update : RC group UNICO STD scewcomp

[wingman]

Just wanted to give a little update on my expierence with this chiller.

So I've been three days on site now and Oh boy have I found several things.

I mentioned earlier that I had an error 48 LD probe fail.
Once on site I hooked up my manifold on the liquid line and the suction line. Because such a probe would indicate a fault if it goes below 0bar. The manifold indicated there was a serious leak. (less than 2 bar on both sides.) First thing on my mind was to take out the (huge) fuses so the compressor would not start after I replaced the sensor (measured the probe and it was faulty)

Next thing I did was taking my leak detector and started probing the complete system(there was still refrigerant on the system). I found a leak on the low pressure side on the suction line filter between the two flanges. I removed the remaining refrigerant in a recuperation bottle. Obviously I had to change both seals between the flanges. One thing the people at RC group could have done better was the placement of the bolts from the suction line. No way you could descently remove the bolts from the suction line. Anyway I replaced both seals and closed down the system again.

I bought two small bottles of dry nitrogen. Put on a pressure of about 11 bar and leaktested with foam.

Guess what ... leak on the seal I had replaced, So I purged the nitrogen and started all over again. This time I added some leak lock .
Oh, and all you sceptic people about just using leak lock on R22 recheck the site from the manufacturer.

Charged up again to 11bar and with foam no more leaks. So far I was all happy and doing my little victory dance .

This was allready worth for 1 jour Checked my manifolds the day after .... . Leak .... arrggg. I just wanted to slam my head into the wall. Problem with this system is that it's for airconditioning and as a backup for a server room.

The other RC group chiller is running 24/7 and is used for a HUge server room in the basement and small server rooms on each floor of this building. One ventilator is stuck and has to be replaced So just in case we opened up the bypass of the water system so the large unit I am working on would help if the small one would trip on HP.

This time I was so pissed I wanted to find the leak, I had already spilled 15m³ of dry nitrogen. I closed down the discharge line and liquid line blocking out the condensor completly. Charged again to 5bar and sprayed foam on all flanges, capilary tubings etc. No leaks. .
There was so much background noise I turned down the other compressor and other HVAC equipment on the technical floor so I prehaps could "hear" the leak.
I heared a faint noise comming from the compressor so I investigated the compressor. Together with my co worker I opend up the top casing (insulation) and heared the noise much better. A dark patch on the top side of the electric connection box caught my attention. So my co worker opened the box en voilá fried copper wiring on a bed of chinese compressor oil and a leak .

Anyway I called the company that imports these machines. They will visit the site on friday, I am just Oh so curious what they have to say after asking me I was qualified to work on chillers ... Grrrr.

Again sorry for my terrible English

[Brian_UK]

Well done for finding the leak, just one thought though...

I hope that you were not putting that test pressure onto the compressor if it was a semi-hermetic as it will blow out the electrical terminal seals.

[wingman]

I might have confused you all but, ...

I've charged 500kPa (5bar) on the suction (approx. working pressure.) and 1100 kPa (11bar) on the discharge line. Test pressure of the compressor according the online documentation is 4110 kPa. (about 42 bar)

So yes I was aware of that

[Brian_UK]

OK, I'll take my Granny hat off now and go sit in the corner