Original Hitachi Screw Chiller Main Control PCB Board suitable for Hitachi screw chiller systems. This controller board is identified by PCB numbers C0971-B3, C0971-3, C0971-SA3, C0971-A3, 80H1A, C-387, 169KB F. It controls compressor operation, communication, safety protection, sensors, relays, and chiller functions. Ideal for replacement, repair, and maintenance of Hitachi screw chillers. Matching the PCB number before ordering is recommended.