Lubricating System and Fuel System Maintenance Tips for Cummins Diesel Generatorby Generator D. Diesel Generator
Introduction of lubricating oil
The main function of lubricating oil is to reduce friction and wear by providing a long-lasting protective oil film between the moving parts of the diesel engine. It also prevents corrosion on the surface of each component. High temperature cylinders and bearings are highly dependent on the oil film. Lubricating oil also has a very important cooling effect on many components of the genset.
For diesel engine oil, please use the various types of specifications described in the table below. For details, refer to the random information of the diesel engine. (SAE is the American Society of Automotive Engineers temperature/viscosity index, such as 15W/40, etc.: API represents American Petroleum Institute lubricant quality system).
Attentions to lubricating oil
a. Do not start or operate the diesel engine when the lubricating oil filling is opened to prevent the lubricating oil from spraying out.
b. The use of lubricating oil that does not meet the above specifications will result in operational loss and poor reliability.
c. If the diesel engine uses the wrong type or quality grade lubricant, the warranty service will be invalid, should avoid different specifications, different brands of lubricating oil mixed use.
Replace lubricating oil and oil filter
I. Hot lubricating oil is easy to cause scald. Please avoid the contact between hot oil and skin. Add lubricant to ensure that the lubricating oil is between the lowest and highest oil level mark. Be sure to follow the recommended lubricant replacement period. When replacing lubricating oil, be sure to replace oil filter at the same time.
II. Replacement steps
a. Remove the bottom screw plug, drain the lubricating oil, install the bottom screw plug, and remove the filter;
b. Clean the filter mounting seat to avoid dirt entering the engine when installing new filter;
c. Stop the engine after running to the operating temperature;
d. Fill the new filter with lubricating oil, apply some oil to the gasket, and screw the filter to the engine by hand until the gasket touches the base, and then tighten it;
e. Add the lubricant to the appropriate level;
f. Start the generator set, check whether the lubricant pressure is normal, check for leakage around the filter.
The fuel system of the standard genset includes: fuel tank, fuel supply pump, fuel filter, manual oil pump, fuel injection pump, fuel injection nozzle and related oil pipeline.
Only fuels that meet the quality specified in the following standards shall be used. It must be kept clean during refueling and fuel system operation. When working on the fuel system, it must be confirmed that the engine has cooled down. The splash of fuel on hot surface or electrical components may cause a fire.
The composition of the diesel oil has a very important effect on the operation and service life and the emission components of the diesel engine. In order to obtain the specified power, fuel economy and the emission standards specified by the local environmental protection department, only clean light fuel that meets international and national standards should be used.
Light diesel oil is used for fuel in high-speed diesel engines above 1000r/min. The current standard for light diesel oil products is GB252-2000 "light diesel oil" standard. The grade of diesel oil is based on the freezing point of diesel. Customers should choose the appropriate diesel grade according to the temperature of the workplace. (See Table 5.2)
Minimum ambient temperature (°C)
Light diesel grade
Minimum ambient temperature (°C)
Light diesel grade
a. The fuel recommended in the operating manual must be used. For diesel engines, the use of low-quality fuel can cause the control rod to stick and the engine to rotate at an excessive speed, resulting in damage to the generating set or even serious personal injury. Inferior fuel will also shorten the maintenance cycle, increase maintenance costs, and reduce the normal service life of the gen set.
b. When adding fuel, there is usually a risk of fire and explosion. No smoking when refueling.
c. Do not allow the fuel oil to overflow the fuel tank. The fuel tank cover should be sealed safely.
d. Water in the fuel can cause corrosion of metal parts in the fuel system, and it can easily cause fungi and microorganisms to grow in the tank, which can block the filter. When the fuel water content is relatively large, it is recommended that the user install a oil-water separator for the genset. Make sure that the fuel entering the body is free of water or other impurities. All models of medium and high units can be equipped with oil-water separators according to the requirements of users. The oil-water separators are not part of the standard configuration when the unit leaves the factory. When users need to order, it should be separately stated.
Replace fuel filter
a. Keep it clean and do not allow any dirt to enter the fuel system.
b. In order to avoid fuel splashing on hot surface and causing fire, the fuel filter replacement must be carried out under the condition of cooling machine.
c. Remove the filter and apply a little oil to the gasket of the new filter. Screw the filter by hand to bring the gasket into contact with the seat. Then tighten again, do not screw more, and exhaust the air from the fuel system.
d. Start the unit and check for leaks.
Fuel injection pump
a. The fuel injection pump is driven by a timing gear transmission mechanism in the diesel engine. The pump setting is measured with a lift meter when the base circle of a particular crankshaft angle rises.
b. The fuel injection pumps used in medium and high diesel generator sets are superior in quality and reliable in performance, which can ensure the long-term normal use of users.
Fuel spray nozzle
a. Equal distribution of fuel oil for reliable ignition and combustion.
b. Inject fuel oil directly into the combustion chamber and provide optimal mixture of fuel oil and air. The injection pressure can be pre-adjusted by a spring.
Created on Sep 16th 2019 20:25. Viewed 494 times.