We have just completed a YK teardown in our shop and this being my first one I have a few questions. The compressor was torndown for a number of reasons......excessive excelleration time on startup, oil loss and very difficult to spin the compressor coupling with the motor disconnected.
The excelleration issue was obvious.....one of the vanes was open and the ball joint had come out of the ring. Any thoughts on how this may have happened....the slot is not deformed and the ball joint went back in with no issues.
My next question has to do with the laby seal areas on the impeller. The seal area on the impeller inlet is not smooth but it is grooved as though the floating laby seal has ground itself into the impeller. The laby does float but the grooves in the laby are ground down and this part of the system needs replacing. The seal area on the balancing piston looks very much like the impeller eye but it is so perfect it looks like the grooves were machined into the impeller. Again the actual balancing piston does float and the grooves are worn out. I am having trouble determining the reason for the impeller issues because the bearings are not that bad......of course York info does not give bearing clearances so my observations are based on teardowns of other manufacturers chillers. The impeller shows no other signs of extreme wear except the two seal areas.
Oil loss occured without the chiller even running ( this chiller has periodic seal lube). The oil cooler is refrigerant cooled and is under test.....any other thoughts where to look.....nothing obvious in the compressor.
All thoughts are appreciated.........................wayne