Fault Analysis of RS8621F Linear Isolation Amplifier Board in DC Control and Protection System

The RS8621F board is a 4-channel linear isolation amplifier board for voltage measurement, which converts the acquired AC-DC low voltage analog into digital data and sends it to the PCS series DC control and protection system. In recent years, there have been many 59ACVW protection abnormal alarm events caused by abnormal measurement of RS8621F board. In this paper, the fault cause is analyzed in combination with the board circuit, and the fault cause is located as the optocoupler. By testing and replacing the optocoupler, the correctness of the fault analysis conclusion is verified.