Position of adjustments
Control
Function
Direction
Volts
To adjust generator output voltage
Clockwise increases output voltage
Stab.
To prevent voltage hunting
Clockwise increases the damping effect
Stability selection
To optimise transient performance
See table
UFRO
To set Under Frequency Roll Off knee point
Clockwise reduces knee point frequency
UFRO select 50 / 60
To set UFRO control range
Switch position 5 = 50 Hz 6 = 60 Hz
Droop
To set voltage droop to 5% at 0 PF
Clockwise increases the droop
Trim
To match AVR input to Accessory output
Clockwise increases AVR sensitivity
Dip
To adjust frequency related voltage dip
Clockwise increases the dip
Dwell
To set the rate of voltage recovery time
Clockwise lengthens the recovery time
Mode
To select AVR or hand control mode
8 = AVR control. 4 = Hand control
Ramp
To set the soft start voltage ramp time
Clockwise lengthens the ramp time
O / Ex (sealed)
To adjust over excitation trip level
Clockwise increases the trip level
O / V (sealed)
To set over voltage protection trip level
Clockwise increases the level
PWL (sealed)
To set the maximum excitation voltage limit
Clockwise increases the voltage limit
Hand (sealed)
For manual excitation control
Clockwise increases excitation
Overload detector
continuously monitors the excitation
voltage and provides signals to shutdown the AVR power
output device and trip an optional circuit breaker if the
threshold setting is exceeded.
The circuit breaker isolates power from the exciter and AVR
power devices if sustained over-excitation occurs. An
overload condition produces a latched fault requiring the
generator to be stopped for reset
Over-voltage monitor
continuously monitors the voltage at
the AVR terminals and provides signals to shut down the AVR
power output device and trip an optional circuit breaker.
The circuit breaker isolates power from the exciter and AVR
power devices if sustained over-voltage occurs. A fixed one
second timer is included in the circuit to prevent operation
during transient over-voltages, which are normal after load
removed. The generator must be stopped to reset an over
voltage trip.
Voltage adjustment
The generator output voltage is set at the factory, but can be
altered by careful adjustment of the volts control on the AVR
board, or by the external hand trimmer if fitted.
WARNING!
DO NOT INCREASE THE VOLTAGE ABOVE THE RATED
GENERATOR VOLTAGE. IF IN DOUBT, REFER TO THE
RATING PLATE MOUNTED ON THE GENERATOR CASE.
If a replacement AVR has been fitted or re-setting of the
VOLTS adjustment is required, proceed as follows:-
Before running generator, turn volts control fully anticlockwise.
Turn remote volts trimmer (if fitted) to midway position.
Turn stability control to midway position.
Connect a suitable voltmeter across line to neutral of the
generator.
Start generator set, and run at a no-load condition at nominal
frequency e.g. 50-53 Hz or 60-63 Hz.
If the red light emitting diode (LED) is permanently
illuminated, refer to the under frequency roll off adjustment
(UFRO).
If the LED is flashing then refer to Over Excitation and Over-
Voltage protection adjustments.
Carefully turn the VOLTS control clockwise until rated voltage
is reached.
If voltage instability is present at rated voltage, refer to the
Stability adjustment, then re-adjust voltage if necessary.
Voltage adjustment is now complete.
