INSTALLATION INSTRUCTIONS
31-00141M-06
https:// en-US/Pages/department.aspx?cat=HonECC%20Catalog&category=Commercial&catpath=1.1
3 Nm Series Spring Return 
Direct Coupled Actuators
MS7103, MS7503, MS3103
MS7103, MS7503, MS3103 Spring Return Direct Coupled 
Actuators (DCA) are used within heating, ventilating, and 
air-conditioning (HVAC) systems. They can drive a variety of 
quarter-turn, final control elements requiring spring return 
fail-safe operation.
Applications include:
• 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
SPECIFICATIONS
Models:
 See Table 1.
Device Weight:
 1.7lbs (0.78 kg)
Ambient Operating Temperature:
 -40° to 150°F (-40° to 65°C)
Shipping and Storage Temperature:
 -40° to +150°F (-40° to +65°C)
1
 2-10 VDC
2
 0(2)-10 VDC, 10-0(2) VDC
Table 1. Models.
Model Number
Control Input / 
Output 
Description
SPST 
Aux 
Switches
1/2” 
360° 
Conduit
Shaft 
Adapter Torque Supply Voltage
Driving/ 
Holding 
(VA)
Drive 
(sec)
MS7103A1021
Modulating
1
No
Yes
SCSA
27 lb-in 
(3 N)
24 VAC +/-20% @ 
50/60 Hz Class 2 
Transformer, 24 VDC 
+20%/-10%
4/2 90
MS7103A2021
Modulating
1
, 
Feedback
4/2 90
MS7103A2221 Yes 4/2 90
MS7503A2021
Modulating
2
, 
Floating, 2 Pos, 
Feedback
No 4/2 90
MS7503A2221 Yes 4/2 90
MS7503A2023 No
U-Bolt
4/2 90
MS7503A2223 Yes 4/2 90
MS7103A2024
Modulating
1
, 
Feedback
No
No
4/2 90
MS7103A2224 Yes 4/2 90
MS3103J1023
Sylk BUS
No
Yes 4.5/2 30-180
MS3103J1024 No 4.5/2 30-180
MS3103J1221
Yes
Yes
SCSA
4.5/2 30-180
MS3103J1222 No 4.5/2 30-180
MS3103J1223 Yes
U-Bolt
4.5/2 30-180
MS3103J1224 No 4.5/2 30-180
MS3103J1021
No
Yes
SCSA
4.5/2 30-180
MS3103J1022 No 4.5/2 30-180