CAMTECH/97/E/TM/3.0
TM Maintenance Handbook January’97
31
SN
FAILURE/ TROUBLE
POSSIBLE CAUSES AND REMEDIES
COMMUTATOR
i) High bar, Low bar, Deformation, Ovality : Colour
change, unequal oxygenated film, abnormal wear of
brush may be caused a flash over. Polish the commu-
tator surface with lathe.
ii) Joggle wear and roughening of surface : Polish commu-
tator surface with lathe.
iii) Bad chamfering / under cutting : Reform with lathe.
iv) Shorting the bars by dust and foreigner between bars :
Inspect and clean the commutator bars with petrol.
v) Abnormal temperature rise : Examine ventilation and
load and adjust.
vi) Black bar : Adjust commutation.
vii) Vibration : Examine radial as well as lateral clearances
of bearing , vibration of Bogie frame, unbalancing of
armature.
2
OVERHEAT
BEARINGS
i) Bruise, scratch, rust : Replace it with a new one.
ii) Improper quality of grease : Replace with new and
proper grade of grease.
iii) Improper fitting or clearances : Check fitment and clear-
ances and replace it with new and good bearing, if re-
quired.
COILS
i) Layer short, insulation breakdown: Find failure part and
repair it.
