ac motor mfg_ trouble shooting

7/31/2019 AC Motor Mfg_ Trouble Shooting

1/9

PROCESS CONTROL CHART OF 3 PHASE ROTOR MANUFACTURE (At CLW)

Rotor ShaftMachining

Rotor

Stacking withDummy Shaft

Oven heating

160 C

Oven heating160 C

Rotor Copper

Stamping

Oven heating

160 C

Placement of

Dummy stack

in Shaft under300T press

Rotor bar

insertion for

Induction braze

Rotor bar inse-

rtion for MIG

Rotor bar

insertion for

Copper

stamping

Brazing of

Copperstamping with

Rotor Bar

V groove

machining in

Resistance ring

Face machining

Final machining

MIG welding

Induction

brazing

Shrink ring

fitment

Primer & Top

coating Painting

Inner Labyrinth

fitment & dist-

ance maintain

machining

Bearing inner

race fitment Rotor balancingInspection

Despatch for

Motor Assly


2/9

PROCESS CONTROL CHART OF 3 PHASE STATOR MANUFACTURE (AT CLW)

Stator

Stacking

Stator tack

welding

under 70T

Press

Stator Welding

& Machining at

HMS (Shop 08)

Stator slot

regularization

& Oven

heating

Primer

Painting

Stator Winding,

Connection &

Brazing

Stator Coil

formingSpreading Insulation Moulding Testing

Testing

V.P.I. of

Stator

Baking in

OvenInspection

Despatch

for

Motor

Assly.


3/9

PROCESS CONTROL CHART OF 3 PHASE MOTOR MANUFACTURE

Stator RotorEnd Frame

(DE)

End Frame

(NDE)

Motor

Assembly

Dummy Pinion

Extraction &

Pinion Fitment

Final Inspection

& Testing

Despatch to

Bogie Shop


4/9

Troubleshooting Chart

Symptom Possible fault Means of checking Remedy Notes

Earth fault signal Connecting lead

damaged with earth

fault

Check the connecting

lead

Renew the lead Check route of lead

for sharp edges and

chafing points

Winding insulation

damaged

Check insulation

resistances

Repair after

consulting

manufacturer

Determine the causes

of the damage:

foreign bodies in the

motor

Impermissible

winding

temperature of a

single motor

For self-ventilated motors only

Fan is loose Check seat through the

exhaust opening

Secure the fan

Fan deformed or

broken

Visual inspection

through the exhaust

opening

Renew the fan Determine

consequential

damage (e.g. stator

winding damaged)

Cooling ducts

blocked in motor

Clean the ducts

Impermissible

winding

temperature of all

the motors

Overloading Reduce the load,

localise any

blockages and

clear them

Temperature

indication isunrealistic of

defective

Resistance

temperature detectoris defective

Renew the

resistancetemperature

detector

Connection terminal

loose

Open the terminal

connection box and

check the terminals

Tighten terminal

with required

tightening torque

and, where

necessary, renew

the cable lug

Check for damaged

thread

Local overheating Winding insulation

damaged

Check the winding

resistances, check the

insulation resistances,

measure the impedance

Repair after

consulting

manufacturer


of the damage:

Foreign bodies in the

motor, parts of rotor

in motorBearing fouled Remove the bearing

cover

Renew the

bearing, regrease

at the N-end only

Check the bearing

seal and renew,

where necessary

Wrong bearing

clearance

Lift the shaft and

measure play with a

dial gauge

Install a bearing

with the correct

clearance, check

seating

Determine causes of

change in bearing

clearance


5/9

Symptom Possible fault Means of checking Remedy NotesBearing damage Remove the bearing

cover

Consult the

manufacturer

Determine

consequential

damage:

fragments in motor,

rotor core assembly

touches the stator

core assembly

Bearing seized Remove the bearing

cover, bearing

discoloured or

deformed, bearing

cover deformed

Consult the

manufacturer

Determine causes of

seizing, failure of

lubrication, excessive

loading

Bearing over or

underlubricated

Lubricate bearing

correctly

Reduced bearing

service life

Cooling ductsblocked in motor Clean coolingducts

Smoke development Winding insulation

damaged

Check the winding




Repair after

consulting

manufacturer


of the damage:


motor, parts of rotor

in motor, overcurrent

Bearing seized Bearing cover

discoloured, bearing

discoloured or

deformed

Remove the

bearing, consult

the manufacturer

Determine causes of

seizing, failure of

lubrication, excessive

loading

Shaft bent can be determined only

after dismantling

Consult the

manufacturer

Determine the cause,

localise

consequentialdamage:

Stator / rotor core

assembly, stator

winding, shaft

attachments

(e.g. transmitter

wheel for speed

controller)

Scorching smell Lead damaged or

interrupted

Check the connecting

lead

Renew the lead Check route of lead

for sharp edges and

chafing points

Connection terminal

loose

Check the winding




Repair after

consulting

manufacturer


of the damage:


motor, parts of rotor,

overcurrent

Humming noise Lead interrupted Check lead Renew the lead

Disassembly of the

traction motor is

necessary

Check route of lead

for sharp edges and

chafing points

Rubbing noise Wrong bearing

clearance

Lift the shaft and

measure play with a

Install a bearing

with the correct

Determine causes of

change in bearing


6/9

dial gauge clearance, check

seating

clearance

Symptom Possible fault Means of checking Remedy NotesShaft bent can be determined only

after dismantling

Consult the

manufacturer

Determine the cause,

localise

consequential

damage:

