122 ● gForce Ultra User Manual 10-2014
Go to the Analog Output 3 menu and adjust the fan speed to the desired low limit
operating point. In this example, the low limit is 30%. Change the “Mode” to “Manual”
and “Manual Value” to 3.00VDC (i.e., 0 to 100% equals 0 to 10VDC).
At this point, you will probably get a “No Airflow Alarm” on the dap4™ display. Also,
you will notice the green LED is ON at the current sensing relay because the fans are
running at a slower speed than original speed (i.e., drawing lower current).
Use the small flat blade screw driver to turn the potentiometer clockwise until the red
LED turns ON. Continue to turn the potentiometer another half turn to make sure that
the setpoint is slightly lower than the required setpoint. In this example, 3.00VDC.
When the fan speed returns to original speed (after 300 seconds) the “No Airflow
Alarm” should disappear.
The current sensing relay is now set and will trigger a “No Airflow Alarm” if for some
abnormal reason, the fan current drops to an unusually low point
10.7 Plug Fans
Maintenance is not required on EC motor/plug fan modules. The motors are sealed,
have maintenance free ball bearings and permanent lubrication. The only acceptable
service is replacement.
10.7.1 Electronically Commutated Motors
Electronically Commutated (EC) motors with “plug fans” are standard on all gForce
units.
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