DATAKOM DKG-705 User’s Manual
705_USER.doc
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6.2 AVR Control
The voltage matching is controlled by the alternator’s AVR module. The DKG-705 compares the
mains phase R voltage with the genset phase U voltage.
The AVR control output (terminals 43-44) is similar to an isolated variable resistor. Usually all
brands and types of AVR accept an external adjustment potentiometer. The AVR control will use these
inputs, thus the DKG-705 is able to control most of the AVRs found on the market.
The impedance range of the AVR output is 300 ohms to 200 K-ohms. The range is adjustable with
an internal potentiometer accessible from the back panel of the unit.
The functions of the AVR output are controlled by programmed parameters:
P_A04 AVR Control Enable:
This parameter enables/disables the activation of the AVR control output. If
AVR control is disabled, the output will always stay at the rest level defined by
P_A14
.
P_A05 AVR Reverse Polarity:
In normal polarity, the AVR control impedance decreases in order to
increase the alternator voltage. If reverse polarity is selected the AVR impedance increases in order to
increase the alternator voltage.
P_A14 AVR Start:
This is the rest value of the AVR control impedance. Always set this value to 160 and
then adjust the alternator voltage with the AVR’s control pot. However, if needed, alternator voltage
adjustment may be made through this parameter. Do not forget that, if this parameter is modified, the
adjustment range will be reduced.
P_A16 AVR Gain:
This parameter defines the reaction speed of the AVR output to voltage differences
between genset and mains phases during synchronization. The standard value for this parameter is 64.
But it must be readjusted for the genset during manufacturing. If this parameter is too high, a voltage
oscillation may occur. If it is too low, the voltage matching will be slower.
