The first part: 9 Reasons and Solutions of Starting Faults in Diesel Generators

Jul. 30, 2021

Diesel generators cannot be started or are difficult to start. There are many reasons for this failure. Combining with the analysis of the malfunctions of diesel generators, Dingbo Power will give you a detailed introduction to the reasons why diesel generators cannot start and how to solve them.

The starting failure of diesel generators is generally caused by the following 9 reasons:

1. Battery undervoltage.

2. The battery cable is loose and the contact is not good.

3.The battery head is corroded.

4.The module protection is not activated due to the failure of the oil pressure switch.

5. The control module is damaged.

6.ESC failure.

7.Fuel oil circuit failure.

8.Starting motor failure.

9.Not replace lubricating oil and fuel oil on schedule.


Next, let's take a look at the failure mode of each reason in detail and solutions.

1.Battery undervoltage.

Check whether the battery voltage reaches the rated voltage of DC24V or 48V (depending on different voltages, etc.).

Because the generator is usually in the automatic state, the electronic control module ECM monitors the status of the entire unit and the communication between the EMCP control panel is maintained by the battery. When the external battery charger fails, the battery power cannot be replenished and the voltage drops. The battery must be charged at this time. The charging time depends on the discharge of the battery and the rated current of the charger. In case of emergency, it is generally recommended to replace the battery. After the battery has been used for a long time, when the battery capacity drops severely, the battery cannot be started even if it reaches the rated voltage. The battery must be replaced at this time.

Generating set

2. The battery cable is loose and the contact is not good.

Check whether the genset battery terminal and the connecting cable are in poor contact.

If the battery electrolyte is replenished too much during normal maintenance, it is easy to overflow the battery and cause surface corrosion. The terminals increase the contact resistance and make the cable connection poor. In this case, sandpaper can be used to polish the corroded layer of the terminal and the cable connector, and then re-tighten the screw to fully contact it.

3.The battery head is corroded.

Check whether the positive and negative cables of the starter motor are not firmly connected, and vibration occurs when the generator is running, which will loosen the wiring and cause poor contact. The chance of starting motor failure is relatively small, but it cannot be ruled out. To judge the operation of the starting motor, you can touch the casing of the starting motor at the moment of starting the engine. If there is no movement of the starting motor and the casing is cold, it means that the motor is not moving. Or the starter motor is severely hot and has an irritating burnt smell, and the motor coil has been burned. It takes a long time to repair the motor and it is recommended to replace it directly.

4.The module protection is not activated due to the failure of the oil pressure switch.

If the amount of oil is insufficient, the amount of oil pumped by the oil pump will be reduced or the pump will not be oiled due to the air entering, which will cause the oil pressure to drop, and the crankshaft and bearings, cylinder liners and pistons will be intensified due to poor lubrication. Therefore, check the oil level in the oil pan before working every day to ensure that the oil level is normal. If it is insufficient, add the same type of engine oil produced by the same manufacturer. If the oil pressure switch is damaged, replace the pressure switch.

5.The control module is damaged.

Confirm that the control module is damaged, just replace the control module.

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