14
Electric Power Generation
2019.10 / e
Installation and maintenance
R180
AVR
5599 en -
8.3 - Test procedure
1. Build-up test
To test build-up, start the variac at 0 volts
and set the output voltage to around 5 VAC
between X1 and X2. If the AVR is OK, the DC
voltmeter will display a stable value between
terminals F1 and F2 on the AVR which will
increase as the input power increases.
2. Voltage control test
The default AVR voltage setpoint is around
415 VAC. The bulb should remain ON for a
supply voltage level below the setpoint i.e.
around 415 VAC and should turn OFF when
the input voltage is increased above the
setpoint by the variac. The bulb transition
will be gradual because the AVR is stable.
3. External potentiometer test
Connect the 1 K potentiometer between
terminals A1 and A2. The external
potentiometer will allow the setpoint to drop
to 330 V from 415 V (minimum and maximum
positions). This can be verified by the
voltage control test described above.
4. UFRO test
Set the variac output voltage to 400 VAC.
The bulb will up light because the setpoint is
415 V. Now turn on the switch which is
connected to the 50 Hz/60 Hz input. The
bulb will gradually go OFF due to the change
in the UFRO setpoint. If the switch is turned
OFF the bulb will light up again. In 60 Hz
mode the UFRO LED will light up.
5. Sensing loss test
Open connection W on the AVR terminal
and start the AVR at 400 V. The sensing loss
LED will light up and the bulb will be ON for
5 sec and then switch OFF.
6. Stability test
The bulb dimming rate during the voltage
control test depends upon the AVR stability
setting. At minimum stability, the bulb will
switch ON and OFF around the voltage
setpoint. A higher stability setting will
decrease the speed of bulb dimming and
brightening.
7. Voltage range
The AVR voltage range can be checked by
performing a voltage control test for V
potentiometer min and V potentiometer
max. This test gives the approximate voltage
range values.
8. UFRO test
The UFRO factory setpoint is around
47.5 Hz. Set the variac output to 410 VAC.
Turn the UFRO potentiometer clockwise
until the UFRO LED turns ON. One more
clockwise turn of the UFRO potentiometer
will gradually switch OFF the bulb.
