View Full Version : Dual compressor chiller - set points?

06-04-2014, 10:36 AM
We have a dual compressor glycol chiller that runs off a basic Ranco controller which allows separate set points/differentials for each compressor. We're just starting to push the chiller closer to its limit, so we hadn't put that much thought into how to set these efficiently. Right now the first compressor is set to 27 w/ a 2F dif and the second is set at 27 w/ a 3F dif. My thoughts were that the 2nd compressor would only kick on when the whole system is under heavier load, but how ideal are these actual numbers?

Also, this is the first time we've had issue with the glycol warming up significantly because of the warmer weather and especially when calling for cooling on the cold liquor tank. Any tips/tricks/general advice yall could give as how to manage these issues?


06-04-2014, 01:01 PM
Generally speaking if you have adequate capacity you will not run your second stage to the same setpoint as first but at least 2 degrees higher.
So 1st stage at 28 and second at 30, both with 2 degree differential. This is old school convention.