Basler Electric DGC-2020HD - Manual (Page 163)

9469300990 Rev B 153
Arming Delay
A user-adjustable arming delay disables configurable protection during engine startup. If the arming delay
is set to zero (0), the configurable protection is active at all times, including when the engine is not
running. If the arming delay is set to a non-zero value, the configurable protection is inactive when the
engine is not running, and does not become active until after the engine is started and the arming delay
has elapsed.
Hysteresis
This setting provides a level of hysteresis between a threshold detection tripping and dropping out. For
instance, if the hysteresis is set for 5% and the threshold is set as an over threshold, once the threshold
detection trips, the measured parameter must drop to 95% of the threshold before the threshold detection
will drop out. This hysteresis helps prevent rapid or repeated transitions between trip and dropout in
cases where the measured parameter is nearly equal to a level equal to the threshold.
If the threshold is set as an under threshold with 5% hysteresis, once the threshold detection trips, the
measured value must rise to 105% of the threshold before the threshold detection will drop out.
Scale Factors
Alternate Frequency Scale Factor
Alternate frequency scale factor is used when any Generator, Bus 1, or Bus 2 frequency-based parameter
is selected as the parameter for configurable protection.
Voltage Low-Line Scale Factor
Voltage low line scale factor is used when the parameter selection for configurable protection is set for
any Generator, Bus 1, or Bus 2 line-to-line or line-to-neutral voltage parameter.
Current Low-Line Scale Factor
Current low line scale factor is used when the parameter selection for configurable protection is set for
any Generator, Bus 1, or Bus 2 current parameter.
Thresholds
There are four programmable thresholds for each remote analog input element. Each threshold has a
mode setting, threshold setting, activation delay setting, and an alarm setting.
Alarm Configuration
Each configurable protection threshold item can be independently configured to annunciate an alarm or
pre-alarm, or be configured as status only when the parameter selection falls beyond the threshold. A
user-adjustable activation delay setting delays alarm annunciation until after the threshold has been
exceeded. Configurable protection is disabled when Alarm Configuration is set to “None”.
Note
The Arming Delay should not be set to zero if Oil Pressure or Battery
Volts is selected for configurable protection and the threshold is set to
monitor for conditions lower than the threshold and the alarm
configuration is set to Alarm. Setting the arming delay to zero will
cause an immediate alarm on the oil pressure, and engine cranking
could cause a temporary low battery voltage condition which could
cause an alarm. In either case, the spurious alarm would prevent the
engine from starting.
DGC-2020HD Configurable Protection