ABB M3JM Betriebsanleitung Seite 24

TROUBLE CAUSE
Motor takes too long Excessive load
to accelerate and/or
Low voltage during start
draws high current
Defective squirrel cage rotor
Applied voltage too low
Wrong rotation Wrong sequence of phases
direction
Motor overheats Overload
while running
Frame or ventilation openings may
be full of dirt and prevent proper
ventilation of motor
Motor may have one phase open
Grounded coil
Unbalanced terminal voltage
Motor vibrates Motor misaligned
Weak support
Coupling out of balance
Driven equipment unbalanced
Defective bearings
Bearings not in line
Balancing weights shifted
Contradiction between balancing
of rotor and coupling (half key – full
key)
Poly-phase motor running single
phase
Excessive end play
Scraping noise Fan rubbing end shield or fan cover
Loose on bedplate
Noisy operation Air gap not uniform
Rotor unbalance
WHAT TO DO
Reduce load.
Check for high resistance. Make sure that an adequate
cable size is used.
Replace with a new rotor.
Correct power supply.
Reverse connections at motor or at switchboard.
Reduce load.
Open vent holes and check for a continuous stream of
air from the motor.
Check that all leads and cables are well connected.
Motor must be rewound.
Check for faulty leads, connections and transformers.
Realign.
Strengthen base.
Balance coupling.
Rebalance driven equipment.
Replace bearings.
Repair motor.
Rebalance rotor.
Rebalance coupling or rotor.
Check for open circuit.
Adjust bearing or add shim.
Correct fan mounting.
Tighten holding bolts.
Check and correct end shield fits or bearing fits.
Rebalance rotor.
3GZF500730-47 rev E 06-2015 | ABB Motors and Generators ML/EN – 23