Invensys NSR MF4E-60430 24V Floating Damper/Valve Actuator for BAS HVAC Control

Condition: Used; rust present on the output shaft (may need cleaning). Cosmetic wear from prior service expected. No brackets, linkages, or wiring harnesses included — actuator only.

Product Description

The Invensys NSR MF4E-60430 is a 24V “floating” (tri-state) HVAC actuator used in building automation systems to position dampers or valves based on OPEN / STOP / CLOSE commands from a controller. Floating control is popular in commercial HVAC because it’s simple, robust, and integrates easily with many BAS/DDC controllers that provide tri-state outputs.

This actuator is typically installed on airside equipment (VAV boxes, AHU dampers, economizers) or on hydronic valve linkages where a floating signal is used. The noted rust on the shaft may affect clamping/coupling and should be cleaned before installation so the hub grips properly and the actuator can be removed/serviced later.

Specifications

• Manufacturer/Brand: Invensys (NSR series)
• Model: MF4E-60430
• Control type: Floating / Tri-state (Open–Stop–Close)
• Power: 24V (commonly 24 VAC in HVAC controls)
• Typical use: Damper or valve actuation in commercial HVAC/BAS

If you share a photo of the nameplate (or the terminal label), I can add the exact wiring designations, torque, timing, and rotation angle.

Features

• Floating (tri-state) control for reliable OPEN/HOLD/CLOSE positioning
• 24V low-voltage actuation suited to BAS/DDC control panels
• Commonly used for damper positioning (economizer, mixing, zone control) and valve control (with linkage)
• Designed for commercial HVAC duty cycles (frequent repositioning)
• Service-friendly form factor typical of NSR actuator families

Applications

• Air Handling Units (AHUs): outside air/return air/mixed-air dampers, economizer dampers
• VAV/zone control: terminal box dampers, bypass dampers
• Exhaust/relief systems: relief dampers, building pressurization dampers
• Hydronic systems: floating-controlled valve actuation (with correct linkage/valve kit)
• General BAS retrofits: replacing older floating actuators on dampers

Spheres of Application

• Commercial office buildings and retail
• Schools/campuses and municipal facilities
• Light industrial HVAC and warehouses
• Property management maintenance and retrofit projects

Condition Notes and Service Tips

• Rust on shaft:
  • Clean with a non-aggressive method (e.g., light Scotch-Brite or fine abrasive) to restore smooth, round contact for the clamp hub.
  • After cleaning, wipe and protect with a light corrosion inhibitor (avoid contaminating friction surfaces if a clamp relies on dry grip).
• Confirm the damper shaft size and ensure the actuator hub clamps evenly—rust can cause slip, misalignment, or difficulty tightening.

Cross-Referenced Models

(These are family/functional cross-references—verify torque, runtime, stroke angle, and mounting before substituting.)

• Invensys / NSR MF4E series floating actuators (same product family; different torque/timing variants)
• Invensys MF4E-xxxxx variants used for 24V floating control (exact suffix differs by rating/config)

Comparable Products

(Comparable floating/tri-state actuators often used in BAS HVAC—confirm torque and timing match your application.)

• Belimo floating-control actuators (TF/AF/NF floating variants)
• Honeywell MS-series floating actuators (model varies by torque)
• Johnson Controls M9xx floating actuators
• Siemens OpenAir floating actuators (GMA/GCA classes, application-dependent)
• Schneider Electric (legacy TAC/Invensys lines) floating actuators of similar torque class

Use in Larger Systems

This actuator is commonly one piece of a BAS-controlled assembly:

• DDC controller tri-state output → actuator (OPEN/CLOSE commands) → damper shaft (or valve linkage)
• Often paired with:
  • Damper hardware: crank arm, anti-rotation bracket, shaft adapter
  • Sensors: discharge air temp, mixed air temp, CO₂, static pressure (depending on sequence)
  • End-switches / interlocks: fan enable, minimum position proving (sequence-dependent)

Related

Invensys floating actuator, NSR damper motor, tri-state 24V actuator, open stop close HVAC actuator, economizer damper actuator, VAV damper actuator, building automation actuator, damper position motor, valve actuator floating control, device to position HVAC dampers

Common Requests:

1. “Invensys MF4E-60430 24V floating actuator wiring OPEN CLOSE COMMON”
2. “Replacement for NSR MF4E floating damper actuator—matching torque and runtime”
3. “How to clean rusted actuator shaft and prevent hub slippage”
4. “Tri-state floating actuator for economizer/mixed air dampers (24V)”
5. “BAS controller OPEN/CLOSE output compatible actuator for VAV damper”

Trademarks Disclaimer

Invensys and any other manufacturer names mentioned are trademarks of their respective owners. References are used only for identification and comparison/compatibility purposes; no affiliation or endorsement is implied.

P125; B006; GT00107