Manual 35018V1
505XT Digital Control System for Steam Turbines
Woodward
170
Exhaust Control Screen
Figure 5-18. Exhaust Pressure Control Screen
The Exhaust Pressure Control screen will adapt to the configuration of the 505XT. During normal run
operation, this screen provides the user with all details that are related to the exhaust pressure control
loop. This can be configured as a limiter or a controller, depending on the turbine type.
On a single valve turbine is can be setup as a limiter, during which it will always be enabled and provide
protection related to the process variable being used for this function. When configured as a controller it
will disable the speed PID whenever it’s enabled. The exhaust pressure control output goes to the LSS
bus and can directly affect the HP valve demand output.
On an Ext/Adm turbine this is always a controller and the output of this PID goes into the Ratio Limiter
logic, where it can be used in alternate control modes as a primary or secondary controller.
The menu bar functions will allow the user to access a number of other screens that are related to
exhaust pressure control, such as directly entering a setpoint, access to the valve limiter, or adjusting
exhaust pressure control dynamic settings.
Steam Map Screen
Figure 5-19. Steam Map Screen