The Air Switch is an in field adjusted device that senses air pressure when the fan is running. The factory setting is usually ok. The dryer is tested at the factory without grain therefore an adjustment may be necessary.
On a GSI Competitor single fan dryer the light above the fan switch illuminates and on a GSI multi fan dryer the fan switch illuminates when air pressure is sensed.
Air pressure must be sensed within 20 seconds of the fan starting or the dryer will shut down and the computer will display an error message “NO AIRFLOW”. Air pressure can only be sensed if the dryer is completely full of grain. The Air Switch senses pressure when the fan is up to about ½ of its normal speed. The air switch will stop sensing pressure when the fan has slowed to about ½ of its operating speed.
If the indicator light does not illumine or flickers you will get a “NO AIRFLOW” shut down.
With the dryer full of grain adjust the air switch by turning the adjusting screw on the face of the air switch to be more sensitive counter clockwise in ¼ or ½ turn increments. Turn screw until you have a steady light. If the fan switch light comes on before the fan is started turn the adjusting screw clockwise or it will take too much pressure to activate the switch.
Use the fan light as an adjustment indicator. When properly adjusted the light will be illumined without a flicker.
Tip: To avoid shutdowns temporarily bypass the air switch safety while making the adjustments, until the fanlight indicates steady air pressure.
To bypass the air switch on a Competitor single fan dryer move the computer dip switch number 8 to the left. Be sure to move back to right after adjustment. On a Multi fan dryer change the setting in the dryer setup "Air Switch Testing" to "NO". This resets automatically when the computer in rebooted.
It is crucial to reinstate the air switch safety as soon as the adjustment is made. Be sure!!! Never run the dryer without this safety.
TO TEST FIRE THE DRYER without grain follow the "air switch bypass" "tip" instructions or your manual or on the decal in the dryer panel.
Remember!!! DO THIS WITH CAUTION bypassing the air switch eliminates the safety.
Other Possible Causes for air pressure loss:
The dryer must always be full of grain while in the drying process. If the dryer is being unloaded faster than the fill auger is filling the dryer air will escape through the screens causing air pressure loss. Note: The fill auger must always fill the dryer faster than the unloading auger is taking the grain away.The fill auger may have loaded the dryer fast when first started but over the course of time the auger may slow down because of some restriction from leaves, chaff, straw or some other foreign material over the auger intake.
Although not common the filter on the air switch may be plugged or is wet or possibly even frozen. Service the filter.
