Marine generator servicing, includes both periodic and emergency maintenance.

Periodic maintainence is better than having to carry out emergency maintenance, after a failure.

Marine generators are all three-phase power.

Three-phase means that there are three output ‘bus bars’.

Bus Bar’ is the name for the three metal connectors, which provide the output voltage, from the generator.

Each ‘phase’ is a voltage, which is 120 degrees from the other two voltages.

To explain this, remember that there are 360 degrees in a a circle.

360 divided by 3 (the three phases) = 120 degrees.

Periodic Maintenance

Periodic checking of Marine Generators, reduces the chance of unexpected failure.

There are a number of periodic checks that can be carried out:

Mechanical Factors

Marine generators, are driven by a Prime Mover.

The Prime Mover, is normally a slow or medium speed diesel engine.

A drive shaft connects the Prime Mover, to the Generator.

The drive shaft is supported using bearings.

Check bearings for mechanical wear.

This can be done using Feeler Guages, and the results checked against manufacturers stated tolerances.

Generator bearings, that support the Stator, can also be checked.

Excitor’ bearings can also be checked.

Electrical Checks

Insulation Resistance Checks, using Insulation Resistance Meter.

Check Automatic Voltage Regulator, using voltmeter.

Excitor Diode Plate Checks, using diode tester.


Routine periodic maintenance is prefereable to emergency maintenance.

Marine generator servicing, includes both mechanical and electrical checks.

This is an introduction, to Marine Generator Servicing.

For more in depth in person or online training, contact me via Linkedin

Published by Craig Miles

Craig Miles

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