Communicating Modulating Damper Actuator | RS-485 Interface

Product Selection Summary

Choose This Communicating Modulating Damper actuator When

Place this communicating damper actuator on the shortlist when a compatible rotary air damper requires proportional 2-10 V positioning and the project also needs an RS-485 field connection for supervisory integration. The controls design must define which commands remain hardwired, which information crosses the network and which interface has authority during normal, override and fault conditions.

• The required damper torque can be matched to a more-than-4, 5 or 10 Nm configuration.
• The selected 90-degree runtime of 3, 7 or 14 seconds suits the complete control sequence.
• AC/DC 24 V power, 2-10 V command and 2-10 V position feedback match the panel design.
• The damper has a 12-15 mm round or 10 x 10 mm square shaft and adequate mounting clearance.
• The project can obtain and approve the exact RS-485 protocol and point documentation before commissioning.

What Communication Adds

The RS-485 interface can reduce separate field wiring or expose actuator information to a controller when the supplied protocol supports the required points. It can also support centralized command, position monitoring, diagnostics or setup, depending on the approved interface documentation. These capabilities must be confirmed point by point; the presence of D+ and D- terminals alone does not prove a specific protocol or data set.

Do Not Select from the Network Label Alone

The actuator still has to move the damper under load. Check breakaway and running torque, shaft geometry, working angle, runtime, enclosure, environment and manual access before network design. A device that communicates correctly but cannot move the blade through the required range is not an acceptable damper actuator.

Also define analog and network command ownership. If both interfaces can write position, the sequence must identify priority, limits, override release and the state used after communication loss. Avoid parallel control paths that can issue conflicting demands or hide a failed analog loop behind a network value.

Information Required for a Project-Ready Quotation

Provide the damper tag, type and size, calculated torque, shaft details, required travel and runtime, AC/DC 24 V supply, analog command and feedback scaling, network protocol, controller or BMS, address and baud requirements, topology, termination, normal/override/fault sequence, environment, quantity and destination. Include the control schematic, network riser and point list when available.

The quotation should return the selected actuator variant, applicable electrical and mechanical data, supplied cable and accessories, exact protocol declaration, available points or registers, setup method, communication-loss behavior, mounting information and unresolved approval items.

Key Specifications and Variant Comparison

The three communicating actuator variants share one enclosure and interface family but pair different torque with different running time. Begin with the installation envelope and shaft checks below, then select the corresponding variant from the table. The values are separate configurations, not adjustable torque or speed settings on every unit.

Allow for the 121.7 x 69.2 x 71.5 mm body plus cable, network and service clearance, and match a 12-15 mm round or 10 x 10 mm square shaft. Check shaft projection, clamp engagement, bearing, insulation and anti-rotation restraint against the damper drawing. Keep the RJ and RS-485 setup and termination area accessible after installation, then select the torque/runtime row from verified damper load and system-response requirements.

Shared Mechanical and Environmental Data

Travel is mechanically adjustable from approximately 30 to 95 degrees, with clockwise or counter-clockwise direction selected by switch. The actuator provides push-button travel adaptation, mechanical position indication and a press-to-operate manual release. Weight is approximately 612 g, and the available cable reference is 800 mm with 5 x 0.75 mm2 conductors.

The operating environment is 0 to +50 degrees C and 10-95% relative humidity without condensation. Storage is -20 to +50 degrees C under the same humidity condition. Rated sound is a maximum of 52 dB, and position accuracy is better than +/-1% for the listed family.

Electrical Revision Check

The technical sheet lists 7 W running and 0.5 W holding, while the illustrated CQRB 3-second/4 Nm label shows 9 VA and 5 W. Your quotation and approved model sheet must identify the applicable supply and power values for the delivered revision. Do not size a shared transformer or circuit from a mixed family reference.

Analog Control, Position Feedback and RS-485 Wiring

The communicating actuator keeps a hardwired 2-10 V command and 2-10 V position-feedback path while adding an RS-485 interface. This architecture can support local analog control with network supervision, network command with analog monitoring, or another approved ownership arrangement. The controls narrative must select one arrangement and define priority rather than leaving both interfaces active without coordination.

