Microswitches; Pneumatic Connections; Information On Double Acting Actuators With Spring- Return Mechanism - ABB PositionMaster EDP300 Commissioning Instruction

6.6.3 Setting the mechanical binary feedback with 24 V

microswitches

1. Loosen the screws for the housing cover and remove it.
2. Select "Manual Adjustment" operating mode and move the
valve by hand into the desired switching position for
contact 1.
3. Set maximum contact (1, lower washer).
Fasten the upper washer with the special adjustment
retainer and rotate the lower washer manually.
4. Select "Manual Adjustment" operating mode and move the
valve by hand into the desired switching position for
contact 2.
5. Set minimum contact (2, upper washer);
Fasten the lower washer with the special adjustment
retainer and rotate the upper washer manually.
6. Connect the microswitch.
7. Attach the housing cover and screw it on to the housing.
8. Tighten the screws so that they are hand-tight.
26 CI/EDP300-EN Rev. C | PositionMaster EDP300
6.7

Pneumatic connections

NOTICE
The positioner must only be supplied with instrument air that
is free of oil, water, and dust (in gas configuration with dried
natural gas).
The purity and oil content must meet the requirements of
Class 3 according to DIN/ISO 8573-1.
NOTICE
Damage to components!
Contamination on the air pipe and positioner can damage
components.
Dust, splinters, and any other particles of dirt must be blown
off the pipe before it is connected.
NOTICE
Damage to components!
Pressure above 10 bar (145 psi) can damage the positioner
or actuator.
Provisions must be made (e.g., use of a pressure regulator)
to ensure that the pressure does not rise above 10 bar
(145 psi), even in the event of a fault.
6.7.1 Information on double acting actuators with spring-
return mechanism
On double-acting actuators with spring-return mechanism, a
pressure that significantly exceeds the supply air pressure
value can be generated during operation by the springs in the
chamber opposite the springs.
This may damage the positioner or adversely affect control of
the actuator.
To eliminate the possibility of this occurring, it is
recommended
to install a pressure compensation valve between the
springless chamber and the supply air for these types of
applications. It enables the increased pressure to be
transferred back to the air inlet line.
The opening pressure of the check valve should be < 250
mbar (< 3.6 psi).