Trouble Shooting; Alternator Malfucntions / Ac Trouble; General; Trouble Shooting Check List Alternator - Mastervolt WHISPER 3,5 User Manual

TROUBLE SHOOTING

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 to start.

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.
5.1.2 Trouble shooting table
PROBLEM
No output (Voltage) at all.
Generator output voltage too
low when no load is on it
(less than 105V).
Generator output voltage too
low under load (less than 105V).
In no load condition it is ok.
Generator voltage too high,
(more than 130V).
Generator voltage fluctuates.
22
CAUSE
• Circuit breaker "off" or faulty fuse
• Low engine RPM.
• Loss of residual magnetism.
• Capacitor loose or broken.
• Rotor diodes broken.
• No load at all or very low load.
• Engine is not reaching the rated RPM.
• Defective capacitor.
• Defective diode (one of the two)
• Generator is overloaded.
• Engine is not reaching the rated RPM.
• Defective capacitor.
• Engine is running too fast (RPM too high).
• Over-energising due to defective
capacitors.
• Presence of a strong capacative load
(leading power factor).
• Disturbances on the electrical system/
user side.
• Engine runs irregularly.
If in doubt measure directly on the alternator terminals
with an independent instrument.
This should only be carried out by an experienced electri-
cian.
Check if the engine is running correctly at 3600 (60 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 3750 RPM = 62.5 Hz.
Under no circumstances should the RPM under full load
be below 3540 = 59 Hz.
When the problem is in the RPM refer to the engine fault
finding paragraph.
Digital Diesel Control systemwill help to indicate failures
and display causes.
SOLUTION
Check switches and fuses and measure direct-
ly on the alternator to exclude external causes.
Check the engine RPM and adjust (refer to
special procedures).
Check the residual magnetism and flash the
alternator (refer to special procedures).
Check by independent excitation if the problem is
in the capacitor or in the windings.
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.
Switch on a load and check voltage.
Refer to special procedures to readjust RPM.
Check capacitor and replace if necessary (refer
to special procedures).
Check the diodes in the rotor and replace (refer to
special procedures).
Switch off a load; (part off ) consumers.
Refer to engine RPM problems.
Check capacitor and replace if necessary (refer
to special procedures).
Check engine speed and adjust (refer to special
procedures).
Check capacitor specification and replace if
necessary.
Compensate for this capacity and seek for experts
advice.
Check if electrical load is fluctuating.
When engine runs irregularly refer to section:
"Engine runs irregularly".
April 2004 / WHISPER 3,5 / USA