Winco DGC-2020 - Manual (Page 123)

E Mains Fail Return Delay: Adjustable from 0 to 1,800 s in 1 s increments. This specifies the delay
between detection of restored (stable) mains and initiation of the return from the generator back to the
mains.
F Mains Fail Max Transfer Time: Adjustable from 10 to 120 s in 1 s increments. This specifies the
maximum time that is allowed for a transfer from failed mains to generator power. If the transfer has not
been achieved in this time, a Mains Fail Transfer Fail pre-alarm is annunciated and the transfer is
aborted. The pre-alarm can be cleared by switching to OFF mode or pressing the Reset button on the
front panel of the DGC-2020. Note that the Mains Fail Max Transfer Time setting must be longer than the
time for the Mains Fail Transfer Delay plus the Sync Activation Delay plus the Breaker Close Wait Time.
G Contact Type: Continuous or Pulse. If Continuous is selected, the outputs will be on during the time
that the desired Close or Open condition is in effect. If Pulse is selected, the duration of the pulses are set
by the Open Pulse Time and Close Pulse Time settings.
H Open Pulse Time: Adjustable from 0.01 to 0.80 s in 0.01 s increments. This setting applies only when
Contact Type is Pulse. This time should be ≥ the Breaker Closing Time setting.
I Close Pulse Time: Adjustable from 0.01 to 0.80 s in 0.01 s increments. This setting applies only when
Contact Type is Pulse. This time should be ≥ the Breaker Closing Time setting.
J Breaker Closing Time: Adjustable from 0 to 800 ms in 5 ms increments. This specifies the amount of
time the breaker takes to close once a close contact is applied to it. This time is used for anticipatory
synchronization to issue a close pulse a certain time before the 0 degree slip angle is reached so that
when the breaker actually closes, the slip angle is near 0 degrees.
K Breaker Close Wait Time: Adjustable from 0.1 to 600 s in 0.1 s increments. This specifies the amount of
time the DGC-2020 will wait between issuing a close pulse to a breaker and expecting the breaker status
to be indicated as closed. If this time expires before the breaker status is indicated as closed, a Breaker
Close Fail pre-alarm will be annunciated. The pre-alarm can be cleared by switching to OFF mode or
pressing the Reset button on the front panel of the DGC-2020.
L Dead Bus Close Enable: Enable or Disable.
Bus Condition Detection
DGC-2020 detection of dead bus voltages (for dead bus breaker closure) is controlled by a Dead Bus
Threshold setting
A and a Dead Bus Activation Delay setting B . A dead bus is recognized when the voltage
decreases below the threshold setting for the duration of the time delay setting.
Before the DGC-2020 initiates a breaker closure, the generator and mains voltages must be stable. The
DGC-2020 uses several settings to determine voltage stability. These settings include pickup and dropout
levels for overvoltage
C , undervoltage D , overfrequency E , and underfrequency F . Recognition of bus stability
is further controlled by two timers. Voltage conditions must meet the stability pickup and dropout settings
for the duration of the Bus Stable Activation Delay
G . Breaker closure is not considered if the voltage
conditions do not meet the stability pickup and dropout settings for the duration of the Bus Failed
Activation Delay
H setting.
The Bus Stable and Gen Stable overvoltage and undervoltage detection elements have the low line scale
factor
I applied to them to enhance versatility for reconfigurable machines.
NOTE
Voltage threshold and pickup settings on the Bus Condition Detection screen are
entered in primary values (generator side of VT).
BESTCOMSPlus bus condition detection settings (DGC-2020, Breaker Management, Bus Condition
Detection) are illustrated in Figure 4-50.
9400200990 Rev K DGC-2020 BESTCOMSPlus Software 4-53