Whisper Power M-SQ27 User Manual page 13

Fig. 11: Automatic Voltage Regulator (AVR)
Fig. 12: AVR Trimmers (potentiometers)
The power comes from 12 wires that can be connected in
star, delta or combined double / star and double / delta
arrangements to take off different voltages. For tri phase
400V use, the alternator should be connected in star. For
single voltage 230V use the wires should be connected in
double delta. The alternator is specially designed that in this
way one can take off the full power off the generator.
However the use of three groups of 230 V taken from the
three corners of a single
recommended. Other voltages (115 Volt) can be arranged
as well. Further technical data on the connections of the
alternator can be found in drawings and diagrams in this
manual.
The tri phase synchronous alternator is directly coupled,
one bearing, brushless, rotating field design, 12 wire, four
pole (1500 RPM) and regulated by an Automatic Voltage
Regulator (AVR).
Residual magnetism causes a small voltage over the stator
windings and allows a current to flow in the windings, which
is magnified because of the feedback effect between rotor
and stator. The field windings in the rotor are short-circuited
over a diode to rectify the current. A capacitor over an
additional winding in the stator which is at an angle with the
power winding keeps the voltage stable within 5 % at the
specified rpm and provides voltage fall off with speed,
preventing over-excitation at low engine speeds and
softening the effect of load switching to relieve the load on
the engine.
EN / M-SQ 27 / August 2020
delta arrangement is
Further technical data on the design of the alternator can be
found in drawings and diagrams in this manual.
INFORMATION
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