8
Adjustment Guide:
Negative Logic
Negative Logic
operation
operation
• Plug driver unit onto valve coil to be driven.
• Remove ‘DFC-3’ securing screw
• Remove ‘DFC-3’ opaque lid to reveal internal adjustments.
• Remove or cut link A.
•
Ensure command PWM signal is set to 90%.
• Ensure that all connections are correct and secure.
• Turn I Min potentiometer 1 turn Anti-Clockwise ( Minimum ).
• Turn I Max potentiometer 20 turns Clockwise ( Maximum ).
• Turn ‘Dither frequency’ potentiometer to approx. mid position.
• Apply 24VDC ( +18 - +32VDC absolute Maximum ) to the driver plug.
• Slowly increase command to approx 100% of maximum PWM.
• Use the I Min adjustment to give minimum motor speed required.
• Slowly decrease command signal to 10% of maximum setting.
• Adjust I Max until desired motor maximum speed is achieved.
• Check that ‘Output ON’ led is functioning proportionally by varying the
command signal.
• DFC-3 Plug top controller700-00027-0 is now set.
• Replace opaque lid carefully ensuring that seal is maintained.
• Replace securing screw and tighten
• Do not overtighten or lid damage is seen.
• Unit is now ready for continuous application use.
• Adjust Dither frequency to suit valve product being driven.
• Fully Anti-clockwise = approx. 100Hz
• Fully Clockwise = Approx.... 250Hz.
• Suggested setting is MID position.
• Set command to minimum PWM %.
• Isolate plug from +24VDC supply.
700-00027-0, DFC-3 Plug Top Driver Unit.
Negative Logic operation
means that the output
current is inverse to the input
command signal.
i.e. 0% PWM = Max O/P
100% PWM = Min O/P
This option is intended for
use when the input PWM
signal is conforming to
Negative logic as above.
In this configuration, if the
power supply fails, the fan
unit will default to the
Minimum speed ( see note
below ).
For this option to be
activated, the user must
Remove
link A, the location
of which is shown on page 4
of this manual.
CAUTION:-
The A link, once removed,
CANNOT be replaced
easily.
NOTE:-
At all times during the set-
up procedure, it is
assumed that a reverse
acting pressure control
valve is being used.
For other logic or valve
types, please ensure the
input output logic is
correct before connection
and operation.
