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What Causes High Voltage In Diesel Generators? What Can We Do To Prevent Generator From Being Over Voltage?

What Causes High Voltage In Diesel Generators? What Can We Do To Prevent Generator From Being Over Voltage?

Dat: 2022-04-21 Clicks:

Today, diesel generators are a must-have backup power system for many industries, but the primal consideration is that the performance associated with the diesel generator must meet expectations. If the diesel generator voltage is too high or over-voltage is severe it may damage the electrical equipment if uncontrolled. So, what exactly is the causes for high diesel generator voltage? You can attribute the problem to one or more of the following factors.


1.Voltage regulator failure

The failure of the voltage regulator should be the primary consideration. A faulty voltage regulator may cause over voltage or under voltage.

2.Unstable diesel engine speed

The speed of a diesel engine affects the voltage. If the RPM is unstable, it will result in an equally unstable voltage output. The noise of a diesel generator with unstable RPM will fluctuate due to dirty or clogged fuel pipe, dirty fuel filters, and also  insufficient fuel, etc. High RPM will result in high generator voltage and the reason may due to the generator frequency (hertz) is not set accurately.

3.Cable Failure

Worn faulty output cables, broken sheaths and peeling of the insulation can increase electrical resistance that can cause short circuits and lead to voltage output spikes. If the cables appear to be intact, make sure that the connections and terminals are not loosen or damaged. Otherwise, they will also affect the voltage output.

4.Voltage measurement before connecting the loading

Some might think that the diesel generator has an over voltage problem is because the voltage is not measured before the load was connected. But the output voltage of a diesel generator without loading is usually higher than the output voltage of a diesel generator with loading.

To determine if the voltage is too high, you need to look at the generator's design threshold. If the measured output voltage does not exceed the generator's design threshold, there is nothing to worry about. The voltage of the diesel generator may peak when with loading, but will gradually decrease when the load is being removed.


How to control the high voltage of the diesel generator ?

1.Replace damaged voltage regulator

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

2.Clean the fuel filter

If there is a problem with RPM, clean the fuel filter and increase the fuel level. Keep fuel lines clear and unobstructed. In many cases, diesel generators run too high simply because the diesel generator settings are not properly configured.

In addition, by adjusting the throttle can raise or lower the RPM, and by lowering the RPM will at the same time lowering the voltage. Use a voltmeter to measure the voltage output when adjusting the throttle. This will allow the RPM to be maintained within the desired range. The engine RPM affects the governor, and the governor affects the volume of fuel input.

A damaged governor can cause the same speed instability and thus increase the output voltage. Therefore proper maintenance must be performed to prevent deterioration of the valve function of the governor and actuator valve.

3.Replacement of worn cables

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

What happens if the diesel generator voltage is too high?

High voltage in diesel generators can damage sensitive electronic components and equipment. The excessive heat generated by high voltage can damage circuit boards within the appliance. Over-voltage can cause immediate or long-term damage. If you would like more information about diesel generators or are ready to purchase a diesel generator, please contact Tide power as we have a wide selection of generator sets available and can meet any power needs. 

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