Faults - Causes And Solutions - ITT MPB Series Einbau-, Betriebs-, Wartungshandbuch

Installation, Operating and Maintenance Instruction
The life span of the deep groove ball bearings is appr.
17500 hours of operation.
12.6.3 Bearing dimensions of the motors
frame size
DPIG 56
DPIG 63
DPIH 71
DPIH 80
DPIH 90
IMB3
DPIH 90
IMV1
DPIG 100
IMB3
DPIG 100
IMV1
DPIG 112
DPIG 132
DPIG 160
DPIG 180
DPIG 200
DPIG 225
MPB 100-english
Article No 771074115
bearing type
6201 ZZ
6202 2RS
6203 2RS
6204 2RS
6205 ZZ C3
6205 ZZ C3
6305 ZZ C3
6206 ZZ C3
6206 ZZ C3
6306 ZZ C3
6306 ZZ C3
6308 ZZ C3
6309 ZZ C3
6311 ZZ C3
6212 ZZ C3
6213 ZZ C3
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
page 103
12.6.4 Spare parts
When ordering spare parts, the full type designation
and product code as stated on the rating plate must be
specified.
If the machine is stamped with a serial manufacturing
number, this should also be given.
12.6.5 Rewinding
Rewinding should always be carried out by qualified
repair shops.

12.7 Faults - Causes and Solutions

The following procedure cannot list all technical details
or differences between the different motor models or
all possible happening situations at the installation, the
operation or at the maintenance.
Maintenance and elimination of errors on the motor
must be performed by qualified persons and with
qualified tools/instruments and resources.
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.
Model MPB, MPV
Revision 01
Issue 12/2006