Manual 35018V1
505XT Digital Control System for Steam Turbines
Woodward
166
The Speed Control screen will adapt to the configuration of the 505XT and show all configured options.
During normal run operation, this screen provides the user with all details that are related to the turbine
when operating in speed control.
The menu bar functions will allow the user to access a number of other screens that are related to speed
control, such as directly entering a setpoint, access to the valve limiter feature, adjusting speed control
dynamic settings, enabling or disabling a remote speed setpoint or performing an Overspeed test. For
generator units the breaker status of the breakers is shown and the menu bar will give the user access to
Enabling the synchronizer.
Valve Demand Screen
Figure 5-12. Valve Demand Screen
The Valve Demand screen will adapt to the configuration of the 505XT and show all configured options
that can affect the final output demand to the HP valve. For Ext/Adm turbine configurations, it will have a
navigation button to switch to the LP valve demand. During normal run operation, this screen provides
the user with a clear picture of what control or ramp is controlling the valve demand output. The Low
Signal Select (LSS) bus will output the lowest value seen at its inputs. The valve logic box represents
options that may be use to adjust this value (such as valve linearization and/or pressure compensation)
prior to output to the HP valve. If these options are not used, the HP valve demand output will always
equal the LSS value.
During normal operation the Valve Limiter setting is at 100% and not limiting.
Typically, the only time this parameter is adjusted is during a start sequence or to troubleshoot system
dynamics problems.
The menu bar will allow the user to access the valve limiter setpoint and the manual valve demand (if
configured for use).