Who's a 1996's Bitzer 2N 5.2. This "li'l" fella is placed in a loft, working for some freezer cabinets (SESAM-cabinets) out in the store 20 meters away, on my half-year inspection round for this machinery (and some more machines to other refrigerator boxes in the store) I saw "Frosty" completley frozen at the suction line eliminator, all the way to the motor housing, Lots of Ice had grown on the suction line ack., flashing sight glass and almost empty in the reciever tank (18 kg of R404A) and low pressures (-36 C and +30 C) Found some leaks at the SESAM cabinet by the magnet valves, fixed'em and filled some more refrigerant. Started filling... 8 kgs and still flashing, filled 4 kg more, still flashed after total 12 kg, made a pumpdown (closed outgoing from the reciever) Yep, the tank told me about a very high level. Everything's fine i supposed. Good pressures as well.
Went down to the store for a last check... WTF... No cold air from the outlets... Began to think "shiet", went up to the machinery again, Frosty larmed for Low oil pressure. The oil sight glass... Empty. Now what i thinked?! Called a job friend (have some more experienced job friends I can call if I'm hitting patrol as a "greenhorn") He came there with some oil, meanwhile, I took out some refrigerant from the system ('bout 11 kg) and filled it into a clean can.
After much work we got the system started again and the oil went back into the compressor, took away the ice that hided both suction filter and suction line ack. But it started to get frosty at the suction line faster than pronouncing the word "holy ****", filled up 5 kg of ref.
Went back the day after, measured some temperatures and pressures, wrote'm down and told the guys at the company the values I'd got. "Tttttt, that's a saga youre telling us, you haven't measured right" So yesterday i went back, measured again while I had Telefon contact and told the values. After a while the job friend showed up (same as earlier) and he was same confucius as I was. 2 sections on the Sesam cabinet, one section gave me the values -14 C by the TEV's bulb, -20 C in evaporation, and +8 C at the sution line outside the cabinet, the other cabinet gave me -11 C at bulb, -19 C in evap and -20 C at the suction line outside the cab. BIG WTF... We both scratched our heads so the dandruffs swirled in the air or anything like that.
Heard that one TEV flushed really much, so we replaced that li'l bastard, and started Frosty again, still flushed. Adjusted the TEV to totally closed, still flushing. I Expected the nigt before we changed TEV that it could be a faulty suction gas heat exchanger, but once more "It's unpossible" from my job friends, haha i love my job .
On monday we are going to disect the cabs and see if the heat changers are possibly to change to new ones or just replace them with some copper pipe, if out of stock.
This is a pair Pics showing frosty one day after "defrost", now you know why I'm calling him "Frosty"
/Patrik from Sweden