Samson 3730 Series - Determining the fail-safe position

7-2 EB 8384-3 EN
Start-up and conguration
During the start-up phase, operation on site is unrestricted, yet write access is limited.
Sequence for start-up:
Action Section
1. Determine the fail-safe position. 7.1
2. Adjust the volume restriction Q. 7.2
3. Limit the signal pressure. 7.3
4. Check the operating range of the positioner. 7.4
5. Initialize the positioner. 7.5
6. Congurethepositionerbysettingfurtherparameters. 7.6
7. Positioners with inductive limit switches:
Adjust the inductive limit switch.
7.7
7.1 Determining the fail-safe position
Denethefail-safepositionofthevalve(0%)takingthevalvetypeandtheactuator'sdirec-
tionofactionintoaccount.PositiontheAIRTOOPEN/AIRTOCLOSEslideswitchaccording-
ly:
− AIR TO OPEN setting
Signal pressure opens the valve, e.g. for a fail-close valve
The AIR TO OPEN setting always applies to double-acting actuators.
− AIR TO CLOSE setting
Signal pressure closes the valve, e.g. for a fail-open valve
For checking purposes: after successfully completing initialization, the positioner display
mustread0%whenthevalveisclosedand100%whenthevalveisopen.Ifthisisnotthe
case, change the slide switch position and re-initialize the positioner.
The switch position is prompted prior to an initialization. After an initialization has been
completed, changing the switch position does not have any effect on the operation of the po-
sitioner.
Note