3 NM SERIES SPRING RETURN DIRECT COUPLED ACTUATORS
31-00141M—06 8
Fig. 18. Wiring for SYLK BUS control with separate 
transformers, MS3103.
OPERATION
The actuator is designed to be used in ventilating and air 
conditioning installations to operate valves, dampers, 
ventilation flaps and louvers. (For ratings, see the 
Specifications section.) If the power fails, the actuator will 
spring return to the fail safe position.
When using a proportional controller and actuator is set to 
(0)2 - 10 position, the actuator drives toward its fully open 
position when the input signal increases; the actuator 
drives toward the fully closed position when the input 
signal decreases. The actuator stops when the input 
signal reaches the desired proportional control point. This 
operates in reverse when set to a 10-2(0) position.
IMPORTANT
The actuator is designed to respond to DDC 
Controller instantaneous contact closures. Take 
care not to short cycle the actuator. Unstable 
damper control can cause premature actuator fail-
ure.
Fast commissioning mode 
(modulating control mode and SYLK 
communication only)
When 24 VAC or 24 VDC signal is applied to the 
modulating input or on the SYLK communicating actuator 
the position 6 (TEST) is selected, the actuator will drive to 
the fully open position with higher speed corresponding to 
30 sec timing. When the signal is disconnected, the 
actuator will drive to the fully closed position with normal 
operation timing.
Do not use fast test mode for permanent 
operation.
Lifetime will be reduced if this mode is used 
permanently. This mode is intended to be used only 
for initial commissioning/testing of the system 
after installation. Power consumption is not 
specified in this mode.
Auxiliary Switches
Some models include Auxiliary switches. For wiring details 
see Fig. 11.
Actuator Override
To override the control signal (for freeze protection or 
similar applications):
1. Override to full open (fast commissioning, drive 
mode lower than 30 sec):
a. Disconnect the input signal (from terminal 3).
b. Apply 24 VAC to terminal 3.
c. See Fig. 19.
NOTES: When using two transformers in the installation, make sure you connect 
the corresponding legs of the secondary windings as Common. Check 
voltage as shown in the picture and make sure it is lower than 30 VAC. 
If not, swap the legs of one secondary winding. 
1
2
3
LINE VOLTAGE POWER SUPPLY. PROVIDE DISCONNECT MEANS 
AND OVERLOAD PROTECTION AS REQUIRED.
24 VDC SUPPLY ACCEPTABLE.
ADDRESS SELECTOR
24 VAC
CLASS 2
24 VAC
CLASS 2
24 VAC
CLASS 2
24 VAC
CLASS 2
24 VAC
CLASS 2
TO ACTUATOR HOT
TO CONTROLLER HOT
COMMON
< 30 VAC
TO ACTUATOR HOT
TO CONTROLLER HOT
COMMON
> 30 VAC
24 VAC
CLASS 2
S-BUS
S-BUS
RED
BLACK
BROWN
BROWN
ACTUATOR
ADDRESS 11
ADDRESS 12
ADDRESS 13
ADDRESS 14
ADDRESS 15
TEST
HOT
COM
CONTROLLER
S-BUS
S-BUS