
MEP 660 - Trouble shooting Manual
Doc No.: IM – 51
Rev.2.0
Print: October 2008
155
PARAMETER
DESCRIPTION
FAULT CODE
1144
FAULT MESSAGE Aux. Gen. Field Over Current FAULT
RESTRICTIONS
Battery charging
ALARM BELL
5 Sec.
RESET LEVEL
Medium, Manual
After manual reset if the fault still present, the fault will be generated
again.
FAULT
RECOVERY
Automatic when Aux. Gen. field current is reduced.
Automatic fault reset is permitted for 3 times in an Hour. After that
manual reset is required.
PROBABLE
CAUSES
1. External short circuit between AGC wire and 4 wire.
2. Defective MPWM2 card.
3. Defective (AGAV) Aux. Gen. Voltage sensor.
FAULT
ISOLATION
1. Set the display mode to ‘Auxiliary’ under ‘Display Mode’ menu.
2. Switch OFF AGFB breaker and Crank the engine.
3. On the display APWM value should be zero.
4. If AGFI is abnormally high, remove MPWM2 card from slot 18.
A. If AGFI is still showing high, there could be an external short
circuit bypassing PWM o/p (AGF) or the Aux. Gen. is defective.
a) Check up the short-circuited wires and replace. If necessary
replace the Aux. Gen.
B. If AGFI is zero after removing MPWM2 card, the MPWM2 card is
defective. Replace and check up.
5. Switch ON AGFB. APWM and AGFI should rise slowly.
6. If the fault still logged, check the Aux. Gen. Voltage AGAV.
7. If AGAV is zero, measure the Aux. Gen. Voltage with a voltmeter at
the Aux. Gen. terminals.
A. If the Voltage is zero, there is an open circuit in the machine. A
fault message ‘Auxiliary Generator Output Circuit Open FAULT’
will also be logged. Check up with the machine.
8. If the voltage at Aux. Gen. Terminals is 72V, measure the voltage
at AGAV voltage sensor input terminals.
A. If the voltage is zero, the wiring from Ax. Gen. To AGAV voltage
sensor is defective. Identify the open circuited leads and
replace.
9. If the voltage at AGAV sensor terminals is 72V and AGAV is
showing zero, the AGAV sensor is defective.
A. Replace the AGAV sensor and check up.