water cooler questions

[John_GR]

Hello to everybody.This is my first thread to the forum and unfortunately i will haveto post about a problem i have with a water cooler.First of all let me say that i am working as a refrigeration tech for about 7 years and my employment sector is mostly domestic a/c units(split type).I've also had some experience with ice making machines.Here is the problem: recently a friend of mine who owns a cafe asked me to repair his water cooler.The cooler is quite old and the problem presented was electrical shortcircuit.At my first visit i connected the power suply directly to the motor and the power went down.I figured that the problem was shorted motor.I purchased a new motor and replaced the old one and also replaced the filter.Piece of cake!But it was then that my problem begun..Having little to none experience with r134a i didn't know at what pressure it works.The manufacturer suggested 250 grams.I vacumed it and filled with 250 grams.When it started working the low side would show below zero pressure.I thought there was a blockage so i had to reopen the circuit and press it with nitrogen.Everything seemed ok,i put a new filter and did the same again.With 250 it would still work below zero pressure.Only when i filled about double(500 grams) i saw about 10 psi on the gauge but the low side of the motor was then white with ice!!The water would not go below 8-9 degrees(about 45 f)and the motor sounded weird.Unfortunatelly i can't take messurements from the high side.From here on i'm in the dark..Any suggestions from someone more experienced would save me!I have a couple of pics of the cooler that i will post later.

[mikeref]

Did you fit the same size drier or larger capacity? Is the drier feeding up hill or anyway different from original design?
Is the compressor an exact match for the one you removed.

[John_GR]

Did you fit the same size drier or larger capacity? Is the drier feeding up hill or anyway different from original design?
Is the compressor an exact match for the one you removed.

i fitted the same size drier(30 grams.)the drier is in hrizontal position,exactly like the one i removed.The compressor was given to me at a local store as simmilar to the one i was going to change.

[John_GR]

some pics i took last night

20140907_205229.jpg20140907_204919.jpg20140907_204945.jpg20140907_204929.jpg20140907_205237.jpg

[mikeref]

Trouble with capillary tube. In picture #2, 500 G is raising head pressure and forcing refrigerant through a restricting capillary tube. Run your hand up the side of the condenser. There will be a distinct point where warm refrigerant turns cool.
That's where the liquid level is at, backed up in the condenser.

[John_GR]

Trouble with capillary tube. In picture #2, 500 G is raising head pressure and forcing refrigerant through a restricting capillary tube. Run your hand up the side of the condenser. There will be a distinct point where warm refrigerant turns cool.
That's where the liquid level is at, backed up in the condenser.

that's correct.any sugestions for my next move?should i change the capillary tube?

[mikeref]

Reclaim your gas and replace cap tube. Was this cooler originally on R134a?

[John_GR]

Reclaim your gas and replace cap tube. Was this cooler originally on R134a?

yes it was r134a.what do you mean cap tube?

[mikeref]

Cap tube is the Capillary tube. My bad for not writing correct English. Your picture # 2 shows the tubing after the drier.
That capillary tube is likely to have a restriction...beyond manufactures specifications.
In other words, adding more refrigerant increases the high side pressure and forces liquid refrigerant through the Capillary tube restriction.

Your over-charged system is holding liquid in the condenser where normally a liquid / vapour mix leaves the condenser and runs through the copper drier and enters the Capillary tube.

[frank]

R134a + Capillary = BLOCKAGE. (oil flocked)

[John_GR]

thank's for the answers so far guys.my bad for not understanding cap tube.The thing is that i thought i had the capillary tube cleaned.I'm saying that because i pressed the low side with nitrogen and everything seemed ok.This ,now leads me to believe that i might have a leakage inside the evaporator.i'll try a few things and i will let you know.Thanks for the help!!

[AmeliaBrose]

R134a + Capillary = BLOCKAGE. (oil flocked)

great caught ..