This device is a three-level middle point box structure, easy to operate, perfect protection function and high intelligence. It has the following characteristics: 1. With complete protections, such as over-voltage, undervoltage, over-current, phase missing, short circuit, overload, overheating, underload, etc.
2. With LED display, displaying output current, voltage, frequency, failure reasons, etc.
3. System parameters can be set through the keyboard.
4. Operating conditions can be monitored through the communication with the computer.
5. Voltage, current and frequency monitoring signals can be provided.
6. Start time and running frequency can be set arbitrarily.
7. Digital or analog current recorder for the electric pump unit can be provided to monitor its operating conditions.