INFORMATION
12
January 2009 / W-SQ25 for mobile applications / EN
2.4.2
Generator control panel
Start / Stop
Remove fuse
Internal fuel pump
Fuse 3A
before maintenance
Digital Diesel Control
Fuse 3A
Auxiliary
Fuse 10A
External Fuel Pump
Fuse 3A
Observe instructions in the manual
Replace fuses with same type and rating
Whisper Digital Diesel Operation Unit
Fig: 8 Control panel.
Fig. 9 Digital Diesel Control unit
2.4.3
Remote control panel
04
03
02
01
05
07
06
01
Generator load indicator
02
Failure LED
03
Start button
04
Stop button
05
Display
06
Select button
07
Set button
Fig. 10: Digital Diesel remote control panel
2.5
TECHNICAL INFORMATION
2.5.1
AC alternator
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).
The exciter stator has a residual magnetism, which
guarantees self-exciting of the generator on start-up (that
thereby generates a residual voltage of about 10%
nominal voltage).
The AVR, powered by an auxiliary circuit on the main
stator, acts on the exciter stator indirectly controlling the
field generated by the main rotor by means of the
sequence exciter rotor - diode bridge - main rotor.
The voltage regulator controls and keeps constant the
average voltage of one phase. The voltage setting on the
AVR can be adjusted with the help of a trimmer “V”
between 185 and 290 Volts. (See par. 5.3.1)
A frequency control progressively deactivates the machine
when the drive motor speed drops below a pre-set,
adjustable threshold preventing over-excitement at low
operating speeds and abating the load engage effects on
the engine.
The AVR works only within limits of the set frequency 50
Hz. When operating below the lower limit of 46 Hz ± 1 Hz
the AVR will stop regulating to avoid overloading the
exciter coil (This setting can be changed with trimmer
“UF”). (See par. 5.3.1)
When applying the generator set at 60 Hz the AVR is re-
adjustable as well. To operate at 60 Hz the engine RPM
and Digital Diesel Control settings must also be changed.
For the USA market a dedicated manual (Art. No
50200444) is available for 60 Hz applications. Please refer
to the
Whisper Power
centre for specific instructions to
convert the generating set to 60 Hz.
A further option is to readjust the stability of the regulator.
In the event of very irregular (alternating) loads it could be
necessary to change this setting with the help of trimmer
“S” to avoid interference of the regulator and the
alternating load. In conclusion the regulator reaction time
can be modulated to eliminate any voltage instability that
may arise. (See par.5.3.1)
Fig. 11 Automatic Voltage Regulator (AVR).
