What maintenance you will carry out on an alternator to keep in good working conditions
Generator maintenance carry out to keep in good working conditions are :-
Regular Inspection and the correct maintenance of generator and their associated gear is essential to prevent failure and inefficient operation
Before doing any maintenance work on generator
Always ensure that the generator prime mover is shut down and locked off.
Also see, circuit breaker is kicked off,auto start circuits are disabled and electric heaters are switched off and isolated.
Check for any faults
All wiring to the generator should be checked for damage or frayed insulation and tightness of terminal connections.
Check fir signs of oil and water contamination of cable insulation within terminal boxes.
Check that the cooling air Intake and exhaust openings are not blocked and are free of dirt and dust.
Inspect and clean the generator rotor and stator windings by removing dust with a dry -lint-free cloth. To remove heavy ,dry compressed air compressed air can be used ke we can be used or we can use vacuum cleaner ( It can give abrasion effect so rubber or plastic coated nozzle is used. )
Oil on windings will also reduce insulation resistance and shorten it’s life,so, to remove it we wash the windings with special depressant liquids.
Rotor slip rings must be checked for uniform (even) wear and the carbon brushes have free movement in their boxes.
Correct brush pressure can also be checked using pull type spring balance or compared with manufacturer’s instructions .
Generator excitation transformers,AVR components and rotating diodes must be kept free of dirt,oil and dampness.
for this special contact grease is used between the diode connections to prevent electrolytic action between dissimilar metals.
Measure the insulation of stator and rotor windings to earth and between stator phases.
A ducting with micron filter is going directly to the alternator casing to the stator windings for maintaining the temperature (in case of load sharing,check the temperature increase or decrease regularly.
Air gao between rotor and stator checked by filler gauge.
Clean the surface and polish it to avoid accumulation of Dust.
Soot :- Reason for deterioration of Insulation.
Moisture :- Soots and dust must not be removed by pressurized air because the small particles can get between the windings wires and hence damage the Insulation,so vaccum cleaner is used to remove these.