AEC AP Series Large Dehumidifying Dryer - Manual (Page 21)

Large Dehumidifying Dryers Functional Description 20
Material Overdrying Protection
Material Overdrying Protection is an automatic system used to reduce the chance of over-
drying, and possibly melting, the resin in the drying hopper. Material Overdrying Protection
activates when the return temperature is above a set value, indicating that all the resin in the
hopper is dry.
The control system monitors the return air temperature and automatically changes the process
air setpoint to the SET BACK SETPOINT value when the return air temperature rises above
the set back temperature. The process air setpoint returns to normal when the return air
temperature falls below the SETUP TEMPERATURE value. The target values for
changing the process air setpoint can be adjusted on the Mat Protect screen.
Recommended Temperature Settings
Drying Temperature (ºF) 160 180 200 220 240 260 280 300 320 340 360
Setpoint 120 125 130 135 135 140 150 160 170 180 200
Figure 5: Material Miser/Air Balance Valve
Coupling
Temperature
Probe
Drying
Hopper
Valve
Proofing
Switch