AEC Econo-Cool Chillers - Manual (Page 32)

AEC Water Temperature Control Units Page 31
Pressure Switch
A pressure switch built into each unit keeps the system from starting until the water
supply is turned
On and subjected to the minimum water supply pressure. This feature
protects the pump seal and the heater from damage through attempted operation
without water. The pressure switch is set at approximately 16 psig (110.32 kPa/1.10
bars) for 250°F (121ºC) units or 55 psig (379.23 kPa/3.79 bars) for 300°F (149ºC) units
prior to leaving the factory.
4-2 The Microprocessor Controller
The controller is an easy-to-operate microprocessor-based PID control device. When
the process reaches the set point, the PID control cycles the cooling valve and/or
immersion heater to maintain the proper leaving water temperature.
The controller has been fully factory tested. Set the desired process
temperature set
point and the
control does the
rest.
Built-in range of
operation on the
controller is 0°F to
250°F (-18ºC to
121ºC).
4-3 Controller Display
Figure 6
PV or Process Value Numeric LED
During normal
operation, the large
red
PV Process
Value 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.
Figure 6
Typical E5CK Microprocessor Controller
PV
SV
OUT1
OUT2 MANU STOP RMT AT SUB1
AT
E5CK OMRON