Burrah Boy
30-04-2012, 02:03 PM
Hi all,
The problem we are having with this chiller is that all the oil is being sucked out of the sump. The machine then gets noisy, metal to metal. It then starts flooding the oil back into the screws, and you can actually hear the compressor labouring as it is dealing with a floodback of oil. There is also then a great deal of foaming, obviously.
These are fitted with the McQuay screws.
What I think is happening is that the PID is taking too long to make adjustments, and when it does give commands for compensation, the EEV opens too much and overshoots the target evap temp.
This is a new system that we are trying to get to operating properly.
Our condensing water is coming in at 28 degC and ELWT is 7 degC.
The factory defaults havent really been fiddled with, but maybe a few tweaks on the P.I.D. might help?
Any Ideas please.
Regards
The problem we are having with this chiller is that all the oil is being sucked out of the sump. The machine then gets noisy, metal to metal. It then starts flooding the oil back into the screws, and you can actually hear the compressor labouring as it is dealing with a floodback of oil. There is also then a great deal of foaming, obviously.
These are fitted with the McQuay screws.
What I think is happening is that the PID is taking too long to make adjustments, and when it does give commands for compensation, the EEV opens too much and overshoots the target evap temp.
This is a new system that we are trying to get to operating properly.
Our condensing water is coming in at 28 degC and ELWT is 7 degC.
The factory defaults havent really been fiddled with, but maybe a few tweaks on the P.I.D. might help?
Any Ideas please.
Regards