Technical Instructions
Pressure Independent Control
Document No. 155-773
SSD Series Electronic Valve Actuators
September 1, 2015
Page 6
Siemens Industry, Inc.
Manual Override
The actuator can be driven manually to any position between 0 and 1 with a 3 mm hex
wrench. The control signal from the controller, however, will take priority over any
manual position.
For manual positioning (without power), insert the 3 mm hex wrench in the center of the
position indicator. See Figure 7. The actuator will maintain its position until power is
provided or restored.
Figure 7. Manual Override Operation.
•
(A) Turn hex wrench counterclockwise to retract the spindle.
•
(B) Turn hex wrench clockwise to extend the spindle.
NOTE:
Do not perform manual override while the power supply is connected; the
actuator will not track accurately when the control signal is applied. A short
power off/power on sequence is recommended to recalibrate the SSD61U
actuator.
Wiring
•
Do not use autotransformers. Use earth ground isolating step-down Class 2 power
supplies.
•
Determine supply transformer rating by summing total VA of all actuators used.
•
It is recommended that no more than 10 actuators be powered by one transformer.
Figure 8. SSD81U Wiring Diagram.
WARNING:
Terminal connection “G0” is
Common, not ground.
Figure 9. SSD61… Wiring Diagram.
