Basler Electric DECS-100 - Manual (Page 31)

9287500991 Rev M DECS-100 Functional Description 3-7
The alarm time delay is adjustable from 0 to 10 seconds.
NOTE
The UEL function is active only during parallel operation when the 52J/K
contact input or 52L/M contact input is open.
Soft Start
The DECS-100 also incorporates an adjustable soft start feature that controls the time for generator
voltage or field current to ramp to the regulation setpoint. The ramp rate is adjustable from 1 to 7,200
seconds in 1 second increments through BESTCOMS. The underfrequency feature is also active during
soft start and takes priority in control of the generator voltage in an effort to minimize voltage overshoot.
Voltage Matching (Optional)
Voltage matching is useful when the PT ratios in an application are not matched exactly. Using
BESTCOMS to enter the generator PT ratio and bus PT ratio will automatically compensate for the offset.
The DECS-100 voltage matching option automatically matches the rms generator output with the rms bus
voltage prior to synchronizing. The DECS-100 compares and matches the generator voltage with the bus
voltage by adjusting the dc excitation current. Voltage matching is enabled when the bus voltage input is
within 10% of the nominal generator secondary input sensing range selected. As long as the values of
generator and bus voltage (applies secondary voltage to the DECS-100 voltage sensing inputs) are within
the acceptable range, voltage matching can be achieved.
The rate at which the DECS-100 matches the generator input level with the bus input level is controlled by
a voltage matching speed setting. this setting is adjustable from 1 to 300 seconds in 0.01 second
increments.
Voltage matching can be disabled by the state of the DECS-100 contact inputs. In BESTCOMS, the
52J/K contact input, 52L/M contact input, or both contact inputs can be configured to enable and disable
voltage matching. To enable bus voltage matching, select 52J/K. This will allow droop to remain active.
When the utility tie breaker closes, voltage matching will be disabled automatically (via the 52J/K contact
input) and var/power factor control will be enabled.
Two voltage matching modes are available: Maintain and Revert. When Maintain mode is implemented,
the DECS-100 setpoint is maintained at the bus voltage level even when the generator or utility breaker is
open. When Revert mode is implemented, the DECS-100 setpoint reverts to its original level when the
generator or utility breaker opens. Revert is the default voltage matching mode.