- Condition: The dryer has detected the mid grain temperature has exceeded the maximum allowable mid grain setting input into the controller.
- Alarm Action Taken: COOL DOWN
- Component: RTD (Resistance Temperature Detector)
- Location: On the outside of the dryer approximately two thirds the way down the heating chamber and is usually accessible from either a catwalk or ladder.
Tools Required for Service:
- Voltage/continuity meter (to check ohms)
- Small standard blade screwdriver (to open cover)
- Wire strippers (if replacing sensor or refreshing connection)
- Replacement small wire nuts or crimp connectors
Tech tip: (1000 ohms @70 degrees device)
After acknowledging the alarm, to prevent shutdown, the maximum midgrain temp setting can be temporarily increased to above the current reading to make the current alarm condition go away. Meanwhile, immediately reduce the selected heat plenum setting and/or increase the discharge rate to bring the mid grain temp down to an acceptable level.
Potential causes of this alarm condition:
- To high of drying temperature selected for commodity for initial moisture level of commodity
- To low of metering rate selected causing the commodity to remain in the heating chamber of the dryer too long
- Open circuit on RTD reading 350 degrees
- Corroded/loose connection
- Faulty RTD