Introduction
Types
of motors; Equivalent circuits; Speed - Torque characteristics; DOL,
Star-Delta; Temperature rise and
duty cycle ( type S1 to S6), Degree of protection.
Protection
HT
Motors - Thermal, Stalling, Instantaneous, Negative sequence and Ground
fault protection.
LT
Motors - Bimetal, Fuse; Setting of Bimetal; Fuse - Relay co-ordination
problem.
Testing
Routine
maintenance test; Winding resistance, IR, PI, Dielectric Absorption, High-
Pot; tan d.
Condition
Monitoring
IR,
PI, Thermo graphic, Vibration analysis
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