TROUBLE SHOOTING
32
July 2009 / WHISPER 6/8/11 / US / Copyright © 2009 Mastervolt
5.3.3
Winding resistant values
If after establishing and correcting any fault on the
capacitor and diodes output is still low when separately
excited, then the main rotor, stator and exciter stator
winding resistance should be checked as the fault must be
in one of these windings. The respective leads must be
disconnected before taking the readings.
Resistance values should be within 10% of the values
given in the table below:
Whisper 6 and 8
Resistance
60 Hz
•
Resistance both main stator windings
in series
0.34 Ohm
•
Resistance both rotor windings
0.93 Ohm
•
Resistance exciter stator winding
0.82 Ohm
Whisper 11
Resistance
60 Hz
•
Resistance both main stator windings
in series
0.26 Ohm
•
Resistance both rotor windings
1.05 Ohm
•
Resistance exciter stator winding
0.72 Ohm
5.3.4 Meggering
One can try to measure resistance between the housing
and the windings with a multimeter which should read
infinity. When readings are infinity but a fault is suspected
one can do a high voltage resistance test (MEGGERING)
This procedure should be carried out by an expert
5.4
SPECIAL PROCEDURES ENGINE
5.4.1
Setting the RPM
RPM is set by the manufacturer and should not need
readjustment! However a very slight offset after running in
could occur. RPM can be measured by a frequency meter.
Whisper 8 and 11:
When adjustments are necessary this
can only be done with the help of an interface to a
computer and special software to get access to the
microprocessor. If readjustment of the RPM is necessary,
please contact your Mastervolt Service Centre for advice
Whisper 6:
Before readjustment check any other
explanation for the wrong speed. Engine speed is set at
the factory at nominal 3600 (60 Hz) RPM. A RPM drop of
5% at full load is acceptable. Therefore a no load setting
should be at ± 3750 RPM = 62.5 Hz. Under no
circumstances should the RPM be under full load below
3540 RPM = 59 Hz.
When no cause can be found for a wrong speed, the
setting can be adjusted:
Fig.17
2= adjustment screw RPM
3= manual stop
It is very important to identify the correct setting assembly
(refer to fig. 17).The screw is to be locked in position with
the lock-nut.
1
2
3
