Settings (J3)
Trigger Speed (WA): Use this jumper to set the trigger speed. Select a trigger that is 40 to 50% of rated speed.

Position L = 1000 PPM
Position M = 2000 PPM (Factory Setting)
Position H = 4000 PPM

Since fan tachometer circuits are designed with one, two, or even more pulse outputs per revolution, settings are listed in pulses per minute (PPM) rather than revolutions per minute (RPM). Given the fan’s rated speed (W) and number of pulses per revolution (N), use the following formula to select the trigger speed (WA):

WA = W x N x 0.4

For example, a 3300-RPM fan with two pulses per revolution would have a trigger speed (WA) of

WA = 3300 RPM x 2PPR x 0.4 = 2640 PPM

Since the 2000 PPM trigger is closest, set jumper J5 to the “M” position. The alarm trigger accuracy is +/- 20%.