beer fridge buggin me
ok guys throw some ideas at me. and if it's too long just skip to the end for a good chuckle.
typical beer fridge behind the bar, aea4460yxa and 134a label on condensing unit.
I show up unit running...sight glass less than half full and check evap...ice on txv and on txv outlet pipe to evap coil...no ice on coil...turn off unit.
melt ice on pipe and leak check...leak on low side of txv flare nut...couldn't crack it tighter and needed two 15" adjustables to uncrack that puppy so I don't slice my knuckles.... SOMEONE has tightened this before it seems!
Pump down and replace nut...then test it again...no bubbles..good!
charge to sight glass and let it run 10 min. as I clean up
then I feel liquid line...seems too warm and compressor seems too cool and heavy frost on suction service valve and small patch on the compressor( this isn't a LT suprmrkt rack).... ok here's some numbers
suction 18 psig and several probe readings at compressor lowest was 22*F not much SH!(@4:30 too lazy to kneel on floor &fumble over beer bottles to get probe on evap outlet! it's only 24"away anyway)
discharge 150 psi...I was expecting 110-115psig.... LL temp 105*F...that's the warm to the touch signal that got me started on this.
ambient is 70*f......condenser has some dust bunnies but I've seen worse.
Around 40*F box temp more bubbles in sight glass
Head pressure seems too high and low SH.
So ideas... TXV stuck wide open...cause high head though???...maybe TXV stuck open and overcharged??? I really doubt I overcharged it, I was throttling vapour
non condensables....I shut unit down open doors to get evap to ambient and went back at 6:30...unit is off...low side 65psi..high side 72psi..ambient 70*F....doesn' seem too far off.
restriction?....no temp chnage at filter drier and besides low SH doesn't fit.
THE BEST PART IS THE OWNER WAS OVER MY SHOULDER THE WHOLE TIME AND WAS PLEASED WITH THE LEAK REPAIR BUT WHEN I MENTIONED THAT IT'S RUNNING OFF NORM I GOT THE QUIET GUILTY LOOK AND I THOUGHT "OH! NO! YOU'VE BEEN PLAYING WITH IT AND NOW YOU'RE TOO EMBARASSED TO ADMIT IT AND NOW YOU WANT ME TO PLAY SHERLOCK HOLMES WITH YOUR SYSTEM BUT NOT DISCOVER THAT SOME CURIOUS GEORGE HAS BEEN POKIN AROUND
... TXV stuck wide open...
Seems like as good a place to start as any. Pinch it down a few turns, see what happens.
The views and opinions posted here are my own. They do not reflect the corporate policies of my employer and will most likely get me fired at some point.
it sound's like the system has moisture in it was a new filter put in to system & NEW GAS?
a good way to check the txv is to get the box down to temp and then stick the bulb in warm water. you should easily see your suction pressure raise 10 psig. if it doesnt you probably have a bad power head.
hope this helps.
thanks for the replies,
I did add some new gas to get the charge up, no new filter/drier
but I haven't got a chance to look at system again...walk-in cooler down
Are evap fans running right? Correct rotation? Right blades?
actually I should look in to evap fans the owner said he noticed some blades were flat so he bent the blades to get a little more pitch thus airflow, but there might be more to that story. I did notice that the fan is not blowing down it's blowing up and out both sides of the coil...I couldn't remember which is proper...