AEC WD 350 through WD3000 Dehumidifying Dryers - Manual (Page 38)

5-5 Level 2 Process Air Temperature Controller
Your AEC/Whitlock dryer uses a microprocessor-based PID controller for maintaining process
air temperature. The controller is a modular, self-contained unit that can slide out from the
housing. All parameters except the process air set point are set and adjusted at the factory; no
field adjustment to the internal controls is normally necessary.
Figure 14
Level 2 PLC Controller Details
1 8 0
1 8 0 SV
PV
OUT STOP HB
ALM2 ALM1
ºF
Output indicator
Stop indicator
Mode key
Level key
Not used
Down key
Up key
Not used
High temperature alarm indicator
Process air temperature set point
Process air temperature
5-6 Level 2 Temperature Controller LED Indicators
Process Value Numeric LED —— PV ——
During normal operation, the red process value ( PV ) numeric LED indicator displays the process
temperature at the To Process thermocouple. It also lists parameters during setup and error
messages if any errors occur.
Set Value Numeric LED —— SV ——
During normal operation, the green set value ( SV ) numeric LED indicator displays the process
set point you selected for the dryer. The dryer then maintains this set point temperature. This
LED indicator also displays parameter and pre-set function values during setup.
ALM1
High Temperature Alarm Indicator
The ALM1 high-temperature alarm indicator lights when the process temperature exceeds the set
point temperature by more than the alarm deviation value. This alarm output de-energizes the
heaters. Heaters re-energize when the temperature falls within the acceptable range.
WDMR and WDFR Series Dehumidifying Dryers Page 37