How To Synchronize Generator on Ship (Step by Step Guide)

Synchronizing a ship generator is one of the most vital things to do before propelling with another generator.

Maritime law dictates that any ship should have at least two generators. Ensure you maintain your generators at a regular interval.

Therefore, I will focus on generator synchronization when you need to use multiple generators or you need to start another one after stopping the other.

You can synchronize a ship generator with one of the two methods available:

  • Three bulb method
  • Synchro scope

Three bulb method is preferred, especially during emergencies.
It is important to keep certain parameters in check before paralleling the generators.
Some of the important things you need to keep in check include:

  • Phase
  • Load
  • Frequency
  • Voltage

Now let’s see a manual procedure to synchronize a ship generator.

What is generator synchronization?

Generator synchronization is the process of matching two generators‘ parameters like:

  • Phase angle
  • Voltage
  • Frequency
  • Waveform of the generator
  • Phase sequence
  • Other sources with running power system

A ship generator cannot supply power to the rest of the power system unless its frequency, voltage, and other parameters match that of the electric network.

Therefore, synchronization is done by controlling the speed of the generator engine and the exciter current.

The need to synchronize may arise when you want to supply sufficient power to the load by making two or more generators work together.

Electric loads in the ship are not constant hence vary from time to time depending on the available load.

Because of that, it is necessary to interconnect two or more generators to supply a larger load.

Generator synchronization before starting

  1. It is important to start by notifying the bridge soon after the synchronization decision is made.
  2. Put on line the generator to be synchronized. However, you should use the fuel from the hand pump to prime the engine. Remember to check the engine block (should be off)
  3. Turn on the generator engine after opening the air valve
  4. Once the engine is on, check for important elements like cooling water and oil pressure to ensure there are adequate. Feel the pipe to ensure the cooling water pump is working correctly.
  5. Close the air valve if everything checks to be good

I have three generators on my ship; two are for normal working conditions, while the remaining one is kept for stand-by.

Whenever I need extra power or run parallel generators, the standby generator is put in line.
Therefore, I always synchronize the generator I want to align with the other running generators.

Synchronizing procedure

Once you have started your generator engine, synchronization is carried out properly.

  1. Check if pressure gauges are good in the engine control room.
  2. Check the brightness of the ground lights and ensure they are working properly in the generator control panel.
  3. It is important to look at the open position synchronizing relay. Bring the lead or the running generator to the desired or normal optimum parameter: 60 hertz and 480 volts.
  4. Bring the on-coming generator (synchronized generator) to your desired parameter.
  5. Be keen on the needle after turning on the synchronizing relay.
  6. Initially, the needle in the synchronizing gauge will move at changing speed. Ensure the needle moves in a slow-motion in the clockwise direction by adjusting the generator speed.
  7. Press the close brake button again once you have achieved a steady speed of the needle and when the needle is ¼ of its way.
  8. Energize the breakers once the needle reaches the 11‘ o clock position.
  9. Check the synchronized generator parameters. They should match with the leading generator: 60 hertz and 480 Volts.

What to do after synchronization

You should carry out some important activities after the main synchronizing job is done.

  1. Change the off-going generator‘s governor control.
  2. Remove all the load shown in the gauges as soon as possible to avoid it acting as reverse power (load). You can achieve this by pulling the trip breaker once the generator is off-line.
  3. Use the toggle switch to stop the engine once it is off-line
  4. Ensure to turn on the engine heat blocker after the engine is off.
  5. Constantly check the control panel gauges for even distribution of load and adequate pressure.

Remember, you can evenly distribute the load by varying fuel supply.
For the current to be equally shared, you need to vary the excitation current that affects the generator‘s power factor.

How to synchronize generators on the ship

It is important and easy to synchronize generators on the ship to supply the required power to the load.

You can use two methods to synchronize ship generators:

  • Three bulb method
  • Synchro scope

The step-by-step guide for synchronizing ship generators is listed above.