The Belimo TFCX120-S is a compact spring-return (fail-safe) damper actuator delivering 22 in-lb [2.5 Nm] of torque with on/off (two-position) control on AC 100-240 V power. As Belimo's smallest spring-return class, it direct-couples to round damper shafts from 1/4 in. to 1/2 in. and, on loss of power, its internal spring returns the damper to a fail-safe position in under 25 seconds, making it part of Belimo's configurable TFX platform for small commercial HVAC dampers that must fail safe. Its 30-second motor drives the damper faster than the standard 75-second TF. A built-in SPDT auxiliary switch signals damper position or interlocks equipment.
Specifications sourced from the official Belimo TFCX120-S technical data sheet (rev 2023-08-11).
Overview
Belimo TF-Series actuators are Belimo's smallest spring-return drives, sized for small commercial HVAC control dampers that require fail-safe operation. The TFCX120-S produces 22 in-lb [2.5 Nm] and mounts directly to round damper shafts from 1/4 in. to 1/2 in. with its universal clamp. On power loss the spring returns the damper to its fail-safe position in under 25 seconds; the fail-safe direction is reversible by CW/CCW mounting. This TFC model uses a faster 30-second motor (versus 75 seconds on the standard TF). Two-position on/off control drives the damper, and the spring returns it on signal or power loss.
Best for
- Small commercial HVAC dampers needing fail-safe (spring-return) operation
- Compact zone, VAV and terminal-unit damper control (22 in-lb)
- Outdoor-air and exhaust dampers that must fail safe
- Faster (30-second) damper actuation
- End-position signaling or interlock (1x SPDT)
- Line-voltage systems (AC 100-240 V)
Key Features
Spring-Return Fail-Safe
A mechanical spring drives the damper to a safe position on power or signal loss (under 25 seconds) — no external power needed to fail safe.
Smallest 22 in-lb Class
Belimo's most compact spring-return actuator; direct-couples to round damper shafts from 1/4 in. to 1/2 in. for small dampers.
On/Off Control
Accepts two-position on/off control from a controller, relay or switch.
Reversible Fail-Safe Direction
The spring-return (fail-safe) direction is selectable clockwise or counterclockwise by mounting orientation.
Faster 30-Second Motor
Drives 90° in about 30 seconds — quicker damper response than the standard 75-second TF actuator.
Built-In SPDT Aux Switch
One SPDT auxiliary switch (1 mA-3 A) signals damper end position or interlocks other equipment.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Belimo |
| Part Number | TFCX120-S |
| Actuator Type | Spring-Return (Fail-Safe) Damper Actuator |
| Nominal Voltage | AC 100-240 V |
| Nominal Frequency | 50/60 Hz |
| Power Consumption (Running) | 3 W |
| Torque (Motor & Spring) | 22 in-lb [2.5 Nm] (minimum) |
| Control Signal | On/Off (two-position) |
| Shaft Range | 1/4 in. to 1/2 in. [6.4-12.7 mm] via universal clamp (1/2 in. self-centering) |
| Angle of Rotation | 95° (adjustable mechanical stops) |
| Running Time (Motor) | 30 s (fast) |
| Spring Return Time | < 25 s (< 60 s below -22°F) for fail-safe |
| Behavior on Power Loss | Spring returns damper to fail-safe position |
| Fail-Safe Direction | Reversible (CW/CCW) by mounting orientation |
| Auxiliary Switch | 1x SPDT, 1 mA-3 A (0.5 A inductive), DC 5 V-AC 250 V |
| Electrical Connection | 18 GA appliance 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 | 1.6 lb [0.71 kg] |
| Warranty | 5 Years |
Documentation
Related Products
Accessories & Mounting
Common Belimo accessories for mounting, linkage, signaling and powering the TFCX120-S, drawn from the TF actuator datasheet. All are stocked by ZOT Supply as an authorized Belimo distributor.
Mounting & Linkage
Electrical Add-Ons
Frequently Asked Questions
What is the Belimo TFCX120-S?
The Belimo TFCX120-S is Belimo's smallest spring-return (fail-safe) damper actuator, for small commercial HVAC dampers. It produces 22 in-lb [2.5 Nm] of torque, uses on/off (two-position) control on AC 100-240 V power, and on power loss its spring drives the damper to a fail-safe position in under 25 seconds.
Is the TFCX120-S a spring-return (fail-safe) actuator?
Yes. A mechanical spring drives the damper to its fail-safe position when power or the control signal is lost — no external power is needed to fail safe.
How much torque does the TFCX120-S provide?
It delivers 22 in-lb [2.5 Nm] of torque. TF is Belimo's smallest spring-return class, sized for compact zone, VAV and terminal-unit dampers.
What shaft sizes does the TFCX120-S fit?
It direct-couples to round damper shafts from 1/4 in. to 1/2 in. using its universal clamp, self-centering at 1/2 in. A crank arm (KH-TF US) and brackets are available for off-shaft mounting.
What control signal does the TFCX120-S use?
It uses on/off (two-position) control. Two-position on/off control is driven from a controller, relay or switch.
What is the difference between the TFC and TF actuators?
The TFC uses a faster motor — about a 30-second running time for 90 degrees, versus 75 seconds on the standard TF. Both are 22 in-lb spring-return actuators.
Does the TFCX120-S have an auxiliary switch?
Yes. It has one SPDT auxiliary switch (rated 1 mA to 3 A at up to 250 V) for end-position signaling or interlocking other equipment.
What voltage does the TFCX120-S run on?
The TFCX120-S is a line-voltage actuator running on AC 100-240 V, so no separate 24 V control transformer is required.
Does the TFCX120-S have a manual override?
No. Like other compact spring-return actuators, the TFCX120-S has no manual override — the spring sets the fail-safe position and the motor drives the powered direction.
Is the Belimo TFCX120-S available from an authorized Belimo distributor?
Yes. ZOT Supply is an authorized Belimo distributor and carries the TFCX120-S. Every unit ships factory new with Belimo's full 5-year warranty and application support.
- Actuator Type:
- Spring-Return (Fail-Safe)
- Torque:
- 22 in-lb
- Control Signal:
- On/Off
- Voltage:
- Line Voltage (100-240 VAC)
- Auxiliary Switch:
- 1x SPDT
- Series:
- TFCX
- Running Time:
- Fast (30 s)
