Views: 0 Author: Site Editor Publish Time: 2025-08-28 Origin: Site
Against the backdrop of industrial automation and energy-saving retrofits, inverters have become indispensable core equipment in fan and pump systems. They not only enable flexible motor start and speed control but also significantly improve system operation efficiency and reduce energy consumption. Faced with a wide variety of inverter products on the market, selecting the right inverter for specific industry applications is a key issue for every equipment engineer and procurement manager to consider.
Load Type
Fans and pumps mostly belong to the category of quadratic torque loads (airflow or water flow ∝ speed, power ∝ speed³). These loads require low power at low speeds and rapidly increasing power at high speeds.
Application Scenarios
Fans: HVAC, dust removal systems, cooling systems, etc.
Pumps: Municipal water supply, building water supply, circulation water systems, wastewater treatment, etc.
Energy-Saving Potential
By adjusting motor speed to precisely control flow or airflow, 20%–60% energy savings can be achieved compared to traditional valve throttling methods.
Motor Power and Voltage Level
The inverter’s rated power must match the motor’s power, with a recommended 10%–20% margin to cope with voltage and load fluctuations during actual operation. Common voltage levels: 220V single-phase input, 380V three-phase input (most commonly used for industrial pumps and fans).
Overload Capacity
Most fan and pump applications operate steadily and don’t require high overload capacity. Typically, 110%–120% overload capacity is sufficient. For applications with frequent starts/stops or momentary impact loads (e.g., fire pumps), inverters with higher overload capacity are required.
Speed Control Range
For ordinary pump and fan applications, a speed control range of 30Hz–50Hz is usually sufficient. For applications requiring wide-range speed control (e.g., special process circulating pumps), models supporting a wide frequency range (5Hz–60Hz) are recommended.
Control Methods
V/F Control: Suitable for general constant-pressure water supply and fan air delivery, cost-effective and simple.
Vector Control (with or without PG): Suitable for conditions with stable pressure and flow requirements, offering high speed control accuracy and fast dynamic response.
Protection Level and Environmental Adaptability
Most pumps and fans are installed in indoor equipment rooms, where IP20–IP21 protection is adequate. For humid or dusty environments (e.g., wastewater plants, mining fan rooms), inverters with IP54 or higher protection level should be selected.
PID Control Function
For constant-pressure water supply and constant-airflow systems, the inverter should have a built-in PID controller to automatically adjust and maintain system pressure or flow.
Multi-Pump/Fan Switching and Linkage Control
In water supply and ventilation scenarios, multiple pumps or fans often operate in parallel. The inverter should support multi-pump switching to realize “one-to-many” or automatic rotation among multiple units, thus extending equipment life.
Soft Start and Protection Functions
Avoids current impact and water hammer effect caused by traditional direct start, extending pipeline and motor life. The inverter should feature complete protection functions such as overcurrent, overvoltage, undervoltage, phase loss, and overheating.
Communication and Intelligence
Support for communication protocols such as Modbus, Profibus, BACnet, etc., for easy integration with building automation or industrial control systems to enable remote monitoring and intelligent operation.
High-Rise Building Water Supply System
Recommended: inverters with specialized constant-pressure water supply functions, supporting multi-pump control, power range typically 5.5kW–75kW.
Central Air Conditioning Fan System
Recommended: models with PID auto-adjustment and communication interfaces, capable of integration with building management systems (BMS), power range typically 7.5kW–90kW.
Wastewater Treatment Plant Pumps
Due to harsh environments, inverters with high protection level and corrosion resistance are needed. Vector control is also necessary to ensure stable operation.
As typical quadratic torque loads, fans and pumps mainly require inverters that are energy-efficient, reliable, and user-friendly. In actual selection, focus on:
Parameter Matching: Motor power, voltage level, overload capacity.
Functional Matching: PID control, multi-pump linkage, communication protocols.
Environmental Adaptation: Protection level and installation environment.
Correct selection and application of inverters can not only significantly reduce energy consumption but also enhance the stability and lifespan of the system, creating greater economic benefits for enterprises.
