Coolmaster CU200, leaking

Need some help from you lesser beings who deal with these small "wanna be" cooling units :D

did that hurt? sorry :)


ok, all jokes aside.


I have no experience with small compact cooling units, other than when some relative asking me to look at their fridge/freezer I give them the "buy a new one, it's cheaper"

My whole family has been bugging me now for weeks to take a look at my aunts "cooling cabinet" it's a cabinet fitted in a corner, not quite walk in but almost.

the cooling unit is a Coolmaster CU200, it's out of production and a new cabinet costs in the range of $2000 or £2300, so I broke down and said I'd have a look at it :/

anyways.

the unit wont hold a vacuum, get it down to 10 mbar (cant get it lower) and in two minutes after I shut the valve for the pump it rises to over 150mbar, so there is a leak, and it's large (me thinks).

so I pressurize it with nitrogen at 10 bar, and in 24 hours it drops to 9.9 bar.

I've gone over it with soapy water, halogas (the propane thingymajigg) detector and a beeper (the electronic beeper that goes off if there is a leak within three miles), and nothing.

should I just recharge it and tell them to call me when it stops cooling (or starts icing up) again, or call it a gonner?

I was thinking about submerging the whole thing in water, but that means stripping off all the electrics...


do you have any tips?

I have heard rumours off some kinda stuff you mix with the ***** to seal small leaks (something along the line of the stuff you put in your cars radiator), but cant find anything on the net.


all help greatly appreciated.


Cheers

Tycho

Quote:

---

the unit wont hold a vacuum, get it down to 10 mbar (cant get it lower) and in two minutes after I shut the valve for the pump it rises to over 150mbar, so there is a leak,

---

Sounds like a leak or a fault with the vacpump

Quote:

---

so I pressurize it with nitrogen at 10 bar, and in 24 hours it drops to 9.9 bar.

---

Sounds like a small leak or a fault with your vacpump :)

Quote:

---

Originally Posted by frank

Sounds like a leak or a fault with the vacpump



Sounds like a small leak or a fault with your vacpump :)

---

No, nothing wrong with my pump :)

yes, there is a tiny leak somewhere, but what are my chances of finding it? Never worked on such small unit before

Was the system out of gas when you started or did you have to take the gas out?

Reason I ask is - has the leak allowed air to be drawn in with the resultant moisture; if yes then the pressure rise could be due to moisture as well as a leak.

What was the original gas? Are it's molecules smaller than OFN ?

If its R134 , then molecules are smaller and will leak.

Are there any brass fittings on it? Like a soldered expansion valve.

If it has then a hot flame on the brass makes small microscopic holes which will leak over time

do you have any tips?

I have heard rumours off some kinda stuff you mix with the ***** to seal small leaks (something along the line of the stuff you put in your cars radiator), but cant find anything on the net.


all help greatly appreciated.


Cheers

Tycho[/QUOTE]

You could recharge it & introduce some tracer dye ! :)

Quote:

---

Originally Posted by Brian_UK

Was the system out of gas when you started or did you have to take the gas out?

Reason I ask is - has the leak allowed air to be drawn in with the resultant moisture; if yes then the pressure rise could be due to moisture as well as a leak.

What was the original gas? Are it's molecules smaller than OFN ?

---

it was not running on vacuum, gas is R-134a

I have to withdraw my statement on the pressure drop, since this morning it was back to 10 bar (will blame the difference on temperature, as it was warmer today)

it will not hold a vaccum tho

Quote:

---

Originally Posted by Aiyub

If its R134 , then molecules are smaller and will leak.

Are there any brass fittings on it? Like a soldered expansion valve.

If it has then a hot flame on the brass makes small microscopic holes which will leak over time

---

no brass fittings, capillary tube.

and I left the ***** that was left inside the system when pressuretesting with the molecular size in mind

Quote:

---

Originally Posted by stevo

You could recharge it & introduce some tracer dye !

---

good ide, will do that.

but the stuff I was looking for is something alog the lines of radweld, or cimilar to putting cinnamon on your radiator if you have a small leak.

thanks for all your input guys, really appreciated


cheers

tycho

Quote:

---

gas is R-134a

---

Quote:

---

no brass fittings, capillary tube.

---

Blockage????

Chillin:) :)

Quote:

---

Originally Posted by chillin out

Blockage????

