we have two chillers of York YCAS 0425EB50. Each has two compressors. On Chiller 1, System 1 compressor takes up to 90% load and system 2 compressor takes up to 50%.
on chiller 2, system 1 compressor takes up to 50 amp(49-50%) load and system 2 compressor takes around 73 amp(max).
we have tried to run only one compressor to see if it takes full load. It does not. I have checked the service mode settings, but it is programmed as 106 amp=100%. I changed the value to 120 amp=100%, yet there was no change in the amperage.
Our leaving temp set point is 6.7 deg c, even when the leaving temp is 14 or 15 deg c there is no increase in compressor load.
One thing that we have noticed that the difference between the leaving and return temp is always around 2deg c or 4-5 deg F. The maximum we observed was 6 deg F. Does the compressor loading depends on the temp diff between leaving temp and the set point or between leaving temp and return temp?
Could anybody please give me any idea why this is happening or what else we can check. Please let me know if you need any other information.