Basler Electric DECS-400 - Manual (Page 51)

9369700990 Rev R 39
DECS-400 can be configured to transfer to FCR mode when a loss of sensing voltage condition is
detected. Two Level settings are provided: Balanced Level and Unbalanced Level. When all three phases
of sensing voltage decrease below the Balanced Level setting, the Delay timer begins timing out.
Balanced Level settings are adjustable from 0 to 100% (of nominal generator voltage) in 0.1 percent
increments. When the difference between nominal generator voltage and any one of the three phases of
sensing voltage exceeds the Unbalanced Level setting, the Delay timer begins timing out. Unbalanced
Level settings are adjustable from 0 to 100% (from nominal generator voltage) in 0.1 percent increments.
The Delay timer setting is adjustable from 0 to 30 seconds in 0.1 second increments. Loss of sensing
voltage protection can be enabled and disabled without altering the Level and Delay settings.
Loss of Field Isolation Transducer
A loss of field isolation transducer condition is annunciated when the field voltage or field current signal
from the isolation module decreases below a predetermined level for the duration of the Loss of Field
Isolation Transducer Delay setting. The Delay setting is adjustable from 0 to 9.9 seconds in 0.1 second
increments.
Generator Frequency Less Than 10 Hertz
A below 10 Hz condition is annunciated when the generator frequency, measured across phases A and C
(V
CA ), decreases below 10 Hz. A below 10 Hz annunciation is automatically reset when the generator
frequency increases above the 10 Hz threshold.
Power Supply Low
A low power supply condition is annunciated when the internal power supply levels decrease below a pre-
determined level. A low power supply annunciation is automatically reset when the internal power supply
voltage increases above the preset threshold.
Loss of Field (40Q)
A loss of field (excitation) condition is annunciated when the reactive power absorbed by the generator
exceeds the Loss of Field Pickup Level setting for the duration of the Loss of Field Delay setting. The
Loss of Field condition will continue timing until the reactive power absorbed by the generator decreases
below the dropout ratio (95%). The Pickup Level setting is adjustable from 0 to 3,000,000 kvar (leading) in
1 kvar increments. The Delay setting is adjustable from 0 to 9.9 seconds in 0.1 second increments. Figure
7 illustrates the generator capability curve versus the loss of field function’s response. Figure 8 illustrates
the motor/condenser capability curve versus the 40Q function’s response.
DECS-400 Functional Description