Read the Wiring by Function

The IN terminal receives the 2-10 V position demand, T is the analog common and OUT returns a 2-10 V actuator-position signal. The separate power block supplies AC/DC 24 V. The RS-485 block provides D+, D- and a reference/common terminal. The RJ interface is shown with address 1 and baud rate 38400 as a setup reference.

Use the figure and connection schedule as one coordination reference. Final terminal names, polarity, common reference, shield treatment, network topology and setup values must match the supplied revision and the approved control design; the address and baud rate shown in the figure are setup references rather than universal project settings.

Position Feedback Is Not Process Feedback

The 2-10 V output can confirm that the actuator followed its command or reached an expected angular position. It cannot confirm airflow, face velocity, duct pressure or room pressure. A complete VAV or laboratory ventilation loop requires an appropriate process sensor and commissioning measurement.

Manual Override and Adaptation

The actuator provides a press-to-operate manual release, a direction switch and an adaptation button. Use manual override only under the approved maintenance procedure and with the controlled system in a safe state. After mechanical alignment, run adaptation so the actuator learns the installed start and end positions before validating analog and network commands.

RS-485 Network Integration and Protocol Approval

RS-485 Is the Transport Layer

RS-485 defines the electrical serial interface used by D+ and D-. It does not by itself identify the application protocol, object model, register map or command permissions. Before the actuator enters the BMS schedule, obtain a current protocol declaration for the exact supplied revision and verify that the supervisory controller supports it.

Documents Required Before Network Approval

The submittal should include the point or register map, address range, default and available baud rates, parity and stop-bit options, supported read/write functions, data types, scaling, units, command priority, status and fault points, write persistence, communication timeout and recovery behavior. It should also identify the physical setup method, firmware or hardware revision and any commissioning tool or password requirement.

Topology, Polarity and Termination

RS-485 networks normally require a controlled trunk topology rather than arbitrary star branches. Maintain D+/D- polarity, document the reference/common conductor, route the cable away from power noise and apply shield grounding according to the project standard. Termination and biasing must follow the approved network design and device manual; do not add a resistor value copied from another actuator brand.

Analog and Network Command Ownership

Define whether the analog input is the normal command, a fallback, a local override or a commissioning input. If the network can also command position, specify which source has priority, how an override is released and what value is retained after a restart. The BMS point list should distinguish commanded position, actual actuator position, communication status and any process measurement from a separate sensor.

Communication-Loss Sequence

The project must define the actuator’s required behavior when communication is lost but power and analog input remain available. Possible project strategies include following the hardwired demand, holding the last valid position or moving to a separately defined state, but only behavior supported by the supplied actuator may be selected. Test timeout detection, fallback, alarm generation and recovery during commissioning.

Direct-Coupled Mounting and Mechanical Fit

Shaft Interface

The communicating actuator fits a 12-15 mm round shaft or a 10 x 10 mm square shaft. Confirm the actual shaft profile, flats, usable engagement and surface condition rather than relying on nominal damper size. The technical sheet shows a maximum 50 mm shaft-projection reference; the approved installation drawing should establish the required engagement and finished position.

Enclosure and Access

The enclosure measures 121.7 x 69.2 x 71.5 mm. Allow additional space for the clamp, bearing projection, anti-rotation support, cable bend, RS-485 and analog wiring, RJ setup access, adaptation button and manual release. Coordinate the installed envelope with insulation, access panels and adjacent duct components.

Torque Verification

Use the damper manufacturer’s torque data or a documented measurement at the maximum operating and close-off pressure. Include breakaway friction, blade seals, bearings, linkage, contamination and the project-approved allowance. Select the corresponding 4, 5 or 10 Nm configuration only after this calculation; communication capability does not compensate for insufficient torque.

Rotation and Working Angle

Set the required 30-95 degree working range with the mechanical stops and match clockwise or counter-clockwise operation to the blade sequence. Place the damper and actuator at corresponding reference positions before tightening the clamp. Run adaptation after alignment, then verify that network and analog commands produce the same physical direction.

