York YST Operation Manual page 110

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
This is the maximum Manual speed setpoint allowed
during a mechanical overspeed test. With SSP9-Maxi-
mum Rated Speed set at 4500 RPM, the default value
of 5000 RPM will be displayed as 111.1% in the Man-
ual data field.
SSp7 – Turbine auxiliary oil pump activate
Access Level Required: SERVICE
Screen: Turbine
Range:3000-3500 RPM
This is the speed at which the turbine auxiliary oil pump
will be started during SYSTEM COASTDOWN re-
gardless of the turbine supply oil pressure. It is also the
speed at which the auxiliary oil pump will be stopped
during the ramp up to rated speed if the turbine shaft
driven oil pump is producing sufficient oil flow to in-
crease the turbine supply oil pressure above the PSP9-
Turbine Auxiliary Oil Pump Off pressure. This setpoint
also determines when the Steam Ring Drain Solenoid
Valve is closed during the ramp up to rated speed and
opened during coastdown.
SSp2 – Minimum rated Speed
Access Level Required: TEST OPERATOR/
ADMINISTRATOR
Screen: Steam System
Range: 3200-3600 RPM
This is the minimum speed that the turbine will be al-
lowed to run at during normal operation.
SSp5 – Chilled liquid pump Turn-on Speed
Access Level Required: TEST OPERATOR/
ADMINISTRATOR
Screen: Evaporator
Range: 1000-1600 RPM
The Chilled Liquid Pump Start Contact is closed as
soon as the ramp-to-rated speed is initiated after the
slow roll warm up of the turbine. However, anytime
the speed remains above this value continuously for
the TDSP4 – Chilled Liquid Pump Turn-On Delay, the
Chilled Liquid Pump Start Contact is closed. In some
plants where there is not a dedicated chilled liquid
pump for each chiller, this contact may be used to ini-
tiate the opening of a valve in the chilled liquid inlet
line. In any case, a minimum chilled liquid flow must
be established within the TDSP5- Chilled Liquid Flow
Switch Check Delay in order to avoid a shutdown.
110
Default: 3000 RPM
Default: 3200 RPM
Default: 1500 RPM
SSp9 – Maximum rated Speed
Access Level Required: TEST OPERATOR/
ADMINISTRATOR
Screen: Steam System
Range: 3200-4700 RPM
This is the maximum speed setpoint that the capacity/
anti-surge controls will be allowed to send to the speed
control PID logic during normal operation. This value
is used by the logic as the equivalent to 100% speed.
SSp10 – Maximum Speed analog input
Access Level Required: TEST OPERATOR/
ADMINISTRATOR
Screen: Steam System
Range: 4000-5000 RPM
This is the maximum speed equivalent to a 20 mA in-
put from the frequency-to-analog converter in the Tur-
bine Box and is used for the speed input scaling.
SSp11 – Critical band base Speed
Access Level Required: TEST OPERATOR/
ADMINISTRATOR
Screen: Steam System
Range: 1800-5000 RPM
This is the lower end of the critical speed range of the
Turbine. During ramp up to rated speed, the 17 sec-
ond time delay for the under speed trip logic is initi-
ated when the speed is above this value. If the speed
increases above this value without the ramp to rated
speed being initiated, the turbine is tripped on "Slow
Roll Overspeed".
SSp12 – Critical band offset Speed
Access Level Required: TEST OPERATOR/
ADMINISTRATOR
Screen: Steam System
Range: 500-2000 RPM
This is added to the SSP11- Critical Band Base Speed
value to determine the upper end of the critical speed
range of the Turbine. During ramp up to rated speed, if
the speed does not increase above the upper end of the
critical speed range within 17 seconds from the time it
increased above the SSP11-Critical Band Base Speed
value, the turbine is tripped on "Turbine Underspeed".
FORM 160.67-O1
ISSUE DATE: 4/1/2015
Default: 4500 RPM
Default: 5000 RPM
Default: 2000 RPM
Default: 1000 RPM
JOHNSON CONTROLS