Feature: 1. MULTI STAGE CONTROL: 8 stage programmable realize multi stage speed control, optional multiple operation modes, simple PLC operation, optional torsion or speed control mode 2. ANALOG INPUT OUTPUT: Come with standard RS485 RTU mode, multiple analog input or output of 0?5v, 0?10v, 4?20ma, 0?20ma 3. CONSTANT PRESSURE WATER AND WIND: Adopt PID control, constant pressure water supply, wind pressure constant pressure control, environmental protection and energy saving, low noise, low electromagnetic interference 4. STEPLESS REGULATION AND ENERGY SAVING: Low frequency and high torsion energy saving, multiple motor protection methods, stepless speed regulation 5. VARIOUS PROTECTION: Possess overcurrent, overvoltage and undervoltage, module failure, overheating, short circuit, input and output phase loss, abnormal adjustment of motor parameters, electronic thermal relay and other protection methods Specification: Item Type: Variable Frequency Drive Model: AT904-4KW Input Voltage: Single phase 220VAC 50/60Hz Output Voltage: Three phase 0-380VAC 0-400Hz Maximum Output Current: 20A Adapted Motor Power: 4KW (6HP) Filter: Built in filter Application: General purpose DC Power Supply Properties: Voltage type Control Mode: V/F open loop Output Voltage Regulation Mode: PWM control Appearance: ABS plastic shell Product Size: Approx. 25 x 18 x 16.5cm / 9.8 x 7.1 x 6.5in(manual measurement with certain error) Uses: Control the start, stop, speed regulation and CW and CCW rotation of the motor to meet the conditions required for production or equipment use, widely used in fans, pumps, air compressors, etc.. Package List: 1 x Variable Frequency Drive1 x User Manual Note: 1. Select a compatible motor to use, you must choose a 380V three phase motor with a power less than 4KW and adjustable speed.2. According to the wiring method of the manual, connect the power supply and the three phase motor.3. Select the appropriate operation mode according to the needs of the application scenario, and refer to the manual for mode selection.4. Power on, the speed of the motor and CW and CCW rotation can be adjusted according to the knob on the panel.