ITT VOGEL L Série Instructions De Montage, De Service Et De Maintenance page 69

Installation, Operating and Maintenance Instruction
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LN 100-ger/fr/eng
Artikel No. 771073301
Cause
Blown fuses
Overload trips
Improper power supply
Improper line connections
Open circuit in winding or control switch
Mechanical failure
Short circuited stator
Poor stator coil connection
Rotor defective
Motor may be overloaded
One phase may be open
Low voltage
Open circuit
Power failure
Voltage too low at motor terminals because of line drop
Starting load too high
Broken rotor bars or loose rotor
Open primary circuit
Low voltage during start
Defective squirrel cage rotor
Applied voltage too low
Wrong sequence of phases
Frame or bracket vents may be clogged with dirt and
prevent proper ventilation of motor
Motor may have one phase open
Grounded coil
Unbalanced terminal voltage
Defective bearings
Balancing weights shifted
Contradiction between balancing of rotor and coupling (half
key - full key)
Polyphase motor running single phase
Excessive end play
Fan rubbing fan cover
Fan striking insulation
Airgap not uniform
■
Rotor unbalance
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■ Bent or sprung shaft
■ Insufficient grease
■ Deterioration of grease or lubricant contaminated
■ Excess lubricant
■ Overloaded bearing
■ Broken ball or rough races
Page 65
What to do
Replace fuses with proper type and rating.
Check and reset overload in starter.
Check to see that power supplied agrees with motor rating
plate and load factor.
Check connections with diagram supplied with motor.
Indicated by humming sound when switch is closed. Check for
loose wiring connections. Also, ensure that all control contacts
are closed.
Check to see if motor and drive turn freely. Check bearings and
lubrication.
Indicated by blown fuses. Motor must be rewound.
Remove end bells, locate with test lamp.
Look for broken bars or end rings.
Reduce load.
Check lines for open phase.
Ensure the rating plate voltage is maintained. Check
connection.
Fuses blown, check overload relay, stator and push buttons.
Check for loose connections to line, fuses and control.
Use higher voltage or transformer terminals or reduce load.
Check connections. Check conductors for proper size.
Check load motor is supposes to carry at start.
Look for cracks near the rings. A new rotor may be required, as
repairs are usually temporary.
Locate fault with testing device and repair.
Check for high resistance.
Adequate wire size.
Replace with new rotor.
Get power company to increase power tap.
Reverse connections at motor or at switchboard.
Open vent holes and check for a continuous stream of air from
the motor.
Check to make sure that all leads are well connected.
Locate and repair.
Check for faulty leads, connections and transformers.
Replace bearings.
Rebalance motor.
Rebalance motor.
Check for open circuit.
Adjust bearing or add shim.
Remove interference.
Clear fan.
Check and correct bracket fits or bearing.
Rebalance.
Straighten or replace shaft.
Maintain proper quality of grease in bearing.
Remove old grease, wash bearings thoroughly in kerosene and
replace with new grease.
Reduce quantity of grease, bearing should not be more than
1/2 filled.
Check alignment, side and end thrust.
Replace bearing, first clean housing thoroughly.
Model L, LN
Revision 02
Issue 10/2006