Installation Guide

2022.02 / j
7
Electric Power Generation
Installation and maintenance
R150
AVR
5384 en -
5 - AVR SETTINGS
5.1 - V-TRIM (V)
This function is provided for setting the
voltage up to ± 12% of rated voltage by
means of a potentiometer. Turn the
potentiometer clockwise to increase the
voltage and vice versa, once the rated
speed has been reached.
It is also possible to connect an external
potentiometer.
5.2 - UNDER FREQUENCY KNEE
POINT SETTING (UF)
This function is provided to protect the
AC generator from sustained low speed
operation through a potentiometer. The AVR
will reduce the voltage in proportion with the
speed below the dened value. The
procedure for setting the UF potentiometer
is as follows: First run the generator at full
speed (50 Hz) and turn the UF potentiometer
by a few turns clockwise, making sure that
the voltage does not increase. Now turn the
UF potentiometer slowly anticlockwise. At a
particular point the red LED glows and the
voltage will start to decrease. Stop turning
the potentiometer at this point and turn the
potentiometer clockwise by two turns after
rated voltage is restored.
The factory default setting is 46 Hz.
For 60 Hz operation, the knee point position
is set to 56 Hz.
5.3 - STAB (S)
This function is provided to stop voltage
hunting by means of a potentiometer. Turn
clockwise to increase stability (to stop
oscillation). Turning too far clockwise will
result in a sluggish response and possibly
also oscillations.
The factory default setting is slightly
higher than critical damping (around
halfway).
5.4 - QUADRATURE DROOP
This potentiometer is used to adjust the
voltage droop to balance the reactive load in
parallel operation. Follow the instructions
for connecting the CT (current transformer)
which is essential for this function, as per the
AVR connection diagram.
Turn the potentiometer clockwise to
increase % droop and vice versa.
5.5 - A1&A2 DC VOLTAGE INPUTS
(AC)
These accessory terminals A1 and A2 are
used to inject ± 1 to 4.5 VDC. The variation
in terminal voltage will be ± 10% of the rated
voltage.
Warning: A “Vishay spectrol model 8”
type screwdriver should be used to
adjust the potentiometer.
6 - AVR CONTROLS
No. Control Function Direction
V VOLTS Sets the generator output voltage Turn clockwise to increase output voltage
UF UFRO Sets the Under frequency knee point Turn clockwise to reduce the knee point
S STAB Stops voltage hunting Turn clockwise to increase stability
DROOP DROOP Sets voltage droop Turn clockwise to increase the droop
AC ACC (DC i/p) Used for Auto synchronization Turn clockwise to increase the gain