NTHS03 | ABB Bailey Infi 90 Hydraulic Servo Termination Unit

The NTHS03 Hydraulic Servo Termination Unit is a Harmony rack I/O device that is part of the Symphony Enterprise Management and Control System. It provides a signal path between an IMHSS03 Hydraulic Servo Module and a hydraulic servo valve, I/H converter, or linear variable differential transformer. The IMHSS03 module is a position control module through which a rack controller can control a hydraulic actuator via a servo valve. By regulating the current to the servo valve, it initiates a change in actuator position. A linear variable differential transformer (LVDT) provides actuator feedback to the IMHSS03 module via the NTHS03 termination
unit. Typical uses for this hardware are positioning steam turbine throttle and control valves, gas turbine fuel valves, inlet
guide vanes, and nozzle angle. Figure 1-1 shows the Harmony rack I/O architecture. A Harmony area controller and the Harmony rack controllers can use the rack I/O module and termination units for I/O interface.