
MEP 660 - Trouble shooting Manual
Doc No.: IM – 51
Rev.2.0
Print: October 2008
154
PARAMETER
DESCRIPTION
FAULT CODE
1143
FAULT MESSAGE Aux. Gen. Output 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. output current is reduced.
Automatic fault reset is permitted for 3 times in an Hour. After that
manual reset is required.
PROBABLE
CAUSES
1. There may be a real high current due to short circuited load
2. Defective Aux. Generator due to direct short of field wire with
Armature.
3. Defective AGAI current sensor
4. Defective Aux. Gen. Voltage sensor.
5. Defective MAIP8_AU card (Analog input card of Aux. Unit) in slot 1
6. Defective MAUCC card (Aux. Unit Control card) in slot No. 3
FAULT
ISOLATION
If the fault is logged soon after cranking, then it may due to deep
discharge. The message may be ignored.
1. Set the display mode to ‘Auxiliary’ under ‘Display’ menu option.
2. If (AGAV) Aux. Gen Voltage is high but the AGFI is zero or normal:
A. Defective Aux. Gen. with a field short-circuited internally with
the armature.
B. ‘Aux. Gen Voltage High’ message will be logged.
3. If Battery charging current is high but AGAV voltage is normal:
A. It may be due to defective battery set. Check individual battery
voltage and specific gravity value and level. Replace the
defective battery. However the ‘Battery charging current High’
message will also be logged.
4. Measure and compare the Current flowing from Aux. Gen. with a
clamp on ammeter.
A. If both AGAI value on the display and clamp on ammeter are
same ad high, then there is a real over load. Identify and
rectify.
B. If the AGAI value is comparatively higher than the clamp on
ammeter, then AGAI is defective. Replace the sensor and check
again.
C. If both AGAI value and clamp on ammeter value are same and
the values are with in the set limit of AGAI and still the fault is
logged then the MAIP8_AU or MAUCC cards are defective.
Replace the cards and check again.