VSD-1C
Page 6
The VSD-1C module uses a 0-10 Volts or a 4-20 mA signal to make a fan modulate.
User can adjust the fan Minimum Speed with the potentiometer located inside the
module box on the electronic board (refer to figure 2). That Minimum Speed
potentiometer is used to adjust the speed when the input is at its lowest value.
User can also set how the fan will operates when the input signal is at or below 5%
of its total range. Refer to the logic diagrams at figure 3 to know the exact values and
behavior of the different switches configurations. The fan can either continue to run
at Minimum Speed (Shutoff 5% set to OFF) when the input has reach its minimum
value or can stop when the input reach 5% of its total range (Shutoff 5% set to ON).
With the Shutoff at 5% switch set to ON, a differential is applied in order to avoid
equipment wear. Refer to figure 3 for the exact value of the differential. Also refer to
figure 2 for the location of the Shutoff 5% switch.
Another switch also located on the electronic board will select if the input is a 0-10
Volts (0-20 mA) or a 2-10 Volts (4-20 mA) signal. Refer to figure 2 for the location of
the Input Range switch.
Finally, a jumper (JP1) must be set to determine the Input Type used. Two types are
available which are: 0-10 Volts (jumper on the 2 left pins) and 0-20 mA (jumper on
the 2 right pins). Refer to figure 2 for the location of the Input Type jumper.
Here is a description of the VSD-1C operation:
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If the Shutoff 5% switch is set to OFF, the fan will run continuously at its
Minimum Speed when the input reads it lowest value. If the Shutoff 5% switch
is set to ON, the fan will stop when the input is at or below 5% of its total range. A
differential is applied to the 5% value. Refer to figure 3 for the exact value of the
differential.
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If the input reads above its minimum value (or 5% if the Shutoff 5% switch is set
to ON), the fan will modulate from its Minimum Speed to 100% of its maximum
speed. The full speed will be reached when the input reads 10 Volts or 20 mA.
