Technical information

TROUBLE SHOOTING
26 Copyright © 2009 Mastervolt / December 2009 / WHISPER 3.5 / EN
5.1.3 Other electrical problems
Problem Possible cause What to do?
• 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.
• Disturbances on the electrical system/ user
side.
Check if electrical load is fluctuating Generator voltage
fluctuates.
• Engine runs irregularly.
When engine runs irregularly refer to section:
"Engine runs irregularly".
Generator is not able
to start an electric
motor
If the generator is unable to supply enough
power to start an electric motor (230V), this
is usually because this motor draws too
much current during starting
Check the electric motor’s current draw required
for starting. This should not exceed 70% of the
rated generator output current. This could be
remedied by providing stronger capacitors to the
motor or using a "soft-start". Inquire at your
nearest Mastervolt dealer or directly at the
manufacturer, Mastervolt in the Netherlands.