Installation Environment

The listed operating range is 0 to +50 degrees C and 10-95% relative humidity without condensation. For laboratory exhaust, determine whether corrosive vapor, washdown, condensation or outdoor exposure can reach the actuator. The product record does not establish a corrosion or ingress-protection rating, so harsh environments require an approved enclosure and installation review.

Applications and Project Fit

Laboratory Exhaust dampers

The communicating actuator can drive a compatible rotary exhaust damper where a laboratory controls system needs rapid proportional movement, hardwired position feedback and an RS-485 connection. The damper material and exposed components must still be reviewed against the airstream chemistry. A communicating actuator does not add corrosion resistance to the damper or enclosure.

Fume Hood Exhaust Branches

For a fume hood VAV branch, the actuator may position a suitable exhaust damper in response to a separate hood controller. Face velocity, airflow or sash demand must come from the approved control system, and containment must be verified with the correct sensor and test method. Actuator position and network status are useful diagnostics but are not face-velocity proof.

VAV Terminals and General HVAC Dampers

The product can serve compatible VAV terminal, supply, return and general exhaust dampers where the 4-10 Nm torque range, 3-14 second runtime, shaft interface and environmental limits fit. Network participation is valuable only when the controller can support the supplied protocol and the project point list uses the available data.

Use Another Architecture When

Use the Fast Modulating Damper actuator when analog control is sufficient and RS-485 adds no project value. Choose the future Modulating Damper actuator when standard-speed analog positioning fits, a Spring-Return Damper actuator when mechanical movement after power loss is required, or an external controller/actuator architecture when torque, protocol, fail behavior or control ownership must be selected independently.

Do not use this product as a fire/smoke actuator, certified isolation actuator, explosion-proof actuator, outdoor actuator or complete airflow controller unless the exact supplied assembly carries the required approval and function.

How to Select and Specify a Communicating Damper actuator

1. Define the Damper and Mechanical Load

Record the damper type, size, blade arrangement, design pressure, shaft profile, usable length, working angle and required direction. Calculate breakaway and running torque with the appropriate allowance. Select the 4, 5 or 10 Nm variant only after the mechanical requirement is established.

2. Select the Runtime

Match the 3, 7 or 14-second 90-degree runtime to the complete control sequence. Include sensor dynamics, controller tuning, damper authority, duct pressure and fan response. The actuator runtime is one component of system response, not a guarantee of airflow or room-pressure settling time.

3. Define Analog Signals

Specify the 2-10 V command and 2-10 V position-feedback scaling, common reference, input/output ownership and signal-loss behavior. State which voltage represents the installed closed and open positions. Position feedback must be named as actuator position rather than airflow feedback.

4. Approve the Communication Interface

State the required protocol, network controller, address, baud rate, parity, topology, termination, point or register list, command permissions and communication-loss state. Require the exact XICHENG protocol document before final approval. Do not write only “RS-485 compatible” in a specification that expects a defined BMS integration.

5. Resolve Command Priority and Failure States

Define normal analog and network ownership, local override, emergency demand, startup position, power-loss position, signal-loss state, communication timeout, recovery and alarm behavior. If mechanical fail-safe movement is required, select an actuator with a verified return mechanism.

6. Confirm Mounting and Environment

Check the 121.7 x 69.2 x 71.5 mm enclosure, shaft interface, clamp engagement, service clearance, cable routing, temperature, humidity and exposure. Make sure the setup interface remains accessible after installation and that network wiring can follow the approved topology.

Suggested Tag Schedule

List the actuator product type, exact configuration, torque, runtime, working angle, direction, supply and power, analog command, position feedback, RS-485 protocol and setup, network points, topology and termination, shaft and mounting, normal/override/failure behavior, environment, supplied accessories and required approval documents. The quotation and approved submittal define the delivered revision.

Installation and Commissioning

Pre-Installation Review

• Verify the configuration, torque, runtime, power revision and protocol documentation against the approved schedule.
• Move the damper manually and correct binding, excessive seal friction or shaft misalignment.
• Confirm shaft profile, engagement, enclosure clearance and access to manual/setup controls.
• Review the analog wiring diagram, network riser, addressing plan, cable and termination schedule.
• Isolate power and follow the project lockout procedure.

