What is generator overspeed?
The simplest explanation for generator overspeed is that it’s when the generator has been allowed to, or has been forced to, operate beyond its designed limits. Depending on the generator’s capabilities, this will likely result in a catastrophic failure, as well as a reduced power life going forward.
What causes generator overspeeding?
Loss or changes to a generator speed regulations
Most diesel generators, if not all modern generators, are designed with appropriate speed regulations within the system. However, unfortunately, that doesn’t mean that they function properly. If the diesel regulator faults by losing or changing its speed regulations, then it can potentially result in a lot of damage.
Additional fuel entering the combustion chamber
Of course, you want your generator full of diesel oil to ensure that consistent power is available. However, having your engine oil level too high can also increase the chance of a generator overspeed. This is because the excess oil will enter the combustion chamber to burn, causing the pistons to operate quicker than usual, potentially leading to the overspeed.
Damage to other components
Like with any machinery, almost all parts of a generator are designed to work hand in hand to operate. This is why any potential failure with any parts can influence whether or not overspeed can occur, and how dangerous it can be. A few of the most notable diesel generator problems include the issues with the speed staying regular, the fuel injection pump, the accelerator pull rod problems and the gear rod adjusting arm.
How to prevent an overspeed
Mechanical overspeed trip
Fortunately, there are two primary approaches that can be implemented to help with preventing an overspeed. The most notable is using ‘trips’. Mechanical trips often work similarly to a brake system, where a series of components work together in order to slow down and stop the generator’s pistons or turbines from being able to function.
Electronic overspeed trip
Electrical trips are perhaps the most used trip for most modern diesel generators, as they work automatically without the need for manual interaction. This is possible through the use of numerous detectors and signals. Then, the electrical trip will compare the set value (often 10% over the rated speed) against the detected value, at which point it will register if an overspeed has occurred. At this stage, the generator will automatically cease operation and begin to slow down accordingly.
How to fix generator overspeeding
As discussed above, there are numerous causes that can result in your generator to overspeed, so why not try your best to prevent failure before it’s too late? The experienced team at Vital Power has the expertise to carry out generator service and maintenance services to ensure that your diesel generator is suitable for operation and won’t malfunction at any stage.
