bottle fridge not cooling

[lorano]

Hi guy's
Was working on a bottle fridge today,was sent to fit a filter dryer and capilary tube as the previous engineer reckoned the capilary or drier were blocked.fitted the new parts no hassle,pressure tested,va'cd out and weighed in the gas charge(r134a 150grams).The problem i have now is it still wont cool and the compressor is pumping itself into a vac so there must be another bloackage somewhere right?The evporator coil is still recieving refrigerant as it is getting cold and the fridge temp was dropping to 14 degrees c but no lower.Surely my new parts cant be blocked?I was super careful when brazing the capilary line in as i know how easy it is to block them.Any ideas?I'm going to have to return tomorrow and remove all the brazed connections and blow them through with ofn.The evap coil on these sits half way up the back of the fridge and i did notice when i removed the old capilary there was a lot of oil coming out from the top pf the coil,could there be oil in the evap coil causing the blockage?

[install monkey]

moisture? - degas it, move the fridge to a warm area - are u vaccing through a line tap valve? fit a 1/4 schraeder stubb- maybe fit a drier with a chargin stubb too, capillary lines can wax up if pot on its way out, blast the cond coil with nitrogen, as the face of the coil can be clean but inside can be furred up

[lorano]

moisture? - degas it, move the fridge to a warm area - are u vaccing through a line tap valve? fit a 1/4 schraeder stubb- maybe fit a drier with a chargin stubb too, capillary lines can wax up if pot on its way out, blast the cond coil with nitrogen, as the face of the coil can be clean but inside can be furred up

It had a line tap on it which im not a fan of so i removed it and fitted a shrader valve,blasted the condenser coil as well.I was vacing it inside the building where it was abmbient temp.I'll just have to undo what i did today and blow everything out?!

[install monkey]

when cutting the capillary tube use snips and score round the end and use long nose pliers to wiggle the end till it snaps and make sure you dont insert the capillary too far into the drier

[mikeref]

Capillary tube the correct length and same inside diameter as the original?

[lorano]

Capillary tube the correct length and same inside diameter as the original?

It was the same diameter but maybe slightly longer in length,would a longer capilary make a difference,the system is pumping itself down until there is no suction pressure at all.

[The Viking]

Well that is sort of what the capillary tube does... It regulates the flow of the refrigerant, the longer the tube the higher the resistance the refrigerant has to overcome and the lower the flow will be. The more length you added the higher the pressure drop and maybe even enough to send the suction side in to a vacuum.

But before you start cutting things... You are sure there is enough charge in it and that it is liquid going to the capillary tube?

:cool:

.

[mikeref]

If your drier is a larger capacity and is horizontal or the outlet is facing uphill,then you will need more refrigerant. Critical charge systems, best to have outlet facing down hill.

[Magoo]

Tell the original service engineer to sort the problem out. seems you are only getting half the story. I seriously hate taking over other techs problems.

[lorano]

Tell the original service engineer to sort the problem out. seems you are only getting half the story. I seriously hate taking over other techs problems.

When i inspected the fridge the drier had been removed from the 1/4 pipe just after the condenser coil,the capilary line was still there coming from the evaporator coil.The drier was mounted horizontal.The evaporator coil must be a good meter high mounted on the back of the fridge but this mustve worked from the factory.The old capilary line was coiled round the 3/8 suction line in pretty tight coils,i guess to keep it 'safe'.When i installed the new line i didnt wind it as tighly round the suction line as i didnt see the need,i did end up with a bit extra before connecting to the drier but just wound it up,wasnt much to be honest,didnt want to cut the line as it had a perfect hole in the end of it.

[1mikeefc1]

Only going off my experience but data plates I find are often wrong, I tend to go off pressure and temperature, around 1/1.5 suct with a cold sweat back to the compressor, if its freezing to the comp it's over charged(assuming the evap fans are working)

[lorano]

The charge on the plate stated 150 grams,which is nothing.It was cooling but only down to 14 degrees C,the evap coil was frosting over but like ive said its pumping into a vac.Rip apart and start again i think?!

[1mikeefc1]

Is the coil frosting over completely or partially? Also what does the suction line feel like, if its not getting a cold sweat I would be questioning the charge.

[Andy AC]

Do the pressures equalize fairly quickly when you switch it off, if they do I'd stick some more gas in to compensate for the drier and any other additional pipework you may have done.

[lorano]

Its only frosting partially from where the capilary enters and maybe 1/4 of the coil,the suction line doesnt feel cold which is why im thinking its not pumping back a lot of refrigerant?To be honest the whole thing is a nightmare to work on,i can pull all the workings out as its on a tray which means i have to remove the back plate which covers the evap coil and keeps the 'draft' in so when removing the back i get no air flow over the evap coil.i have to do this as the pipes are contained behind the back plate and the shrader is virtually impossible to access without pullin it all out

[Andy AC]

What make is it?

[1mikeefc1]

It definitely short pal if you wanna be certain stop the evap fans and let comp run if its charged correctly the whole coil will frost over.

[lorano]

It's an IMC TC60,i've only the shrader on the compressor plug to work with but yes when i switch it off it eqaulizes fairly quickly.

[The Viking]

If it's that hard to work on why not add more refrigerant and see what happens?

Must be the easiest thing to do...

:cool:

.

[lorano]

It definitely short pal if you wanna be certain stop the evap fans and let comp run if its charged correctly the whole coil will frost over.

Would a gas shortage cause it to pump into a vac on start up?

[lorano]

I'm thinking that now;)

[1mikeefc1]

Yes it would and if its equalising out quickly enough it proves no blockages. Good luck.

[lorano]

It definitely short pal if you wanna be certain stop the evap fans and let comp run if its charged correctly the whole coil will frost over.

Went back today and added additional charge to the fridge about another 300grams on top of the 150grams it states on the plate and the fridge is working fine.

[install monkey]

had a fujitsu system on r22, customer wanted all r22 off site, so reclaimed 1kg factory charge, 3mtr piperun,been working ok for 6yr- charged with isceon59 -1kg, suction dropped into a vac, had to stick another 1kg to get it operating correctly