Product Introduction
I. Product Overview
This intelligent fresh air unit frequency conversion control box is a high-precision driving and control core specially designed for modern building automation systems (BAS) and intelligent building systems. Integrating advanced frequency conversion speed regulation technology, industrial-grade control interfaces, and rich status management functions, the product aims to achieve efficient, stable, and intelligent regulation of fans in fresh air units. By precisely controlling the fan speed, it not only meets dynamic air volume requirements and improves environmental comfort but also achieves significant energy-saving effects. It is an ideal choice for projects such as green buildings, clean workshops, and intelligent office buildings.
This intelligent fresh air unit frequency conversion control box is a high-precision driving and control core specially designed for modern building automation systems (BAS) and intelligent building systems. Integrating advanced frequency conversion speed regulation technology, industrial-grade control interfaces, and rich status management functions, the product aims to achieve efficient, stable, and intelligent regulation of fans in fresh air units. By precisely controlling the fan speed, it not only meets dynamic air volume requirements and improves environmental comfort but also achieves significant energy-saving effects. It is an ideal choice for projects such as green buildings, clean workshops, and intelligent office buildings.
II. Core Functional Features
1. Intelligent Central Control Core
Flexible controller interfaces: The box is pre-equipped with standard installation interfaces and terminal blocks for PLC (Programmable Logic Controller) or DDC (Direct Digital Controller). Users can freely select or integrate built-in control modules according to project complexity and control strategies to realize highly customized automatic control logic, such as advanced functions like temperature and humidity compensation, enthalpy value switching, schedule start-stop, and linkage control.
1. Intelligent Central Control Core
Flexible controller interfaces: The box is pre-equipped with standard installation interfaces and terminal blocks for PLC (Programmable Logic Controller) or DDC (Direct Digital Controller). Users can freely select or integrate built-in control modules according to project complexity and control strategies to realize highly customized automatic control logic, such as advanced functions like temperature and humidity compensation, enthalpy value switching, schedule start-stop, and linkage control.
2. Comprehensive Status Feedback and Monitoring
Hand/Auto Feedback: Real-time upload of the current control mode (manual or automatic) to the monitoring system, ensuring that the central dispatch center clearly grasps the local authority status of the equipment to prevent misoperation.
Run Feedback: Passive dry contact signal output, accurately indicating whether the fan is in operation or stopped, for central status monitoring and logical interlocking.
Fault Feedback: When the control box detects abnormalities such as overload, short circuit, phase loss, or frequency converter failure, it immediately sends a passive dry contact alarm signal and uploads it to the monitoring center, enabling predictive maintenance and facilitating engineers to quickly locate and eliminate faults.
Hand/Auto Feedback: Real-time upload of the current control mode (manual or automatic) to the monitoring system, ensuring that the central dispatch center clearly grasps the local authority status of the equipment to prevent misoperation.
Run Feedback: Passive dry contact signal output, accurately indicating whether the fan is in operation or stopped, for central status monitoring and logical interlocking.
Fault Feedback: When the control box detects abnormalities such as overload, short circuit, phase loss, or frequency converter failure, it immediately sends a passive dry contact alarm signal and uploads it to the monitoring center, enabling predictive maintenance and facilitating engineers to quickly locate and eliminate faults.
3. High-Precision Frequency Conversion Regulation and Monitoring
Frequency Given: Supports analog signals (0-10V or 4-20mA) to receive control commands from PLC/DDC or environmental sensors, realizing "stepless linear regulation" of the fan operating frequency and controlling smooth changes in air volume.
Frequency Feedback: Real-time feedback of the current output frequency of the frequency converter to the upper monitoring system in the form of "analog signals (0-10V or 4-20mA)" to form closed-loop monitoring. Operators can accurately grasp the real-time speed of the fan, verify the correct execution of control commands, and avoid "blind adjustment".
Frequency Given: Supports analog signals (0-10V or 4-20mA) to receive control commands from PLC/DDC or environmental sensors, realizing "stepless linear regulation" of the fan operating frequency and controlling smooth changes in air volume.
Frequency Feedback: Real-time feedback of the current output frequency of the frequency converter to the upper monitoring system in the form of "analog signals (0-10V or 4-20mA)" to form closed-loop monitoring. Operators can accurately grasp the real-time speed of the fan, verify the correct execution of control commands, and avoid "blind adjustment".
