Product Overview

MT Series SSC Electronic Valve Actuator, 24 Vac Floating (3-Position) Control Technical Instructions
Document Number 155-314P25
August 1, 2007
Siemens Building Technologies, Inc. Page 5
Wiring
Use earth ground isolating, step-down Class 2 transformers. Do not use
autotransformers.
Determine supply transformer rating by summing total VA of all actuators used. The
maximum rating for a Class 2 step-down transformer is 100 VA.
Do not power more than 10 actuators by one transformer.
CAUTION:
Terminals must be properly wired for correct function and full life of the
actuator.
Wiring Diagrams
NEUT
CONTROLLER
ACTUATOR
EARTH GROUND
ISOLATING CLASS 2
TRANSFORMER FOR
24 Vac POWER
120 Vac
1
0
Y2
Y1
G
24
Vac
EA0795R1
Y2…Retracts actuator shaft
Y1…Extends actuator shaft
G System potential
Figure 4. SSC81U Non-Spring Return.
EA1234R1
NEUT
CONTROLLER
EARTH GROUND
ISOLATING CLASS 2
24 Vac TRANSFORMER
120 Vac
24 Vac
ACTUATOR
G
Y2
Y1
G0
1
0
0
Y2…Retracts actuator shaft
Y1…Extends actuator shaft
G… System potential
G0…System neutral
Figure 5. SSC81.5U SR Neutral.
EA1235R1
NEUT
CONTROLLER
EARTH GROUND
ISOLATING CLASS 2
24 Vac TRANSFORMER
120 Vac
24 Vac
ACTUATOR
G
Y2
Y1
G0
1
0
0
Y2…Retracts actuator shaft
Y1…Extends actuator shaft
G… System potential
G0…System neutral
Figure 6. SSC81.5U SR Hot Switch