©2006 1 TD_AS440 AVR_09.06_03_GB
AS440 AUTOMATIC VOLTAGE
REGULATOR (AVR)
SPECIFICATION INSTALLATION AND ADJUSTMENTS
General description
Technical specification
AS440 is a half wave phase controlled thyristor type AVR
and forms part of the excitation system for a brushless
generator. The design employs Surface Mount Technology
(SMT) for high integration of features in a small footprint
AVR.
Positive voltage build up from residual levels is ensured by
the use of efficient semiconductors in the power circuitry of
the AVR. The power and voltage sensing circuits have
separate terminals, allowing the excitation power to be
derived directly from the stator winding for basic
applications or from an auxiliary winding if sustained short
circuit performance is required.
The AVR is linked with the main stator windings and the
exciter field windings to provide closed loop control of the
output voltage with load regulation of +/- 1.0%.
The AVR voltage sensing terminals continuously sample
the output windings for voltage control purposes. In
response to this sample voltage, the AVR controls the
power fed to the exciter field, and hence the main field, to
maintain the machine output voltage within the specified
limits, compensating for load, speed, temperature and
power factor, of the generator.
A frequency measuring circuit continually monitors the
generator output and provides under-speed protection of
the excitation system, by reducing the output voltage
proportionally with speed below a pre-settable threshold. A
manual adjustment is provided for factory setting of the
under frequency roll off point, (UFRO). This can easily be
changed to 50 or 60 Hz in the field by push-on link
selection.
Over excitation conditions are limited to a safe period by a
protection circuit within the AVR.
Provision is made for the connection of a remote voltage
trimmer, allowing the user fine control of the generator's
output.
An analogue input is provided allowing connection to the
Power Factor controller or other external devices with
compatible output.
The AVR has the facility for droop CT connection, to allow
parallel running with other similarly equipped generators.
SENSING INPUT
Voltage Jumper selectable
100-130 Vac 1 phase or
190-264 Vac 1 phase
Frequency 50-60 Hz nominal
POWER INPUT
Voltage 100-264 V ac 1 phase
Frequency 50-60 Hz nominal
OUTPUT
Voltage 82 V d.c. @ 200 V a.c.
Current continuous 4A (see note 1).
transient 7.5A for 10 secs.
Resistance 15 ohms min
(10 ohms min when input
volts is less than 175 ac)
REGULATION
+/- 1.0% (see note 2)
THERMAL DRIFT
0.03% per deg. C change in AVR ambient (see note 3)
TYPICAL SYSTEM RESPONSE
AVR response 20 ms
Filed current to 90% 80 ms
Machine Volts to 97% 300 ms
EXTERNAL VOLTAGE ADJUSTMENT
+/-10% with 1 k ohm 1 watt trimmer (see note 4)
Increasing resistance lowers voltage.
UNDER FREQUENCY PROTECTION
Set point 94 -98% Hz (see note 5)
UNIT POWER DISSIPATION
12 watts maximum
BUILD UP VOLTAGE
4 Volts @ AVR terminals
ANALOGUE INPUT
Maximum input +/- 5 Vdc (see note 6)
Sensitivity 1V for 5% Generator Volts (adjustable)
Input resistance 1k ohm
QUADRATURE DROOP INPUT
10 ohms burden
Max. sensitivity: 0.07 A for 5% droop 0PF
Max. input: 0.33 A
OVER EXCITATION PROTECTION
Set point 65 V dc
Time delay 10-15 seconds (fixed)
ENVIRONMENTAL
Vibration 20-100 Hz 50mm/sec
100Hz – 2kHz 3.3g
Operating temperature -40 to +70C (note 7)
Relative Humidity 0-70C 95% (note 8)
Storage temperature -55 to +80C
NOTES
1. De-rate by 12% if mounted in ‘portrait’ orientation.
2. With 4% engine governing.
3. After 2 minutes.
4. Generator de-rate may apply. Check with factory.
5. Factory set, semi-sealed, jumper selectable.
6. Any device connected to the analogue input must be fully
floating (galvanically isolated from ground), with an
insulation strength of 500V ac.
7. De-rate output current by 5% per degree C above 60C.
8. Non condensing.
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