Causes and Solutions of High Voltage of Diesel Generator

In people's daily life and work, electricity is now an indispensable energy in many industries. However, in the face of power failure caused by sudden failure, many enterprises and companies have diesel generator in case of emergency. The safe use of diesel generator is crucial. If the voltage of diesel generator is too high or too low, it will affect the use of diesel generator and shorten the service life of diesel generator.

So, what causes the high voltage of diesel generator?

1. Unstable diesel engine speed.

The speed of a diesel engine can affect the voltage. If the RPM is unstable, it will result in an equally unstable voltage output.

The noise of diesel generator with unstable speed will fluctuate. This is because the engine speed fluctuates due to dirty or blocked fuel, dirty fuel filter and insufficient fuel. Just a few examples. High RPM can lead to high generator voltage, possibly due to inaccurate frequency setting (Hz) of the generator, resulting in high generator voltage.

2. Voltage regulator malfunction.

This should be the primary consideration, as a faulty voltage regulator may cause overvoltage or undervoltage.

3. Cable fault

Worn faulty output cables, damaged sheaths, and peeling insulation layers can increase resistance, leading to short circuits and voltage output spikes. If the cable looks good, please ensure that the connections and terminals are not loose or damaged. Otherwise, they will also affect the voltage output.

4. Measure the voltage before connecting the load.

Some people believe that the diesel generator has an overvoltage problem because the voltage was measured before the load was connected.

However, the output voltage of diesel generator set without load is usually higher than that of diesel generator with load.

You may also notice overvoltage during load suppression. This is because the development has led to an increase in the speed of the diesel generator, which in turn has raised the voltage to a higher level than expected.

To determine whether the voltage is too high, it is necessary to check the design threshold of the generator. If the measured output voltage does not exceed the design threshold of the generator, there is no need to worry. The voltage of diesel generator may reach the peak due to its load, but then unload the load.

So, how to control the high voltage of diesel generator?

1. Replace the damaged voltage regulator.

If the voltage regulator is faulty, it must be replaced. The faulty regulator may cause serious damage to the function of the diesel generator.

2. Clean the fuel filter.

If there is a problem with the RPM, clean the fuel filter and increase the amount of fuel. Keep the fuel lines unobstructed. In many cases, the RPM of diesel generator is too high only because the diesel generator is not configured correctly.

In addition, the throttle can be used to increase or decrease the RPM, which will lower the voltage. Use a voltmeter to measure the voltage output when adjusting the throttle. This will allow the RPM to be maintained within the required range, where the engine speed affects the governor, which affects the amount of fuel entering.

A damaged governor can cause the same RPM instability, thereby increasing the output voltage. Therefore, appropriate maintenance must be carried out to prevent the deterioration of the functions of the governor and actuator valves.

3. Replace worn cables

Replace damaged or worn cables. Each connection should be checked to ensure that it is secure and secure, and the damaged connections and terminals in the diesel generator should be checked.

The above is the reason and solution for the high voltage of diesel generator introduced by Dingbo Power. We hope it will be helpful to you. In addition, if you know more about the diesel genset, please contact us via email: dingbo@dieselgeneratortech.com.