- Condition: The dryer has detected fan #3 is not running.
- Alarm Action Taken: COOL DOWN
- Component: Air Pressure Switch
- Location: Usually in the upper left corner of the high voltage cabinet.
Tools Required for Service:
- Voltage/continuity meter
- Small standard blade screwdriver (wiring terminals and adjust setpoint)
Tech tip: (115 vac circuit) (Vacuum switch)
This alarm occurs if the vacuum switch does not close its contacts when the fan is running. The fans are monitored by a vacuum pressure switch with a copper tube that runs from the air inlet side of the fan out the dryer and down to the pressure switch.
When fans are running, there should be 115 vac in and out of the switch when functioning properly.
To adjust switch, with fans running, turn adjustment screw all the way in. Air pressure switch light on controller for fan #3 should be out. Back out screw until light just does come on. Continue backing out screw 1 full turn and stop. Unit is now adjusted.
Potential causes of this alarm condition:
- Fan did not come on
- Copper tubing is plugged, broken or pinched
- Switch out of adjustment
- Faulty switch
- Poor or corroded wiring connection