4. Powerful System Integration and Communication Capabilities
Standard RS485 communication interface: Built-in RS485 physical interface, supporting the open "MODBUS-RTU communication protocol".
Transparent data interaction: Through this interface, the control box can act as a slave device, easily accessing building automation systems, energy management systems, or intelligent operation and maintenance platforms. It can not only upload all operating data such as status, current, and frequency but also receive control commands such as "start-stop and frequency setting" from the master station, achieving perfect integrated control and centralized management.
Standard RS485 communication interface: Built-in RS485 physical interface, supporting the open "MODBUS-RTU communication protocol".
Transparent data interaction: Through this interface, the control box can act as a slave device, easily accessing building automation systems, energy management systems, or intelligent operation and maintenance platforms. It can not only upload all operating data such as status, current, and frequency but also receive control commands such as "start-stop and frequency setting" from the master station, achieving perfect integrated control and centralized management.
5. Complete Protection and Reliability Design
Electrical protection: Equipped with circuit breakers, AC contactors, and thermal overload relays (or frequency converter built-in protection), providing comprehensive protection against short circuits, overcurrent, phase loss, and overload to ensure the safety of the fan motor and control system.
Frequency converter protection: The core frequency conversion drive unit has comprehensive protection functions such as motor locked-rotor, overvoltage, undervoltage, and overheating protection.
Emergency manual function: The control box door panel is equipped with a "manual/automatic" changeover switch, emergency stop button, manual start-stop buttons, and indicator lights, ensuring that the equipment can be operated safely and conveniently locally during debugging, maintenance, or system failure.
Electrical protection: Equipped with circuit breakers, AC contactors, and thermal overload relays (or frequency converter built-in protection), providing comprehensive protection against short circuits, overcurrent, phase loss, and overload to ensure the safety of the fan motor and control system.
Frequency converter protection: The core frequency conversion drive unit has comprehensive protection functions such as motor locked-rotor, overvoltage, undervoltage, and overheating protection.
Emergency manual function: The control box door panel is equipped with a "manual/automatic" changeover switch, emergency stop button, manual start-stop buttons, and indicator lights, ensuring that the equipment can be operated safely and conveniently locally during debugging, maintenance, or system failure.
III. Typical Application Scenarios
* Fresh air units in intelligent office buildings
* Clean air conditioning systems in hospital operating rooms and laboratories
* Ventilation systems in public areas of hotels and shopping malls
* Environmental ventilation and exhaust systems in factory workshops
* Any occasion requiring precise on-demand adjustment of air volume
* Fresh air units in intelligent office buildings
* Clean air conditioning systems in hospital operating rooms and laboratories
* Ventilation systems in public areas of hotels and shopping malls
* Environmental ventilation and exhaust systems in factory workshops
* Any occasion requiring precise on-demand adjustment of air volume
IV. Technical Parameters
| Item | Parameter/Description |
| Rated voltage | AC 380V ±15%, 50/60Hz (220V specification optional) |
| Controlled motor power | 0.75kW ~ 45kW (covering the power range of common fresh air units) |
| Control mode | Variable frequency speed regulation (VFD) |
| Frequency control | 0 - 50Hz (or 0 - 60Hz) stepless adjustable |
| Given/feedback signal | Analog quantity: 0-10V DC or 4-20mA (jumper optional) |
| Communication interface | RS485 |
| Communication protocol | MODBUS-RTU |
| Status feedback | Passive dry contact (normally open/normally closed optional) |
| Protection level | IP20 (cabinet) or higher (customizable upon request) |
| Installation method | Wall-mounted / floor-standing |
V. Selection and Ordering Instructions
To ensure the product perfectly matches your project requirements, please provide the following information when selecting or ordering:
1. Fan motor power, rated current, and voltage.
2. Desired control logic (whether a built-in PLC/DDC is required).
3. Signal type from sensors and control systems (0-10V or 4-20mA).
4. Whether there are special communication protocol or function customization requirements.
5. Requirements for cabinet material, color, and protection level.
To ensure the product perfectly matches your project requirements, please provide the following information when selecting or ordering:
1. Fan motor power, rated current, and voltage.
2. Desired control logic (whether a built-in PLC/DDC is required).
3. Signal type from sensors and control systems (0-10V or 4-20mA).
4. Whether there are special communication protocol or function customization requirements.
5. Requirements for cabinet material, color, and protection level.
VI. Sample diagrams are for reference only.