Winco DGC-2020 - Manual (Page 79)

9400200990 Rev B DGC-2020 BESTCOMSPlus Software 4-29
to transfer the load back to the mains once mains power is restored. Settings include a transfer delay D ,
return delay
E
, and max transfer time
F
.
Breakers controlled by pulse or continuous inputs are supported G . Separate settings for each breaker’s
open H and close I pulse widths are provided.
During synchronization of the generator with the bus (Anticipatory mode only), the DGC-2020 uses the
breaker closing time
J to calculate the optimum time to close the breaker.
When a close command is issued, the DGC-2020 monitors the breaker status and annunciates a breaker
failure if the breaker does not close within the time defined by the breaker-close wait-time delay
K
.
Typically, this parameter is set to be longer than twice the breaker closing time.
Figure 4-27. BESTCOMSPlus Breaker Hardware Settings
A
Generator Breaker: Always configured, not user-adjustable.
B
Mains Breaker: Configured or NOT Configured.
C
Mains Fail Transfer: Enable or Disable. This setting does not apply when generator frequency is
400Hz.
D
Mains Fail Transfer Delay: Adjustable from 1 to 300 s in 1 s increments.
E Mains Fail Return Delay: Adjustable from 0 to 1,800 s in 1 s increments.
F Mains Fail Max Transfer Time: Adjustable from 10 to 120 s in 1 s increments.
G
Contact Type: Continuous or Pulse.
H
Open Pulse Time: Adjustable from 0.01 to 0.80 s in 0.01 s increments.
I
Close Pulse Time: Adjustable from 0.01 to 0.80 s in 0.01 s increments.
J
Breaker Closing Time: Adjustable from 0 to 800 ms in 5 ms increments.
K
Breaker Close Wait Time: Adjustable from 0.1 to 600 s in 0.1 s increments.
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 Time 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 Time Delay. 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 Time Delay setting.
NOTE
Voltage threshold and pickup settings on the Bus Condition Detection screen are
entered in primary values (generator side of VT).