Stator / rotor core

assembly, stator

winding, shaft

attachments

(e.g. transmitter

wheel for speed

controller)

Knocking noise Current flow at

bearing

Visible only after

dismantling the bearing

Consult the

manufacturer

Determine the cause

of current flow and

take suitable

measures

Bearing damage Remove the bearingcover

Consult themanufacturer

Determineconsequential

damage:

fragments in motor,

rotor core assembly

touches the stator

core assembly

Transmitter wheel

for pulse generator

loose

Remove the covers and

check seating, check

glands

Secure the pulse

generator

Motor suspension

fractured

Check the suspension Consult the

manufacturer

Localise

consequential

damage:

Shaft bearing

assembly, gearing

interface to motor

Motor suspension

loose

Check screwed joint,

check bearing

assembly, check

damping elements

Tighten the screws

at the specified

tightening torque,

renew the damping

elements

Motor coupling loose

or ruptured


make visual check of

critical locations for

cracks

Tighten the screws

at the specified

tightening torque,

renew fractured

screws

Check seal for

damage and renew,

where necessary;

with fractured screws

consult themanufacturer,

installation of screws

of a different

strength class may be

necessary

Howling noise Wrong bearing

clearance

Lift the shaft and

measure play with a

dial gauge

Install a bearing

with the correct

clearance, check

seating

Determine causes of

change in bearing

clearance


7/9

Symptom Possible fault Means of checking Remedy NotesBearing damage Remove the bearing

cover

Consult the

manufacturer

Determine

consequential

damage:

fragments in motor,

rotor core assembly

touches the stator

core assembly

Radial vibrations Excessive bearing

clearance

Lift the shaft and

measure play with a

dial gauge

Install a bearing

with the correct

clearance, check

seating

Determine the cause

Bearing damage Remove the bearing

cover

Consult the

manufacturer

Determine

consequential

damage:

fragments in motor,

rotor core assemblytouches the stator

core assembly

Balancing weights

loose or lost

Consult the

manufacturer

Determine

consequential

damage:

Small parts (screws,

weights, etc.) in

motor

Transmitter wheel

for pulse generator

loose

Check seating, check

screwed joint

Secure the

transmitter wheel

for the pulse

generator

Transmitter wheel

defines the radial

position of the

motor!

Motor suspensionfractured

Check the suspension Consult themanufacturer

Localiseconsequential

damage:

Shaft bearing

assembly, gearing

interface of

motorbox

Motor suspension

loose


check bearing

assembly, check

damping elements

Tighten the screws

at the specified

tightening torque,

renew the damping

elements

Rotor unbalance Visual inspection,

balance

Clean the rotor,

refer to Section5.5.1,

Re-balance the

rotor, refer to

Section 5.6.1

For self-ventilated motors only

Fan is loose Check seat through the

exhaust opening

Secure the fan Determine

consequential


8/9

damage (e.g. stator

winding damaged)

Symptom Possible fault Means of checking Remedy NotesAxial vibrations Wrong bearing

clearance

Lift the shaft and

measure play with a

dial gauge

Install a bearing

with the correct

clearance, check

seating

Determine causes of

change in bearing

clearance

Bearing damage Remove the bearing

cover

Consult the

manufacturer

Determine

consequential

damage:

fragments in motor,

rotor core assembly

touches the stator

core assembly

Motor suspension

fractured

Check the suspension Consult the

manufacturer

Localise

consequential

damage

Motor suspension

loose


check bearingassembly, check

damping elements

Tighten the screws

at the specifiedtightening torque,

renew the damping

elements

Loss of torque of a

machine

Lead interrupted Check lead Renew the lead Check route of lead

for sharp edges and

chafing points

Varying speed

signals

Lead to pulse

generator interrupted

Check the lead, check

the plug connections

Renew the lead,

repair the plug

connection

Tachometer loose Check fastening Secure the pulse

generator

Check seals

Pulse generator

defective

Renew the pulse

generatorTransmitter wheel

for pulse generator

loose

Remove the covers and

check seating, check

glands

Secure the pulse

generator

Oil / grease leakage N-end bearing

overgreased

Remove the bearing

cover

Remove the excess

grease

Life-cycle

lubrication

Motor coupling loose

or ruptured


make visual check of

critical locations for

cracks

Tighten the screws

at the specified

tightening torque,

renew fractured

screws

Check seal for

damage and renew,

where necessary;

with fractured screws

consult the

manufacturer,

installation of screws

of a differentstrength class may be

necessary

Polluted or

prematurely aged

grease

Current flow at

bearing

Visible only after

dismantling the bearing

Consult the

manufacturer

Determine the cause

of current flow and

take suitable

measures

Impacts or vibration Determine the cause

of impacts and


9/9

vibration

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