Mechanical Installation and Adaptation

Align the actuator and damper at corresponding reference positions, engage the shaft clamp, secure the anti-rotation arrangement and set the required working angle. Do not force the damper beyond its mechanical stops. Restore power and run the adaptation procedure so the actuator learns the installed endpoints.

Analog Point-to-Point Test

Apply minimum, intermediate and maximum 2-10 V commands and verify physical rotation, direction and 2-10 V position feedback. Confirm the controller and BMS use the correct scaling and common reference. Test loss of analog command according to the approved sequence.

RS-485 Commissioning

Set or verify the approved address, baud and other serial parameters. Check D+/D- polarity, reference conductor, shield treatment, trunk topology and termination. Confirm that the network controller can identify the actuator and read only the points documented for the supplied protocol. Then test authorized writes, overrides, timeout and recovery.

System Functional Test

Operate the completed ventilation system through minimum, normal, maximum, emergency and failure states. Verify command priority, actuator position, measured airflow or pressure from the separate process sensor, alarms and fan coordination. Record any difference between commanded position and delivered process performance for balancing or controls correction.

Handover Records

Retain the model and revision, protocol document, point/register map, network settings, actuator tag, shaft and mounting data, analog scaling, configured travel, measured runtime, failure tests and unresolved items. The final records should allow a future technician to distinguish actuator position, network status and process measurement.

Related Damper actuator and Control Options

Fast Modulating Damper actuator

Select this analog-only family when 2-15 second rapid modulation is required but the actuator does not need direct RS-485 network participation. It provides a broader fast torque/runtime range without implying a communication protocol.

Modulating Damper actuator

Evaluate the standard-speed product when proportional analog positioning is required and a 30-second-or-slower runtime suits the application. It should own conventional modulating demand rather than duplicate the communicating page.

Spring-Return Damper actuator

Choose a verified spring-return unit when loss of power must mechanically move the damper to a defined position. Confirm return direction, torque, return time and approval requirements.

VAV Airflow and Pressure Controller

Use a controller page when the product must measure airflow or pressure, execute closed-loop control and coordinate a damper actuator. The communicating actuator on this page positions the shaft but does not provide process sensing.

Frequently Asked Questions

What is a communicating modulating damper actuator?

It is a motorized air-damper actuator that combines shaft positioning with a field communication interface. This XICHENG family uses a 2-10 V command, 2-10 V position feedback and RS-485 terminals in a direct-coupled rotary enclosure.

Does RS-485 mean the actuator supports Modbus or BACnet?

No. RS-485 defines the electrical serial interface. Modbus RTU, BACnet MS/TP or another protocol requires a separate declaration and point/register document for the exact actuator revision. Do not infer the protocol from D+ and D- terminals alone.

Which torque and runtime variants are available?

The verified family pairs more than 4 Nm with 3 seconds, more than 5 Nm with 7 seconds, and more than 10 Nm with 14 seconds per 90-degree travel. Select from verified damper torque and system response, not speed alone.

Can analog and network commands be used together?

They may participate in one approved sequence if the supplied protocol supports the required command and the controls design defines ownership, priority, override and fallback. Two uncontrolled command sources should not write the same actuator position.

Does the 2-10 V output report airflow?

No. It reports actuator position. Airflow, face velocity and pressure require separate sensors and acceptance measurements.

What must be confirmed for RS-485 commissioning?

Confirm the protocol, point or register map, address range, baud rate, parity, stop bits, topology, D+/D- polarity, reference conductor, shielding, termination, write permissions, timeout and communication-loss behavior. The diagram shows address 1 and baud 38400 as a reference, not a complete network manual.

Is this a spring-return or fail-safe actuator?

The available product record does not establish a universal mechanical spring-return function. Define the required power-loss position and choose a verified spring-return actuator when mechanical return is mandatory.

What information is required for quotation?

Provide damper and torque data, shaft dimensions, required runtime, AC/DC 24 V supply, analog scaling, protocol and point requirements, network settings, topology, termination, normal and failure sequence, environment, drawings, quantity and destination.