Ship Emergency Generator Load Testing Methods

Ship emergency generator

Ship emergency generator load Testing is important to make sure that the equipment is ready at all times.

Since the emergency generator play’s an important role onboard the ship, it’s recommended to know proper ways to operate it and make use of it as required.

Therefore, on this article, we will guide you on 2 methods to try out the emergency generator engine manually without load and with load, also testing it automatically.

Why is ship emergency generator routine testing required onboard?

Emergency generator on ship provides power in case the ship main generators lost power and creates a what we called blackout” or ” dead ship”.

As per shipbuilding requirements, the emergency generator need to have at least two modes of starting emergency generator engine . The two modes should include battery starting and hydraulic.

In some cases, some shipbuilding industry depending on the classification society may install pneumatic and battery starting or only battery starting ( but most provide back up battery in such case, if one battery fails to start, then you can use the second half).

Having said that, note, the Port state control (PSC) inspector might like to check these two modes of testing the emergency generator while onboard. Therefore, it’s important to know better about what modes of starting the emergency generator engine are equipped to your ship.

If your vessel is equipped with only battery starting, then you need to make sure that both batteries are fully charged and can start the engine at least 3-5 times or more. As per pneumatic starter, the emergency air bottle most be full at all time and can start the engine if battery fails.

How often should we carry out testing of Emergency Generator?

Manual testing of ship emergency generator

Generally, manual testing of ship’s emergency generator is carried out weekly by running it without load to check if it starts on battery mode. Likewise,the hydraulic starting modes can also be done weekly to be on a safe side or every month to ensure that it is working as required.

Manual Battery and hydraulic starting procedure for ship emergency generator

All ships are provided with instructions on how to carry out testing of ship emergency generator. They are also recommended to be posted in the emergency generator room for quick access.

However, the procedures are mostly alike;

  • Proceed to emergency generator room and locate the panel for emergency generator.
  • Put the switch on the test or manual mode from automatic mode.
  • Check the sump lube oil and cooling water level, inspect the fuel tank level, etc.
  • Hit The botton “start”on the generator local panel, then the generator will start by battery, but if engine fails to start, you can use the hydraulic starting by pressurising the hydraulic starter then activate it. Note; if successful, engine will start but will not come on load.
  • Check voltage and frequency in the meter.
  • Keep the generator running for about 10 minutes and check the exhaust temp and other parameters.
  • In other to stop the generator, hit the stop botton and wait until the engine stops or the frequency comes to zero.
  • Return the switch from manual mode to automatic.

Automatic starting of ship emergency generator

At the other hands, some company might decide the automatic start of emergency generator to be every month, while others 3 months period.

Learn more about; how to prepare marine diesel engine for start

The automatic check is done to know its automatic operation and to see whether it comes on load automatically. In such case manual blackout can be activated or stimulated.

Automatic starting procedure for ship emergency generator

Automatic starting can be activated in two ways, by stimulating or real black out.

For stimulating, electrically there is a breaker which connects Emergency Switch Board (ESB) and Main Switch Board (MSB); and there is also an interlock provided which controls the emergency generator and Main generators power output not to supply at the same time.

Therefore, to simulate blackout just open the breaker from the tie line (the location will be on the instruction posted in emergency generator room of your ship) , which can be done from the MSB or the ESB panel.

After opening the breaker, the emergency generator starts automatically with the help of batteries and will supply essential power to machinery and pumps connected to ESB.

For stopping the generator, the breaker is closed again and due to the interlock the generator becomes off load.
Now again put the switch to manual mode to stop the generator.
hit botton and the generator will stop.

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If by blackout, just open the MSB breaker from the engine control room (ECR) and the ship will went out of power, within 5-10 seconds or depending on the set point, the emergency generator will automatically start and come on load, to power the ship emergency equipments and lights.


While onboard the ship, try to get familiar with your ships emergency generator instruction Manuel and procedures provided to it.

Ask those who were onboard to inform you or check the emergency generator engine together with you, to avoid mistakes.

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