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EA440 3
3.2 Stability Adjustment
If a replacement AVR has been fitted or re-setting of
the stability control is required, turn the stability
trimmer slowly clockwise until the output voltage is
steady, on or off load.
3.3 Droop Adjustment
Generator intended for parallel are fitted with a
quadrature droop CT with provides a power factor
dependent signal for the AVR.The CT is connected to
S1, S2 on the AVR. The Droop adjustment is normally
present in the works to give 5% voltage droop at full
load zero power factor. Clockwise increases the
amount of CT signal injected into the AVR and
increases the droop with lagging power factor. With
the control fullyanticlockwise there is no droop.
3.4 Trim Adjustment
An auxiliary input is provided to connect to A1, A2. It
is designed to accept DC ± 5V.Turn the TRIM
trimmer fully anticlockwise has no effect, Clockwise
it has maximum effect.
4. FIELD FLASHING
When the regulator is operated with the generator
for the first time, the polarity of residual magnetism
may be reversed or too small to achieve the
necessary build-up voltage for the regulator. If
reversing the field connections does not induce
build-up, and the residual voltage is less than the
specified value of 5 VAC, shut down the
Prime-mover and proceed with the following steps :
1. With the Prime-mover at rest and the regulator’s
field output wires disconnected, apply a DC
source ( NOT grounded ) of no more than 3~12
VDC with Positive to X and Negative to XX, in
series with a current-limiting resistor of 3~5 ohms
20 watt. (The set battery is a suitable source.)
2. Allow approximately 3 seconds before removing
the DC source.
3. Disconnect the AVR AC power input terminals
and restart the generator, re-measure the
residual voltage. If this voltage is greater than
5VAC, reconnect voltage regulator, and voltage
build-up should be successful. If measured less
than 5VAC, repeat steps 1 and 2.
4. If residual voltage is greater than 5VAC, but AVR
still unable to build up voltage, please replace
with another AVR.
WARNING
Overly field flashing may damage the AVR or
generator excitation winding.
Please make sure you have read and
understand the contents of the instruction
manual prior to installation. Incorrect wiring
connection may result in irreversible damage
to the product and other equipments.
5. PARALLEL FUNCTION
5.1 Parallel Compensation
1. When it is required to operate the regulator in
parallel with an isolated or utility bus, in addition
to the regulator provisions, a 10VA current
transformer (CT) is required ( See Figure 3 ). The
CT is connected in a generator line and should
deliver from 1 amperes secondary current at
rated load.
2. The phase relationship of CT signal to the
regulator sensing voltage must be correct or the
system will not parallel properly. The CT must be
installed in the line of the three phase generator
that does not supply sensing to the regulator.
5.2 Reactive Droop Compensation
1. For reactive droop compensation, connect the
CT to it’s respective regulator as shown on
Figures 3.
2. A unit-parallel switch shorts the parallel CT
secondary to prevent any droop signal from
being injected into the regulating system during
single unit operation. The switch may not be
required on parallel droop compensation
applications where a voltage drop is not
objectionable.
