The Belimo AMX120-SR is a non-spring-return damper actuator delivering 180 in-lb [20 Nm] of torque with modulating 2-10 VDC control on AC 100-240 V power. It direct-couples to damper shafts up to 1.05 in. diameter and holds its last position on loss of power (it is non-fail-safe, with no spring return), making it part of Belimo's configurable AMX platform for commercial HVAC damper control where fail-safe operation is not required.
Specifications sourced from the official Belimo AMX120-SR technical data sheet (rev 2025-10-06).
Overview
Belimo AM-Series actuators are non-spring-return drives for commercial HVAC dampers — they position the damper under power and hold the last commanded position when power is removed (there is no spring-return fail-safe). The AMX120-SR produces 180 in-lb [20 Nm] of torque and mounts directly to the damper shaft. A 2-10 VDC (or 4-20 mA with the ZG-R01 resistor) signal modulates the damper, with 2-10 VDC position feedback.
Best for
- VAV and modulating damper control without fail-safe return
- Non-spring-return damper and louver positioning (180 in-lb)
- Direct shaft mount up to 1.05 in. diameter
- Line-voltage systems (AC 100-240 V)
Key Features
Non-Spring-Return Design
Holds the last commanded position when power is removed (non-fail-safe). Lower cost and power draw than a spring-return actuator where fail-safe operation is not required.
180 in-lb Torque
Direct-couples to damper shafts up to 1.05 in. diameter and sizes a wide range of commercial dampers and louvers.
Modulating 2-10 VDC
Accepts a 2-10 VDC (or 4-20 mA with ZG-R01) signal with 2-10 VDC position feedback for precise modulation.
Line-Voltage Power
Runs directly on AC 100-240 V line power — no separate 24 V transformer required.
cULus Listed & Quiet
Double-insulated (Class 2), cULus listed, ISO 9001 built, and UL 2043 plenum-rated for long, maintenance-free service.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Belimo |
| Part Number | AMX120-SR |
| Actuator Type | Non-Spring-Return (Non Fail-Safe) Damper Actuator |
| Nominal Voltage | AC 100-240 V |
| Nominal Frequency | 50/60 Hz |
| Power Consumption (Running) | 4 W |
| Transformer Sizing | 7.5 VA |
| Torque | 180 in-lb [20 Nm] |
| Control Signal | Modulating |
| Operating Range (Y) | 2-10 VDC (4-20 mA with ZG-R01 resistor) |
| Position Feedback (U) | 2-10 VDC (max. 0.5 mA) |
| Angle of Rotation | Max. 95° (adjustable mechanical stop) |
| Running Time (Motor) | 90 s / 90° Running time motor note constant, independent of load |
| Behavior on Power Loss | Holds last position (non-spring-return) |
| Manual Override | Self-locking; declutch / hand crank per model |
| Direction of Motion | Selectable (CW/CCW) |
| Electrical Connection | 18 AWG plenum cable, 3 ft [1 m], 1/2" NPT conduit connector |
| Overload Protection | Electronic, full 0-95° rotation |
| Electrical Protection | Double insulated (Class 2) |
| Enclosure Rating | NEMA 2 / UL Type 2 |
| Ambient Temperature | -22 to 122°F [-30 to 50°C] |
| Agency Listing | cULus (UL60730-1A / -2-14, CAN/CSA) |
| Quality Standard | ISO 9001 |
| Plenum Rated | UL 2043 (suitable for air plenums) |
| Weight | 2.3 lb [1.1 kg] |
| Warranty | 5 Years |
Documentation
Related Products
Accessories & Mounting
Common Belimo accessories for mounting, signaling and protecting the AMX120-SR, drawn from the actuator datasheet. All are stocked by ZOT Supply as an authorized Belimo distributor.
Mounting & Shaft
Electrical Add-Ons
Enclosures & Weather Shields
Frequently Asked Questions
What is the Belimo AMX120-SR?
The Belimo AMX120-SR is a non-spring-return (non-fail-safe) damper actuator for commercial HVAC. It produces 180 in-lb [20 Nm] of torque, uses modulating 2-10 VDC control on AC 100-240 V power, and holds its last position on loss of power. Its housing is rated NEMA 2.
Is the AMX120-SR a spring-return (fail-safe) actuator?
No. The AMX120-SR is non-spring-return: when power is lost it holds its last commanded position rather than driving to a fail-safe position. If you need the damper to fail to a known open or closed position on power loss, choose a spring-return Belimo AF/AM-Series actuator instead.
What happens to the AMX120-SR when power is lost?
It stays put. A non-spring-return actuator maintains its last position when power is removed and resumes from there when power returns — there is no spring to drive it to a fail-safe position.
What torque does the AMX120-SR provide and what shaft sizes does it fit?
It delivers 180 in-lb [20 Nm] and direct-couples to round or square damper shafts up to 1.05 in. diameter using its universal clamp.
What control signal does the AMX120-SR use?
It uses modulating 2-10 VDC control. The 2-10 VDC input also accepts 4-20 mA with the ZG-R01 resistor and provides 2-10 VDC position feedback.
What is the running time of the AMX120-SR?
Motor running time is about 90 s / 90° Running time motor note constant, independent of load for 90 degrees of travel.
What voltage does the AMX120-SR run on?
The AMX120-SR is a line-voltage actuator: it runs on AC 100-240 V, so no separate 24 V control transformer is required.
Is the Belimo AMX120-SR available from an authorized Belimo distributor?
Yes. ZOT Supply is an authorized Belimo distributor and carries the AMX120-SR. Every unit ships factory new with Belimo's full 5-year warranty and application support from our team.
- Actuator Type:
- Non-Fail-Safe
- Torque:
- 180 in-lb
- Control Signal:
- Modulating
- Voltage:
- Line Voltage (100-240 VAC)
- Auxiliary Switch:
- No
- Enclosure:
- NEMA 2
- Series:
- AM
- Feedback Signal:
- 2-10 VDC
