Winco DGC-2020 - Manual (Page 77)

9400200990 Rev B DGC-2020 BESTCOMSPlus Software 4-27
Figure 4-25. BESTCOMSPlus Frequency Protection Settings
A
Underfrequency Pickup: Adjustable from 45 to 66 Hz in 0.1 Hz increments for 50/60 Hz controllers
(style number x1xxxxxxxx). Adjustable from 360 to 440 Hz in 0.1 Hz increments for 400 Hz controllers
(style number x2xxxxxxxx).
B Underfrequency Activation Delay: Adjustable from 0 to 30 s in 0.1 s increments.
C Underfrequency Alarm Configuration: None, Alarm, or Prealarm.
D Underfrequency Inhibit Volts: Adjustable from 70 to 576 Vac in 1 Vac increments.
E
Overfrequency Pickup: Adjustable from 45 to 65 Hz in 0.1 Hz increments for 50/60 Hz controllers (style
number x1xxxxxxxx). Adjustable from 360 to 440 Hz in 0.1 Hz increments for 400 Hz controllers (style
number x2xxxxxxxx).
F
Overfrequency Activation Delay: Adjustable from 0 to 30 s in 0.1 s increments.
G
Overfrequency Alarm Configuration: None, Alarm, or Prealarm.
Overcurrent Protection
Two sets of overcurrent settings are provided: one for three-phase generator connections and one for
single-phase generator connections. The pickup setting entered is based on the CT secondary side
(DGC-2020). When a single-phase override contact input is received by the DGC-2020, the overcurrent
protection settings automatically switch from the three-phase settings to the single-phase overcurrent
protection settings.
When any of the phase currents increase above the pickup setting
A
for the duration of the overcurrent
time delay, an overcurrent condition is annunciated. An overcurrent annunciation can be user-selected to
trigger a pre-alarm
B
(warning) or alarm
B
(shutdown). An overcurrent annunciation can also be user-
configured to close a programmable output.
The overcurrent time delay is controlled by a time dial setting
C
and a curve setting
D
. The curve setting can
be set at F (fixed) or one of 16 inverse time characteristic curves can be selected. When the fixed curve
setting is selected, the time dial setting determines the overcurrent time delay with no regard to the
generator current level. When one of the inverse time characteristic curves is selected, the time dial
setting, along with the level of measured generator current, determines the overcurrent time delay. As
overcurrent protection settings are entered in BESTCOMSPlus, a plot
E of the settings is automatically
created to illustrate the overcurrent pickup curve. The available time characteristic curves are listed below
and illustrated in Appendix A, Time Overcurrent Characteristic Curves.
• A, standard inverse
• I2,
inverse
• A, standard inverse • I2,
inverse
• B, very inverse • L1, long inverse
• C, extremely inverse • L2, long inverse
• D,
definite
• M, moderately inverse
• E1, extremely inverse • S1, short inverse
• E2, extremely inverse • S2, short inverse
• G, long inverse • V1, very inverse
• I1,
inverse
• V2, very inverse
A low-line scale factor setting
F
is used to automatically adjust the overcurrent pickup settings in
applications that may utilize more than one type of genset connections. The scale factor setting is
implemented when the DGC-2020 senses a contact closure at a contact input programmed to activate
scaling of the protection settings. The value of the scale factor setting serves as a multiplier for the pickup