Rd2 Avr Settings; Wiring Diagrams For Different Circuits - Sincro SK225 SM Manuel D'utilisation Et De Maintenance

6.4.5 RD2 AVR
The AVR controls the generator voltage. The AVR is
used to keep a constant voltage when the load and
machine parameters vary. The AVR requires a so-called
sensing connection; a power supply from a specific
circuit (AUX); an output to the exciter (+/-).
The RD2 board is a digital controller that allows you to
select the three-phase sensing (the regulator will keep
constant the average of the 3 voltages detected) or
single-phase sensing. The selection is made by dip-
switch.
In case of unbalanced or distorted load, voltage
regulation accuracy could be reduced.
A frequency control progressively reduces the generator
excitation when the drive engine speed drops below a
pre-set, adjustable threshold preventing over-excitation
at low operating speeds and abating the load engage
effects on the engine.
In conclusion the regulator reaction time can be
modulated to eliminate any voltage instability that may
arise.
The regulator has a dip-switch for the selection of the
working frequency. Set the dip switch (50 / 60Hz) of
the AVR board, depending on the operating frequency
(50Hz ON, 60Hz OFF).
Voltage setting: first, select the type of sensing (three-
phase or single-phase) through the dip-switch. Then
turn, moving it to the ON position, the dip-switch that
shows the voltage closest to the desired value (which
must be consistent with the connection made).
Turn ON the dip-switch:
• "115" if connected to a sensing
and 130V
• "230" if connected to a sensing
and 245V.
• "400" if connected to a sensing
and 460V.
• "480" if connected to a sensing
and 520V.
The output voltage can be changed by adjusting
potentiometer "V". Run the generating set to its nominal
speed and turn until the required voltage is obtained.
If a small variation in speed causes a change in
voltage, then the under speed protection should first be
calibrated.
If the voltage is set any higher than its
maximum limit the gen er a tor may be
damaged.
WARNING!
Stability adjustment: if on load voltage fluctuations
are experienced adjust potentiometer "ST", which
modulates the reaction time of the regulator to external
inputs, there by eliminating any instability in the
alternator-load system.
If the adjustment via potentiometer ST does not prove
to be sufficient, is possible also to use the dip-switch
ST+ / ST: moving it to the ON position (ST +) stability
increases.
If the under speed is set at too low a
frequency, the generator may be damaged.
On the other hand, too high a frequency can
cause voltage drops with high loads.
WARNING!
26
Setting of the under speed protection at 50 (60)
Hz: start up rotation of the gen er at ing set adjusting it to
obtain a frequency of 46 (56)Hz. Turn trimmer "UF" until
the voltage begins to drop. Restore nominal speed.
Remote voltages adjustment :
1) with potentiometer:
POT (and make sure the dip switches EXT-VOLT is
turned OFF).
Wire the potentiometer (5kOhm, 3W) to the terminals
"EXT POT". Run the generating set to its nominal speed
and adjust the external
obtain the desired voltage. The external potentiometer
has the effect of increasing the voltage value set by the
"V" trimmer.
2) Connection with controller or cosf regulator:
ON the dip-switch EXT-VOLT (and make sure the dip
switches EXT-POT is turned OFF).
accepts voltage analogic input (0-10VDC, observe
polarity shown in figure) for remote voltage adjustment.
To set the system, follow this procedure:
- Decrease the voltage by turning the "V" trimmer
counter-clockwise;
- Apply half the control voltage at the "EXT pot" terminals
(5 VDC);
- Act on the "V" trimmer to bring the voltage to the
nominal value;
in this way, the external controller can increase or
decrease the output voltage.
In case the remote voltage adjustment is not used, turn
OFF the dip-switches EXT-POT and EXT-VOLT. Pay
attention not to turn ON both the dip-switches.
voltage between 100
voltage between 185
voltage between 340
voltage between 440

6.4.6 Wiring diagrams for different circuits

In the appendix of this manual there are diagrams for
connections other than the factory star-series connec-
tion (standard unless otherwise specifi ed on order).
Turn ON the dip-switch EXT-
potentiometer and trimmer "V" to
Frequency Voltage
Phase
Dip-switch Dip-switch Dip-switch
Voltage
increasing
Voltage
decreasing
Underfrequency
Connection with controller,
protection limit
Observe polarity:
increasing
Underfrequency
protection limit
decreasing
Turn
The AVR regulator
Stability
decreasing
Stability
increasing