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Installation
4.2.2
Position After Failure
The position of the actuator after a failure depends on the:
1.
Principle of operation (see paragraph 4.3)
2.
Assembly codes (see paragraph 4.4)
3.
Kind of failure. Refer to the table below.
Table 5.
Position After Failure
Principle of
Operation
Assembly Code
Kind of Failure
Position
Double-Acting
Actuator
Pressure
Not defined
Signal
Closed
Supply Voltage
Closed
Pressure
Not defined
Signal
Open
Supply Voltage
Open
Single-Acting
(Spring-Return)
Actuator
Pressure
Closed
Signal
Closed
Supply Voltage
Closed
Pressure
Open
Signal
Open
Supply Voltage
Open
4.3
Principles of Operation
4.3.1
Solenoid Valve
All actuators can be either piped with solid or flexible tubing with the solenoid valve
mounted remotely from the actuator or by mounting a VDI/VDE 3845 (NAMUR) designed
solenoid valve DIRECTLY onto the NAMUR mounting pad on the side of the actuator.
Figure 4
Typical solenoid operation
A
B
A
Spring-Return Operation
Double-Acting Operation
CW
CW
10
September 2017
Installation, Operation and Maintenance Manual
DOC.IOM.EF.EN Rev. 7
Section 4: Installation