , pump out every thing , spend 2-3 hours and could find nothing. This happened 3 times in one wekend. Eventually found the heat reclaim 3-way valve pumpout line had been replaced with the 3-way valve 2 months before and had not needed heat pretty much since the install. That weekend , the weather was changing so the heat was cycling. When we'd show up the store was calling for heat so everything was fine. The suction lines were fine at the header and any circuit close to cold we'd dig into the valves , but never really found anything. When heat satisfied,the pumpout would flood like a sum*****. The guy that did the 3-way valve upsized the pumpout from 1/4 to 3/8. He was the only guy that knew this. I think we cut in a section of 1/8" tubing to meter the pumpout. Problem solved That was a curve ball...
Originally Posted by jaybee well it might meduim temp system,iced up compressors common suction, 4 of five compressors are off on ofc and there is refrigerent visible in sightglass at the crankcase call has came back 2 times ,again just a guess didnt measure superheat at the comp. If your rack flooding out as bad as it sounds like it is............this shouldn't be too terribly hard to pinpoint. My first guess would be a check valve failed (assuming gas defrost) or a heat exchanger cracked internally. A fully open TXV will cause problems on a single compressor system but on a rack with a suction accumulator I haven't seen a single TXV wipe out a compressor yet...........not saying that it CAN'T happen.........just sayin'
Originally Posted by crackertech what's wrong with that plenty of sub cooling. Okay crackertech, you gotta add a "n" to your signature that ends in moring. I can't sleep at night thinking about it.
Originally Posted by powell Brrrrr!!!!!!!!!!!! No Demand cooling trips here
Originally Posted by powell Buurr!!!!!!!!!!!! what's wrong with that plenty of sub cooling.
Originally Posted by Dowadudda ice, or frost automatically doesn't mean flooding. Brrrrr!!!!!!!!!!!!
jaybee is this a loop system ? ie commom suction and a common liq feeding many cases. or is a single system feed?
Originally Posted by Dowadudda ice, or frost automatically doesn't mean flooding. dow this is true its just another tool I use to start.
well it might meduim temp system,iced up compressors common suction, 4 of five compressors are off on ofc and there is refrigerent visible in sightglass at the crankcase call has came back 2 times ,again just a guess didnt measure superheat at the comp.
ice, or frost automatically doesn't mean flooding.
Well didnot go back . An jorneyman did and when I ask did he find the floodback he had no answer. As far as i know it came in again and all the person did was get the rack going . Well, if i have to go back i got good info to go back with . So the 411 is it's an unresolved issue, but then again im just a dumb appr.
Originally Posted by chilly123 Hey jaybee whats the 411 on this? Yes what's up.
Rack flooding Hey jaybee whats the 411 on this?
Rack flooding
Originally Posted by CommtechinVA ECI is famous for refer temp sensors failing. case controllers set up to maintain a specific temp difference from refer inlet to refer outlet. EEV's wide open and cases flooding. I've spent many days just going thru stores, changing sensors. I've seen compressor discharge lines frosting and heads iced up and compressors still running. Can't remember why we didn't trip oil safeties. AAH, Gotta love refrigeration!!! Bill Amen to that
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