Rev. 1.00
22585_EDEBD
A0252-0318-1_EN
8
KBR multicomp F144-3 6DO/12DO
Functional principle
1
Functional principle of the controller
The controller's microprocessor records the mains voltage and current con-
sumption of the entire plant by measuring transformer inputs (A/D converter)
and, on the basis of this, calculates the active and reactive power ratio of the
power supply. The controller operates in four quadrants.
Energy recovery in generator operation is detected and indicated by a "G"
flashing on the LCD display. While in generator operation, compensation to
cos phi 1.00 (output cos phi) is performed. To prevent alternating switching
operations, this target cos phi is maintained for 15 minutes after generator
operation ends.
The compensated power required for the target cos phi is calculated contin-
uously. If the power difference corresponds to the set hysteresis (switch-on
and switch-off hysteresis), the stages are switched depending on the required
compensation power. Manually switched stages are, however, not included in
the optimization. In case of identical stages with identical power, the stage that
has been switched off for the longest time is switched on.
Having fewer switching operations results in optimum adjustment. Even for
large systems, sensitive controls can be set up with just a few modules. Stage
ratios do not need to be considered. After compensation, switching operations
are interrupted for a configurable time. To prevent alternating switching opera-
tions, you can increase the stage switch-off delay by up to 150% of the smallest
stage's power.
In light load operation (secondary measuring current under the limit), the stag-
es are switched off after the set delay time.
The integrated temperature measurement input monitors the temperature in
the reactive power compensation system and causes the fan to be switched on
if a predefined temperature threshold is exceeded and switched off again when
the temperature drops below the reset temperature.
To prevent the fan from switching unnecessarily often, it has a run-on time of
30 minutes. You can switch the fan (output 6 or 12, depending on the device
version) on or off permanently in the "Stage state" menu. If you select "Auto",
the fan output is controlled by the temperature measuring input.
You can also protect the system by defining a switch-off temperature. This
makes it possible to switch stages off in time if there is a risk of damage due
to overheating. Once the temperature drops below the reset temperature, the
stages are switched on again one after the other.
