Data Sheet for Product

Technical Instructions SKD6xU Electronic Valve Actuators 24 Vac Proportional Control
Document Number 155-180P25
September 25, 2018
Page 8 Siemens Industry, Inc.
Manual Operation
Figure 12. The Manual Setting Knob in Manual and Automatic Position.
- Turn the manual setting knob clockwise for manual operation.
- A red indicator becomes visible as you begin to crank. Each complete revolution
(360°) is equal to 3/32-inch (2.5 mm) stroke.
- If a signal is sent to the actuator while it is in manual operation, the actuator will
move but the control will not be accurate.
- The valve cannot be commanded to its 0% position while in manual operation.
Automatic operation
For automatic operation the manual override knob must be in the fully closed position.
Turn the manual override knob counterclockwise until the red indicator disappears.
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.
The maximum rating for Class 2 step-down transformer is 100 VA.
• Since SKD6xU actuators require 20 VA, a maximum of four actuators can be
powered by one transformer (80% of transformer VA).
• Operating more than four SKD6xU actuators requires additional transformers or
separate 100 VA power supplies.
• The position output signal U will switch from 0 to 10 Vdc to 4 to 20 mA when a 4
to 20 mA input signal is selected and used on the Y terminal.