TROUBLE SHOOTING
EN / W-SQ20 for mobile applications / April 2010
27
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
A failure code is displayed when a hardware failure at the
generator is detected
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.
These measurements should only be carried out by an
experienced electrician
If during these measurements the engine immediately
stops after starting and an error code is displayed at the
remote control panel ( “AC VOLTAGE”), one can start the
generator by means of a “service start” at the service
menu (see paragraph “service start” of the user’s manual
of the Digital Diesel Control). By doing this, the generator
will keep running for 2 minutes before it stops. This offers
you the possibility to carry out measurements to
investigate the cause of the failure.
Check if the engine is running correctly at 1500 RPM (50
Hz) according to its settings and does as well under load.
A RPM drop of 5% at full load is acceptable. Therefore a
no load setting should be at 1575 RPM = 52.5 Hz. Under
no circumstances should the RPM under full load be below
1470 RPM = 49 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.
Failure code
Problem
COMMUNICATION
Communication error between the panel end the generator
LOW START BAT
Starter battery voltage too low
ALTERNATOR
No output battery charging voltage
AC-ALTERN. TEMP
AC-alternator temperature is too high
WATER TEMP
Coolant temperature is too high
OIL PRESSURE
Oil pressure failure
AC VOLTAGE
Generator AC output voltage is either too high or too low
HIGH CURRENT
Generator is in overload
FREQUENCY
Output frequency of the generator is too low
5.1.2
Trouble shooting table alternator
PROBLEM CAUSE
SOLUTION
No output (Voltage) at all
•
Circuit breaker "off" or faulty main fuse
Check switches and fuses and measure
directly on the alternator to exclude external
causes.
•
Faulty fuse of the AVR
Check fuse of the AVR
•
Loss of residual magnetism.
Check the residual magnetism, temporally
increase RPM with 15%. Try to and flash the
alternator (see special procedures)
•
Low engine RPM.
Check the engine RPM and adjust (refer to
special procedures).
•
Faulty RPM.
Check by independent excitation if the problem
is in the AVR or in the windings and replace if
necessary (see special procedures).
•
Rotor diode broken.
Check the diode in the rotor (see special
procedures). The W-SQ20 has one diode
block/rectifier unit.
Generator output voltage too
low when no load is on it (less
•
Engine is not reaching the rated RPM.
See special procedures to readjust RPM.
