AEC HE Mass Flow Series Drying hoppers - Manual (Page 37)

Page 36 HE
• CHE • BCHE Mass Flow Series Drying Hoppers
Graphic Panel Controls and Indicators
PROCESS BLOWER ON Indicator
The green PROCESS BLOWER ON indicator is lit when the process blower is operating.
PROCESS HEATER ON Indicator
The green PROCESS HEATER ON indicator is lit when the process air heater is on.
HIGH TEMPERATURE PROCESS AIR Indicator
The red HIGH TEMPERATURE PROCESS AIR indicator is lit when:
• The temperature sensed by the process air thermocouple is outside the alarm set value.
• The alarm relay energizes and all the heaters turn off while the blowers remain on.
The alarm mode and value are factory-set to track 25º above the process set point. The alarm
value, therefore, is set as a deviation from the process set point. When the temperature at the
process thermocouple returns to within acceptable range, the alarm output de-energizes and the
heaters turn on again automatically.
DRYING HOPPER LOW LEVEL ALARM Indicator
The red DRYING HOPPER LOW LEVEL ALARM indicator is lit during a low level alarm
condition.
DRYER OFF ON Switch
The DRYER OFF ON switch is used to start or stop the drying cycle after the disconnect switch
is placed in the ON position.
PUSH TO SILENCE Switch
Press the PUSH TO SILENCE switch to stop the alarm during an alarm condition.
6-2 Using the 1/16 DIN Temperature Controller
Some AEC/Whitlock dryers use a 1/16 DIN microprocessor-based PID temperature controller
for maintaining process air temperature. The controller is a modular, self-contained unit you can
remove from the mounting housing. All parameters except for the process air set point are
factory set and adjusted; normally, no field adjustment to the internal controls is necessary.