TROUBLE SHOOTING
EN / M-SQ20 / 25 / November 2010
27
5 TROUBLE
SHOOTING
5.1
Alternator/ electrical faults
CAUTION!
Remove 3 Amp. Fuse in the control panel
while working on the generator to prevent the
engine to start
DANGER!
Take care for parts which are live!
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. 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 manualof
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 3% at full load is acceptable. Therefore a
no load setting should be at 1545 RPM = 51.5 Hz. Under
no circumstances should the RPM under full load be below
1485 RPM = 49.5 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.
CAUTION!
If the voltage is set any higher than its
maximum limit, the generator may be
damaged.
If the bottom speed is set at too low a frequency, the
generator may be damaged. On the other hand too high a
frequency can cause voltage drops with high loads.
A failure code is displayed when a hardware failure at the
generator is detected.
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
EXHAUST TEMP
Exhaust temperature is too high
WATER TEMP
Coolant temperature is too high
OIL PRESSURE
Oil pressure failure
LOW VOLTAGE
Generator AC output voltage is too low
HIGH CURRENT
Generator is in overload
FREQUENCY
Output frequency of the generator is too low
5.1.2
Trouble shooting table
PROBLEM CAUSE
SOLUTION
No output (Voltage) at all
•
Circuit breaker "off" or faulty main fuse
•
Faulty fuse of the AVR
Check switches and fuses and measure
directly on the alternator to exclude external
causes. 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 (see 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).