Engine; Digital Diesel Control System; Battery Charger; Alarms And Shut Down - Whisper Power m-sq25 User Manual

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 burden on the engine.
Further technical data on the design of the alternator can
be found in drawings and diagrams in this manual.
EN / M-SQ20 / 25 / November 2010
delta arrangement is
2.5.2

Engine

The M-SQ20 / 25 generating set is based on the
Mitsubishi S4S 4 cylinder 4 stroke diesel engine. The
engine is indirectly injected. The engine is water cooled
and the cooling liquid is cooled by a heat exchanger and
raw (sea) water. The heat exchanger and all other parts
which are in direct contact with the raw (sea) water are
made of seawater resistant material like naval brass and
copper nickel.
The engine has been
WhisperPower application and is very different from the
standard engine supplied for industrial applications!
2.5.3

Digital Diesel Control system

The standard electrical engine control system is 12 Volt
negative earth, non earth return (ungrounded) is available
as optional. Check your identification data to determine
which system is applied. The system is designed
according to the "energise to run" system. The Digital
Diesel Control is a very advanced microprocessor based
full automatic system. Besides automatic start the system
offers many monitoring options. See the separate Digital
Diesel Control users manual (number 50200261).
The microprocessor unit of the Digital Diesel Control is
located in the black box on top of the AC alternator (see
figure 5).
2.5.4

Battery charger

On the engine is an alternator generating 50 Amp 12V.
This current is rectified to charge the battery. The voltage
is regulated at approx. 14.4V.
2.5.5

Alarms and shut down

In case of malfunctioning this will be indicated by the
failure light, details will be shown on the display and the
engine will be shut down. There are three functions
guarded: oil pressure, oil temperature and exhaust
temperature.
Exhaust temperature too high indicates the cooling water
to be blocked.
All alarm switches are closed when no malfunction occurs.
A contact is cut in the event of an alarm. This means that
the generating set will not work when the alarm switches
are broken or there is a loose wire. The system therefore
is intrinsically safe. The panel will display details about the
alarm.
2.5.6

Monitoring

Refer to the operating of the Digital Diesel Control
INFORMATION
specially adapted for
13
the