TROUBLE SHOOTING
22
May 2006
/ WHISPER 3,5 / EN
5 TROUBLE
SHOOTING
5.1
ALTERNATOR/ ELECTRICAL FAULTS
Beware of parts which are live!
Remove 3 Amp. Fuse in the control panel
while working on the generator to prevent the
engine from starting
5.1.1 General
If any problem should occur, check basic conditions and
examine all external wiring, switch gear and circuit
breakers. Also check if measuring instruments give the
correct value. If in doubt, measure directly on the
alternator terminals with an independent instrument.
This should only be carried out by an experienced
electrician.
Check if the engine is running correctly at 3000 (50 Hz)
RPM according to its settings and does as well under load.
A RPM drop of 5% at full load is acceptable. There-fore a
no load setting should be at 3150 RPM = 52.5 Hz or 3750
RPM = 62.5 Hz. Under no circumstances should the RPM
under full load be below 2940 RPM = 49 Hz or 3540 = 59
Hz.
When the problem is in the RPM refer to the engine fault
finding paragraph.
Digital Diesel Control system will help to indicate failures
and display causes.
5.1.2
Trouble shooting table
PROBLEM CAUSE
SOLUTION
•
Circuit breaker "off" or faulty fuse
Check switches and fuses and measure
directly on the alternator to exclude external
causes.
•
Low engine RPM.
Check the engine RPM and adjust (refer to
special procedures).
•
Loss of residual magnetism.
Check the residual magnetism and flash the
alternator (refer to special procedures).
•
Capacitor loose or broken.
Check by independent excitation if the problem
is in the capacitor or in the windings.
No output (Voltage) at all
•
Rotor diodes broken.
Check the diodes in the rotor (refer to special
procedures) The Whisper 3,5 has two diodes
in the rotor. It happens very rarely that both
are broken. When only one diode is broken the
voltage will be low but will not varnish
completely.
•
No load at all or very low load.
Switch on a load and check voltage.
•
Engine is not reaching the rated RPM.
Refer to special procedures to readjust RPM.
•
Defective capacitor.
Check capacitor and replace if necessary
(refer to special procedures).
Generator output voltage too
low when no load is on it (less
than 210V).
•
Defective diode (one of the two)
Check the diodes in the rotor and replace
(refer to special procedures).
•
Generator is overloaded.
Switch off a load; (part off) consumers.
•
Engine is not reaching the rated RPM.
Refer to engine RPM problems
Generator output voltage too
low under load (less than 210V).
In no load condition it is ok
•
Defective capacitor
Check capacitor and replace if necessary
(refer to special procedures).
•
Engine is running too fast (RPM too
high).
Check engine speed and adjust (refer to
special (more than 245V).procedures).
•
Over-energising due to defective
capacitors
Check capacitor specification and replace
capacitors if necessary.
Generator voltage too high,
(more than 245V)
•
Presence of a strong capacitive load
(leading power factor)
Compensate for this capacity and seek for
experts advice.