MS7103, MS7503 Spring Return Direct Coupled Actuators
(DCA) are used within heating, ventilating, and air-condi-
tioning (HVAC) systems. They can drive a variety of quarter-
turn, final control elements requiring spring return fail-safe
See Table 1.
1.7lbs (0.78 kg)
Control Input /
MS7103A1021 Modulating (1)
MS7103A2021 Modulating (1),
MS7103A2221 Modulating (1),
MS7503A2021 Modulating (2),
0(2)-10 VDC, 10-0(2) VDC
5% to 95% R.H., Non-Condensing
Auxiliary Switches (Two SPST):
Fixed switches on 10 and 80 degrees
125 VAC, 1A, res. load
3 Nm Series Spring Return
Direct Coupled Actuators
Table 1. Models.
• Volume control dampers, mounted directly to the drive
shaft or remotely (with the use of accessory hardware).
• Quarter-turn rotary valves, such as ball valves mounted
directly to the drive shaft.
• Available with cable on all models
• Fast test mode
Ambient Operating Temperature:
-40° to 150°F (-40° to 65°C)
Shipping and Storage Temperature:
-40° to +150°F (-40° to +65°C)
24 VAC +/-20% @
50/60 Hz class 2
24 VDC +20%/-10%
Mounting: Self-centering shaft adapter (shaft cou-
Round damper shafts: 3/8 to 5/8 in. (9 to 16 mm)
Square damper shafts: 1/4 to 1/2 in. (6 to 13 mm)
Nominal tightening torque for self-centering shaft
adapter screw is 106 lb-in (12Nm).