Page 26
PCA Series Chillers
5 Microprocessor
Control
5-1 Introduction
Standard PCA Series chillers use a microprocessor-based PID controller. The controller
is a modular, self-contained unit that can slide from its mounting housing. It is factory
set and adjusted; no field adjustment to the internal controls is necessary.
PCA
Control Operation Range
Standard models
30°F to 65°F (-1ºC to 18ºC)
5-2 Setting the Process Water Temperature
To change the process water temperature set point:
•
Press the
Up Arrow button to raise the set point.
•
Press the
Down Arrow button to lower the set point.
5-3 LED
Indicators
PV or Process Value Numeric LED
During normal operation, the large red
PV
LED on the controller displays the actual
process temperature at the To Process thermocouple. It also lists parameter symbols
during setup and error messages if an error occurs.
SV or Set Value Numeric LED
During normal operation, the green
SV
LED on the controller displays the process set
point you want the chiller to maintain. It also displays parameter and pre-set function
values during setup.
OUT1 LED
The orange
OUT1
LED lights when the
control output
energizes the hot-gas bypass
solenoid valve.
