Why Diesel Generator Overspeed and How to Prevent Overspeed

The diesel generator set generally has a specified speed range. In order to maintain the stable speed of the genset, the diesel generator set is generally equipped with a governor, which can quickly and automatically adjust the oil supply according to the load change, so as to keep the output power of the diesel generator set balanced with the load, thus ensuring the stable operation of the diesel generator set. However, for some reason, the diesel generator set may sometimes have overspeed faults, Next, Dingbo Power, a professional manufacturer of diesel generator sets, will introduce the causes of overspeed of diesel generator sets and how to prevent overspeed of diesel generator.

What is overspeed of diesel generator?

The simplest explanation for overspeed is when the generator is allowed or forced to operate beyond its design limits. Depending on the capacity of the generator, this could lead to catastrophic failure and a reduction in the life of power in the future.

What is the main reason for overspeed of diesel generator?

Missing or changing its speed regulations

Most diesel generator are designed with proper speed regulation in the system, but this does not mean that they operate normally. If the regulator malfunctions due to losing or changing its speed regulation, it may result in significant losses.

Additional fuel enters the combustion chamber

Of course, you hope the diesel generator to be filled with diesel to ensure stable power supply, but too high engine oil level will also increase the chance of generator overspeed. This is because excess oil will enter the combustion chamber and burn, causing the piston to run faster than usual, which may lead to overspeed.

Damage to other components

Like any machinery, almost all internal components are designed to work together. This is why any potential failure of any component can affect whether overspeed occurs and the degree of danger of overspeed. Some of the most noteworthy issues include the speed rules mentioned above, fuel injection pump, accelerator lever, and gear lever adjustment arm.

How to prevent overspeed?

Mechanical overspeed trip

There are two main methods that can be implemented to help prevent overspeed, with the most prominent name being "mechanical circuit breaker". Mechanical tripping typically operates, such as a braking system, where a series of components work together to slow down and stop the function of the generator's piston or turbine.

Electronic overspeed trip

For most modern diesel generator, electrical circuit breakers are probably the most commonly used circuit breakers because they can work automatically without manual interaction. This is achieved by using a large number of detectors and signals, which compare the set value (usually exceeding 10% of the rated speed) with the detected value. At this point, if an overspeed occurs, it will record it. At this stage, the generating set will automatically stop running and start decelerating according to regulations.

We hope that the above content will be helpful to users. If you are interested in diesel generator sets or have any questions, please contact us by email dingbo@dieselgeneratortech.com.