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38 Common Problems of Diesel Generator Sets Part 1

Jan. 07, 2022

Let's learn about common problems about diesel generators together.


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1. The impact of different climates on the operation of diesel generating sets:



Dust and sand

Salt water and mist by the sea

The air contains corrosive gases, such as sulfur dioxide


2. Composition of diesel generator set:


Diesel engine, generator, controller. Other components: base, base fuel tank, radiator, water tank, recoil pad, anti-speaker, muffler, silent box and other components.


3. How long is the replacement time for the three filters of the diesel generator set:


Air filter: 1000 hours, can shorten the replacement cycle for different environments.

Diesel filter: the first time it works, it is replaced within 50 hours, after which it is generally replaced within 400 hours. If the quality of diesel used by the user is not good, shorten the replacement cycle.

Oil filter: Replace the oil filter within 50 hours of operation for the first time, and usually within 200 hours after that.


4. How to identify the authenticity of the engine:


Appearance: For professionals who are familiar with the engine, the authenticity of the engine can be distinguished by the appearance, color, and overall color difference of the engine.

Logo resolution: The diesel engine body has the logo label of the corresponding brand.

Nameplate resolution: The engine number is marked on the nameplate on the engine, and there are corresponding codes on the cylinder block and oil pump. Call the original factory to confirm the code, and you can know the authenticity of the power.


5. Introduction of motor protection class IP:


I represents the level of preventing solid foreign objects from entering, the highest level is 6;

P represents the level of preventing water ingress, and the highest level is 8.


For example, protection level IP56, IP55, etc. (The protection level of D.NJ Power generator is IP56)


6. Introduction of motor insulation level:


The insulation grade of the motor is divided according to the heat resistance grade of the insulating material used, and is generally divided into 5 grades:

A grade 105 degrees

Class E 120 degrees

Class B 130 degrees

Class F 155 degrees

Class H 180 degrees

The theater grade of D.N Power generator is H grade.


7. Introduction to noise level:


30-40 decibels is an ideal quiet environment. More than 50 decibels will affect sleep and rest. Above 70 decibels will interfere with the conversation and affect work efficiency. Long-term living in a noise environment above 90 decibels will seriously affect hearing and cause neurasthenia, headaches, blood pressure and other diseases. If you are suddenly exposed to a noise environment of up to 150 decibels, the auditory organs will be traumatized, causing the tympanic membrane to rupture and hemorrhage, and both ears will completely lose hearing. In order to protect hearing, the noise should not exceed 90 decibels; in order to ensure work and study, the noise should be controlled not to exceed 70 decibels. In order to ensure rest and sleep, the noise should be controlled not to exceed 50 decibels.


8. The purpose of parallel operation of diesel generator sets;


Expand power supply capacity.

Improve the reliability of power supply and realize uninterrupted power supply.


9. The role of ATS:


ATS is a switch between the mains power supply and the power generation power supply. Two sets of switch contacts, one for power generation and the other for mains. The automatic switching can be realized through the command of the controller.


10. Fuel consumption calculation:


Fuel consumption (L/h) = diesel engine rated power (kw) X fuel consumption rate (g/kwh) / 1000 / 0.84 (the density of diesel 0# is 0.84kg/L)


11. Debugging steps of diesel generator set:


Diesel engine inspection---generator inspection--no-load commissioning--on-load commissioning--filling in the commissioning report--cleaning the scene


12. Generator sets can be divided into several categories in terms of energy:


Nuclear, hydraulic, wind, and firepower. The firepower is divided into coal, diesel, gasoline, gas, and biogas. The generators we currently operate are mainly diesel generators. Diesel is divided into light diesel (0# diesel, often used in high-speed diesel engines) and heavy oil (120#, 180# diesel, often used in medium-speed diesel engines and low-speed diesel engines).


13. Main functions of the control system:


With manual, automatic, test shutdown

With various safety protection functions

To memorize various faults in operation

LED fault display alarm

Display voltage, current, frequency, etc.

It can be connected to a computer, but the controller needs to have RS232 and 485 ports


14. What happens if the diesel generator set is overloaded for a long time:


The unit usually cannot be overloaded during operation, but it can withstand short-term overload. If the unit is overloaded for too long (over the rated power), some conditions may occur.



Cooling system overheated

Generator windings are overheated

Decomposition of lubricating oil concentration causes low oil pressure

Reduced unit life


15. What happens if the load of the unit is too low?


If the unit is operated at low load for a long time, the water temperature will not rise to the normal temperature, the viscosity of the oil will increase, and the friction will increase. The heating of the oil in the cylinder that should have burned causes a paint surface on the cylinder head gasket. If the low load continues, blue smoke may appear, or the surface paint of the cylinder head gasket needs to be removed, or the cylinder head gasket needs to be replaced.


16. What should I pay attention to when installing the exhaust system?


 The generator set has its standard configuration, such as industrial muffler, flexible exhaust connection, elbow. The user can install the exhaust system with the supporting facilities provided. But you need to pay attention to the following points during installation:


(1). Make sure that the back pressure is lower than the set maximum value (usually, don’t be lower than 5Kpa)

(2). Fix the exhaust system to avoid horizontal and vertical pressure.

(3). Leave room for contraction and expansion

(4). Leave room for vibration

(5). Reduce exhaust noise


17. When the temperature of the diesel engine is too high, is it feasible to add cooling water immediately?


Absolutely not, the cooling water can only be added until the engine has cooled to room temperature. If the cooling water is suddenly added when the diesel engine is short of water and overheating, it will cause cracks in the cylinder head, cylinder liner, cylinder block, etc. due to the drastic changes in cold and heat, causing serious damage to the engine.


18. ATS self-switching operation steps:


(1). Module manual operation mode:

 After turning on the power key, press the module "manual" button to start directly. When the unit starts successfully and runs normally, at the same time, the automation module also enters the self-checking state. The display enters the automatic closing and grid connection.


(2). Fully automatic operation mode:

 Set the module to the "automatic" position, and the unit will enter the quasi-start state. In the automatic state, through the external switch signal, it can automatically detect and judge the state of the mains for a long time. Once the mains fails or loses power, it will immediately enter the automatic start state. When the utility power comes in, it will automatically switch to open and reduce speed to stop. When the mains power returns to normal, the unit will automatically trip and exit the network after 3S confirmation of the system, with a delay of 3 minutes, automatically shut down, and automatically enter the next automatic start-up state.


19. What should I do if the cylinder sealing of diesel generator sets becomes low and it is difficult to start?


When the engine is cold-started, especially in winter, because there is little oil on the piston ring and cylinder wall, the sealing effect is not good, and the phenomenon of repeated starting and failure to run on fire will occur. Diesel generator sets sometimes seriously affect the sealing performance of the cylinder due to heavy cylinder wear, making it more difficult to start. In this regard, the injector can be removed, and 30-40ml of engine oil can be added to each cylinder to enhance the sealing performance of the cylinder and increase the pressure during compression.


20. Diesel generator self-protection function.


Various sensors are installed on diesel engines and alternators, such as water temperature sensors, oil pressure sensors, etc. Through these sensors, the operating status of the diesel engine can be displayed to the operator intuitively, and with these sensors, an upper limit can be set. When the limit value is reached or exceeded, the control system will alarm in advance. At this time, if the operator does not take measures, the control system will automatically shut down the unit. The diesel generator set adopts this method to protect itself.


The sensor plays the role of receiving and feeding back various information. It is the control system of the diesel generator set that really displays these data and performs the protection function.


If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.

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