Belimo NMB24-SR Damper Actuator 90 In-lb 24V Modulating

Product Description

The BELIMO NMB24-SR is a non-spring return damper actuator rated at 90 in-lb of torque, designed for modulating control of HVAC dampers in commercial and residential air handling systems. It operates on 24 VAC or 24 VDC power, draws 5 VA at nominal supply voltage, and accepts an analog control signal for precise positioning across the full damper stroke. The actuator carries an IP54 and NEMA 2 enclosure rating, making it suitable for installations where limited moisture exposure is a concern. Licensed HVAC technicians and building automation contractors are the primary installers of this type of device.

The NMB24-SR is applied in VAV systems, air handling units, makeup air units, and other ductwork assemblies where modulating damper control is required. Its analog input allows integration with DDC controllers, building automation systems, and standalone modulating thermostats. The non-spring return design means the actuator holds its last commanded position on power loss rather than driving to a fail-safe position, which is a deliberate design choice for certain control strategies.

Key Features

• 90 in-lb torque output suits a wide range of commercial damper sizes
• Non-spring return design holds last position on power loss
• Accepts analog control signal for full modulating positioning
• Operates on 24 VAC or 24 VDC power supply
• NEMA 2 and IP54 enclosure rating for limited moisture resistance
• Low 5 VA power draw reduces transformer loading

Compatibility

Designed as an OEM-style replacement or new-installation actuator for HVAC damper assemblies requiring a non-spring return, modulating, 24V actuator with 90 in-lb of torque output.

Installation Notes

Installation should be performed by a licensed HVAC technician or controls contractor familiar with low-voltage wiring and building automation systems. De-energize the control panel and disconnect power to the actuator circuit before any wiring or mounting work. Verify that the damper shaft size and actuator mounting bracket are compatible before securing the unit. Control wiring should comply with applicable local codes and the NEC for low-voltage signal wiring.

Technical Specifications

• Torque: 90 in-lb
• Power Supply: 24 VAC, 24 VDC
• Nominal Supply Voltage: 24 VAC
• Power Consumption: 5 VA
• Control Signal: Analog (modulating)
• Enclosure Rating: NEMA 2, IP54
• Spring Return: No (non-spring return)

Standard Information

• Brand: BELIMO
• Manufacturer Part Number: NMB24-SR