Motor Troubleshooting Chart - Siemens 1SE0 Operating And Maintenance Manual

IS: 7816: Guide for testing insulation
resistance of rotating machines.
IS: 9628: Specification for Three phase
induction motors with type of protection
'n'.
IS: 6381: Specification for construction and
testing of apparatus with type of protection
'e'.
IS: 12065: Permissible limits of noise level
for rotating electrical machines.
7.

Motor Troubleshooting Chart

Sr.
Trouble
No.
1 Hot bearings
2 Motor connected but
does not start
3 Motor runs & then stops
down
16
IS: 12075: Mechanical vibration of rotating
electrical machines with shaft heights
56mm and higher – Measurement,
Evaluation and Limits of Vibration severity.
IS/IEC: 60034-1: Rotating electrical
machines – Part 1: Rating and
Performance.
IS/IEC: 60034-5: Degree of protection for
rotating electrical machines.
EN: 60204: Safety of machinery –Electrical
equipment of machines.
Cause
Excessive belt pull
Pulley too far away
Pulley dia. too small
Misalignment
Broken ball or rough races
Excess lubricant
Overloaded bearings
Bearing running dry
No supply voltage/ One
phase open/ Voltage too low
Motor may be overloaded
Control gear defective
Starting torque too high
Rotor defective
Short circuit to earth
Fault in starter or star/delta
switch
Power failure
Over load
Remedy
Decrease belt tension.
Move pulley closer to bearing.
Use larger pulley.
Correct by realignment of drive.
Replace bearings.
Reduce quantity of grease
(Bearing should be filled only half).
Check alignment, side thrust & end thrust.
Regrease the bearing.
Check voltage on each phase.
Reduce load or start at no load.
Examine each step of the control gear for
bad contacts or open circuit.
If with autotransformer starting, change to
higher tap.
Look for broken rings.
Check with Megger.
Check contacts & connections.
Check for loose connections to line, fuses &
control gear.
Examine overload trips & see that they are
set at approx. 150% of full load current.