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Installation...

  For more detail of installation, commissioning and trouble shooting, please click here..
»   SELECTION OF SITE
»   FOUNDATION DETAILS AND GUIDELINES
»   EARTHING SYSTEM
»   EXHAUST PIPING
»   FUEL PIPING
»   CABLING
»   BATTERY CHARGING PROCEDURE
»   SUMP CAPACITY (LITRES)
»   CHECK UP BEFORE STARTING THE DG SET
»   PRE-COMMISSIONING CHECK
»   ROUTINE CHECK POINTS
»   DO'S & DON'T'S
»   TROUBLE SHOOTING - ENGINE
»   TROUBLE SHOOTING CHART : ALTERNATOR
»   TROUBLE SHOOTING GUIDE FOR MANUAL PANEL
»   TROUBLE SHOOTING GUIDE FOR AMF PANEL
 
TROUBLE SHOOTING CHART : ALTERNATOR

Fault

Cause

Rectification

No voltage build - up

1) Insufficient residual voltage.
2) Improper connection
3) Low speed

4) Faulty Winding

5) Rotating rectifier failure

6) Faulty AVR

1) Excite the rotor using a battery.
2) Correct the connection
3) Reset the speed to the nominal.
4) Check the winding resistance and rewind if required.
5) Replace the rotating required.
6) Replace the AVR

Low no-load voltage

1) Low Speed

 

2) Faulty Rotating rectifier

 

3) Faulty Winding

1) Reset the speed to the nominal
2) Replace the rotating rectifier.
3) Check the winding resistance
and rewind if required.

Low voltage on load

 

1) Low speed at full load

 

2) AVR faulty
3) Faulty rotor winding

4) Over load on alternator

 

1) Set the rated speed of the prime mover.
2) Change AVR
3) Check the rotor winding resistance and if faulty, rewind it.
4) Operate on specified load.

High voltage on load

1) Capacitors on the load side
2) Faulty AVR setting or
AVR is faulty

1) Disconnect the PF
improvement capacitors
2) Correct the setting/Replace
AVR

Too high
no-load voltage

1) Excessive speed
2) Correct the setting
Replace AVR

1) Adjust the revolving speed
Correct the setting
Replace AVR

 

Fault

Cause

Rectification

Voltage oscillations

1) Incorrect AVR Setting

2) Thyristor load more that specified limits
3) Insufficient engine flywheel

1) Set the AVR stability pot

2) Reduce the Thyristor load

Unbalance Voltage

1) Unbalance load

2) Loose connections

3) Stator winding faulty

1) Correct the load

2) Tighten the loose connections
3) Check winding resistance

& rewind if required.

Generator does not share
(2 Generators in
Parallel Operation
KW load proportionately

Prime mover speed droop

Set prime mover speed properly.

Improperly set

Droop (Governor)
characteristic of engines.

Generator does not share
KVAr load proportionately

Quadrature droop

Interchange CT secondary

Incorrect

Correctly by QDC Pot in AVR.

QDC-CT polarity reversed

Interchange CT secondary

QDC-CT are not in
W-phase

Check and rectify

Excessive overheating of one or both bearings (temp. of bearings over
80ºC)(with or without noise)

1) Set misalignment
2) Bearing loose in end shield housing

1) Align the set properly
2) Replace the faulty End
Shield

 

Fault

Cause

Rectification

Excessive overheating of alternator frame

1) Air flow (inlet-outlet) partially clogged or hot air is being circulated either from alternator or prime mover
2) Alternator operating
at high Voltage at load
3) Alternator overloaded
4) Load PF less then
0.8 lag.

1) Check air inlet - outlets of the alternator

2) Set the voltage to rated value
3) Operate at specified load
4) Correct the load power factor

Excessive Vibrations

Defective mounting or play inthe coupling

Loose mounting Bolts

Replace the coupling & check the alignment Reset the speed to the nominal

Excessive vibration and humming noise coming from the alternator

1) Three phase alternator
is single phase loaded in excess of acceptable limits
2) Start up with no-load:if humming persists-faulty alternator stator
winding

1) Check and correct the load

2) Rewind stator

Smokes, spark or flames coming from the alternator

Short circuit in the external circuit (including wiring between alternator
and control board)

Object fallen into the machine short circuit or flash in the stator winding

Stop the gen-set immediately

 

Fault

Cause

Rectification

Alternator damaged by as significant impact which is followed by humming and vibration

Short circuit in external circuit faulty parallel connection (out of phase) Break or deterioration in the coupling Break or twist in shaft extension shifting or circuit of main field winding Bursting or unlocking of the fan Diode burnt, rectifier bridge damaged.

Stop the gen-set immediately

 
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Manufacturer India