Indication With Leds; Direction Of Action Switch - Samson 5857 Mounting And Operating Instructions

6.1.2.1 Indication with LEDs

The actuator with positioner has a red and a yellow LED which indicate the operating state of
the actuator through a blinking pattern. The LEDs are located underneath the cover on top of
the actuator (see Fig. 6-2).

6.1.2.2 Direction of action switch

The position of the direction of action switch determines the actuator's direction of action.
Î See Fig. 6-2.
− Switch position A: Direction of action increasing/increasing (>>)
The actuator stem retracts as the input signal increases.
− Switch position B: Direction of action increasing/decreasing (<>)
The actuator stem extends as the input signal increases.
Actuator stem extended
− For globe valves:
− For three-way mixing valves:
− For three-way diverting valves: Port AB à A closed, AB à B open
Actuator stem retracted
− For globe valves:
− For three-way mixing valves:
− For three-way diverting valves: Port AB à A open, AB à B closed
Flow pipe
Return flow pipe
Return flow pipe
Fig. 6-3: Operating principle of three-way mixing and diverting valves
EB 5857 EN
Valve closed
Port A à AB open, B à AB closed
Valve open
Port A à AB closed, B à AB open
Mixing valve for mixing service
AB
A
B
Diverting valve for mixing service
Flow pipe
A AB
B
For diverting service
Flow pipe
Return flow pipe
AB
For diverting service
Flow pipe
A
AB
B
Return flow pipe
Operation
A
B
6-3