Bad tail bearing. Scrap's going for $.20/lb for mixed metal . That said, you don't give any readings other than oil pressures, so I'm having to take your word that it's not flooding.
got a 15 year old 30 ton recip compessor on a 120 ton air cooled chiller. tripping oil safety. oil level good , oil switch good , have low discharge oil pressure , 70 psig. have low net oil pressure 8-10 psig. other compressors similar to this have 100-110 discharge oil pressure and 30-50 net . i replaced oil pump but have same readings. have vibration coming from compressor . not slugging . do you think i should spend effort to open it up and investigate or should i quote replacement? i am leaning toward replacement , just not sure if a compessor rebuild is cost effective in today's world.
Bad tail bearing. Scrap's going for $.20/lb for mixed metal . That said, you don't give any readings other than oil pressures, so I'm having to take your word that it's not flooding.
did you check the oil pickup screen for debris?
The math just does not add up to overhaul a compressor that size. You would have four days in it and then the liability of it being right. Get a rebuilt one or new one with a warranty. Better for you better for the customer.
Get the rebuilt.
Never give up; Never surrender!
isnt the oil screen in the oil pump assembly ? pressures are fine . 15 subcooling 10 superheat . this is mcquay. literature said beteen 8 and 12 superheat. i am going to quote new compessor. thanks for input!
Nope.
Copelands have an oil pickup screen in them.
the screen is in the compressor sump. I would definetely check it before selling a compressor.
If your customer calls someone else to double check your quote, I would hate to have them clean a sump screen for an hour's labor and fix their problem while you wanted $$$$$$$$$$$ for a new compressor.
ok, i will check it to make sure, thanks.
it's on the bottom left
its the large 1 3/8 bolt on the bottom left, take it off and pull the screen out.
For kicks and giggles did you try reverse spinnin this baby and see if any thing changes?? In regards to rebuild, they have it right.. Quote a reman
Did anyone ever change valve plates on the compressor? You can tell because the edges of the new plates will be unpainted and/or rusted. I think you have a broken rod caused by a valve plate that had a broken discharge valve. When that valve fails there is insufficient load reversal on the piston pin area of the rod and piston. This causes accelerated wear in that area which over time will elongate the pin hole in both rod and piston. When proper valve action is restored, (a new valve pate) the excessive wear continues until the rod breaks. The out of balance condition (5 rods rotating instead of 6) creates the vibration that you notice. If you don't correct the problem you will break lines and lose refrigerant. The problem isn't a broken rod, and it isn't a bad valve plate. The problem is that someone replaced a valve plate and didn't find out why the compressor slugged the valves out in the first place. Change the parts and don't fix the problem and you will change the compressor.