DECS-100 BESTCOMS for Windows
®
OS
5-14
Figure 5-17. Metering, Operation, and Alarms, Operation Tab
Loss of Sensing Voltage - Hardware Shutdown. Enabling Hardware Shutdown will cause the DECS-100 to
remove field excitation when a loss of sensing voltage occurs. Disabling Hardware Shutdown prevents the
DECS-100 from removing excitation during a loss of sensing voltage.
Generator Overvoltage - Voltage Level (%). The value of this field is expressed as a percentage and
determines the level of generator voltage required to initiate a generator overvoltage condition. An
overvoltage percentage value of 100 to 120 percent may be entered in 1 percent increments. A generator
overvoltage condition lights the GENERATOR OVERVOLTAGE LED on the front panel and closes the Alarm
output at DECS-100 terminals AL1 and AL2.
Generator Overvoltage - Hardware Shutdown. Enabling Hardware Shutdown will cause the DECS-100 to
remove field excitation when the generator overvoltage setting is exceeded. Disabling Hardware Shutdown
prevents the DECS-100 from removing excitation during a generator overvoltage condition.
Metering, Operation and Alarms
The Metering, Operation and Alarms screen is viewed by clicking the Metering button or by clicking Screens
on the Menu bar and clicking Metering/Operation. Information displayed on the Metering, Operation and
Alarms screen can be frozen by clicking the Metering button while viewing the screen or by clicking Metering
on the Menu bar and clicking Disable Metering. Metering can be resumed by clicking the Metering button or
by clicking Metering on the Menu bar and clicking Enable Metering. The Metering, Operation and Alarms
screen consists of two tabs: Operation and Alarm/Status.
Operation Tab
Operation tab metering values, setpoint values, and control functions are illustrated in Figure 5-17.
Gen Voltage (V). These metering values report the status of the V
A-B
, V
C-B
, V
C-A
, and V
AVG
generator voltages.
The reported values are the product of the voltage sensed at terminals E1, E2, and E3 and the generator PT
ratio. All metering values are updated once each second. When single-phase sensing is used (System
Configuration screen, Sensing Voltage) and the DECS-100 sensing voltage terminals (E1, E2, and E3) are
connected as shown in Figures 4-7 or 4-9, all of the generator voltage metering values will be identical.
Gen Current (A). This metering value indicates the level of the B-phase generator current. This value is the
product of the current input to CT1 and CT2 and the CT ratio. Generator current is monitored through
DECS-100 terminals CT1 and CT2.