York YST Operation Manual page 47

FORM 160.67-O1
ISSUE DATE: 4/1/2015
governor valve
Displays the present control signal being sent to the
analog output controlling the pneumatically actuat-
ed turbine governor valve. This valve modulates the
steam inlet flow to the turbine to control the speed at
the value shown in the Speed Setpoint display. A 100%
value represents a command for the valve to open fully.
vacuum Solenoid (led)
Illuminates when the vacuum breaker solenoid valve is
energized to open the turbine exhaust to atmospheric
pressure.
Trip Solenoid (led)
Illuminates when the Turbine Trip Valve air dump so-
lenoid valve is energized to open the turbine trip valve.
Turbine rotation (led)
Illuminates when the turbine shaft begins to rotate as
sensed by the Turbine Rotating (Speed Switch) digital
input.
Trip valve limit Switch (open/Closed)
Displays the status of the limit switch sensing the
closed position of the pneumatically actuated turbine
trip valve. The status will change from Open to Closed
after the Trip Solenoid LED illuminates indicating that
limit switch contacts are closed and the valve is open.
nozzle #1 Solenoid (led)
Illuminates when the Turbine Nozzle Valve #1 Air
Dump Solenoid Valve is energized to open that turbine
nozzle valve. This object only appears if MSSP16-Tur-
bine Nozzle Solenoids is set for Enabled or MSSP4-
Turbine Start Mode is set for Auto on Configuration
Screen 1.
nozzle #2 Solenoid (led)
Illuminates when the Turbine Nozzle Valve #2 Air
Dump Solenoid Valve is energized to open that turbine
nozzle valve. This object only appears if MSSP16-Tur-
bine Nozzle Solenoids is set for Enabled or MSSP4-
Turbine Start Mode is set for Auto on Configuration
Screen 1.
JOHNSON CONTROLS
SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
bypass Solenoid (led)
Illuminates when the Steam Inlet Slow Roll Bypass Air
Dump Solenoid Valve is energized to allow the valve to
be opened for slow roll warm-up when the Slow Roll
Valve display is greater than 0%. This object only ap-
pears if MSSP4-Turbine Start Mode is set for Auto and
MSSP19- Governor Valve Location is set for Turbine
on Configuration Screen 1.
Slow roll valve
Displays the present control signal being set to the ana-
log output controlling the Steam Inlet Slow Roll By-
pass Valve. A 100% value represents a command for
the valve to open fully. This object only appears if MS-
SP4-Turbine Start Mode is set for Auto and MSSP19-
Governor Valve Location is set for Turbine on Con-
figuration Screen 1.
inlet Solenoid (led)
Illuminates when the Main Steam Inlet Block Valve
Air Dump Solenoid Valve is energized to allow the
valve to be opened for ramp up to rated speed. This
object only appears if MSSP4-Turbine Start Mode is
set for Auto and MSSP19- Governor Valve Location is
set for Turbine on Configuration Screen 1.
inlet valve
Displays the present control signal being set to the
analog output controlling the Main Steam Inlet
Block Valve. A 100% value represents a command
for the valve to open fully. This object only appears
if MSSP4-Turbine Start Mode is set for Auto and
MSSP19- Governor Valve Location is set for Turbine
on Configuration Screen 1.
inlet limit Switch (open/Closed)
Displays the status of the Main Steam Inlet Valve
Closed Limit Switch. The status will change from
Closed to Open when the Inlet Valve display is greater
than 0% and indicates that the valve has moved off of
the fully closed position and is admitting steam to the
turbine for ramp up to rated speed. This object only
appears if MSSP4-Turbine Start Mode is set for Auto
and MSSP19- Governor Valve Location is set for
Turbine on Configuration Screen 1.
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