Chillin:) :)

---

:D I thought that particularly on R134a, change the filter, vacc out and weigh the charge back in, if it does not contain moisture there is a blockage and under deep vac it is still drawing small amounts of gas through the system or fit an access valve by the filter drier and vac it there. Not familiar with the cabinet so dont know if its expansion valve or capillary.

Tyco:)
what about using a different trace gas, one eaiser picked up (R22), still legal to do this in some parts of the world, we won't tell on you:D

You could also add nitrogen and top off with Helium, this will find the holes that only HFC's will go out thru.

Kind Regards. Andy:)

Disregard that post. do not under any circumstances boost the pressure in a domestic unit to 500psi. this is an invitation for serious injury and/or death.

Quote:

---

Disregard that post. do not under any circumstances boost the pressure in a domestic unit to 500psi. this is an invitation for serious injury and/or death.

---

I agree.

Do not do this. I doubt very much if a plate evap will take this sort of pressure, even if its in perfect condition.

Many years ago I done this and it blew the evap up like a ballon.

Chillin:) :)

Quote:

---

Originally Posted by chillin out

I agree.

Do not do this. I doubt very much if a plate evap will take this sort of pressure, even if its in perfect condition.

Many years ago I done this and it blew the evap up like a ballon.

Chillin:) :)

---

Now thats magic. if mr daniels could blow an evap. up like a balloon i think his words would be "youll like it, but not a lot".

Hi there..

we was the service agent for norcool who produced this unit...

This unit had a inherited flaw it will never work correctly in the uk die to low ceilings ie heat cannot get away causing compressor to run very badly.

They did often leak on the evaporater but these units run at 15psi running pressure using R134a.

As soon as norcool left uk we had a headache for 6 months b4 calling it a day as these units will drip water inside of there housing and all over the inside floor.Nothing can silve it.

New unit could still be purchased that you insert through the top of the unit.
They brought out another version which stood in the back of the unit still had problems.

Quote:

---

Originally Posted by expertcat

Hi there..

we was the service agent for norcool who produced this unit...

This unit had a inherited flaw it will never work correctly in the uk die to low ceilings ie heat cannot get away causing compressor to run very badly.

They did often leak on the evaporater but these units run at 15psi running pressure using R134a.

As soon as norcool left uk we had a headache for 6 months b4 calling it a day as these units will drip water inside of there housing and all over the inside floor.Nothing can silve it.

New unit could still be purchased that you insert through the top of the unit.
They brought out another version which stood in the back of the unit still had problems.

---

Thanks for the heads up :)

I didnt find the leak, it wouldnt hold vacuum, but with a *****/n2 gas mix if held the pressure.

another problem was that the thermostat was halfway submerged in water from evap dripoff, so the unit just kept on going and going and going in spirit of the duracell bunny :)
only drain point for the box that ecased it was the hole where the adjusting knob went through.

The unit belongs to my aunt and uncle, so I fitted a manometer on the suction line so they can keep an eye on it, and I'll just drop by and recharge it when needed.

Hi
Wondered if someone could tell me why this unit is so noisey. Always has been, makes a loud humming noise. It hasn't worked very well with the hot summer. Customer has had to throw a lot of food away. Can this be adjusted to make it less noisy, would a replacement be quieter? These are expensive to say how they perform?

Any constructive comments or suggestions greatly appreciated.

Harry:)

I've been the owner of a CU200 corner unit for 4 years now. I inherited it from the previous owner who was a professional meatseller in Smithfield's market in London. I am on my second CU200 unit. The first just died.

In answer to your query, no, a new unit will not be any quieter and, yes, they are very expensive.

My problem is that the thermostat has stopped working so that the unit is constant chill. I read above on this forum that the thermostat could stop if it gets submerged with water, is that the case?

Quote:

---

My problem is that the thermostat has stopped working so that the unit is constant chill. I read above on this forum that the thermostat could stop if it gets submerged with water, is that the case?

---

When I took it apart, I found that there were no drain holes in the plastic case that holds the thermostat apart from the hole where the adjustment knob comes through, so water dripping from the evap. filled it up till the thermostat was half submerged thus it stopped working.

drilled a hole in the casing and fit a new thermostat, works like a charm, apart from that darn leak :)

.............and can you tell me how I can access the thermostat so I can check if its submerged or not. Currently got the whole unit running on my kitchen table so I can give it its annual vacuum clean, but can't see how to get to the thermostat :confused: