3
P906C PROPORTIONAL DIFFERENTIAL PRESSURE CONTROLLERS
WIRING
Disconnect power supply before beginning installation to prevent electrical shock and equipment
damage. All wiring must comply with local electrical codes and ordinances. See Fig. 3 and 4 for
typical system hookup and wiring.
Fig. 2. Recommended Tubing Fittings
Fig. 4. Typical Wiring Fig. 3. Typical System Hookup
OPERATION
Pressure Difference Adjustment
Because these controllers have such a wide
variety of applications, they are adjusted on
the job with the system in operation.
IMPORTANT
The device controls the difference between
the pressures exerted upon the 2 bellows,
not the gauge pressure.
1. Connect a pressure gauge with adequate
range to each element assembly.
2. Connect the differential pressure controller
and gauges to the pressure points to be
controlled.
3. Turn the pressure difference adjustment
screw counterclockwise (↖) until the scale
indicators reach the low (minimum) end of
the scale (Fig. 5).
4. Turn the throttling range adjustment screw
until the throttling range indicator is midway
between C and D on the throttling scale
plate.
NOTE: Do not go beyond the point at which
the linkage begins to show slack.
5. Apply typical operating pressures in
sequence to the left and right elements
(high and low pressure sides,
respectively). Turn the pressure
difference adjustment screw clockwise
() until the desired differential pressure
is reached.
6. Adjust the throttling range as needed.
To increase the throttling range, turn the
throttling range adjustment screw
clockwise (). To decrease the
throttling range, turn the throttling range
adjustment screw counterclockwise (↖).
7. Apply pressures through a typical cycle
while checking the differential pressure
controller operation. Readjust settings if
necessary. If there is any indication of
short cycling or a hunting condition,
increase the throttling range setting.
8. When the system operates as desired,
mark the settings on the scaleplate.
