Data Sheet for Product
Technical Instructions  OpenAir® Non-Spring Return Rotary Electric Damper Actuator 
Document Number 155-187P25  24 Vac – Modulating Control 
May 13, 2021 
Page 12  Siemens Industry, Inc. 
Wiring 
•  All wiring must conform to NEC and local codes and regulations. 
•  Use earth ground isolating step-down Class 2 transformers. Do not use autotransformers. 
•  The sum of the VA ratings of all actuators and all other components powered by one 
transformer must not exceed the rating of the transformer. 
•  It is recommended that one transformer power no more than 10 actuators. 
WARNING: 
All six outputs of the dual auxiliary switch (A and B) must only be connected to: 
•  Class 2 voltage (UL/CSA). 
•  Separated Extra-Low Voltage (SELV) or Protective Extra Low Voltage 
(PELV) (according to HD384-4-41) for installations requiring   
conformance. 
WARNINGS: 
Installations requiring   Conformance:  
•  All wiring for CE certified actuators must be SELV or PELV rated per 
HD384-4-41. 
•  Use safety-isolating transformers (Class III transformer) per EN61558. 
They must be rated for 100% duty cycle. 
•  Over current protection for supply lines is maximum 10A. 
Wiring Diagrams 
Each wire has the standard symbol printed on it. 
Table 4. 
24 Vac power supply 
0 to 10V modulating control 
Standard 
Symbol 
Function 
Terminal 
Designation 
Color 
1 
Supply (SP) 
G 
Red 
2 
Neutral (SN) 
G0 
Black 
8 
0 to 10V input signal 
Y 
Gray 
9 
Output for 0 to 10 Vdc 
position indication 
U 
Pink 
Factory-installed Options 
S1 
Switch A Common 
Q11 
Gray/Red 
S2 
Switch A - NC 
Q12 
Gray/Blue 
S3 
Switch A - NO 
Q14 
Gray/Pink 
S4 
Switch B - Common 
Q21 
Black/Red 
S5 
Switch B - NC 
Q22 
Black/Blue 
S6 
Switch B - NO 
Q24 
Black/Pink 










