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View Full Version : reset the leaving chilled water on a carrier



dmaffei
12-22-2004, 08:08 AM
Has anyone done a chilled water reset on a Carrier Centrifugal 19dh? It has a 32sm. I was looking for any info on which brand of card they used or the resistance or the connection points on the chiller. I'm pulling out an Andover system that someone was actually controlling the vanes directly (which I never recommend) and I just want to reset the setpoint.

coolwes
12-28-2004, 01:58 PM
Actually, if it's wired in the vane control circuit properly, the system you describe does a good job of reset.
The key is not to bypass any of the 32SM safety functions and use the 32SM as a low chilled water temperature limit.
I used to do the control and reset with a B/C (Siebe) CP8102 controller and a return water sensor (since that reflects building load).
There is a way to fool the temperature bridge on the 32SM with some pots and relays wired in the circuit. But you can only get fixed steps of reset this way and it's easier to do it as described above.
Lots of luck, maybe some others have some ideas.