The suddenly stalled of the diesel generator set during operation will greatly and seriously affect the output efficiency of the unit and will transcend in the delaying the process of production and will bring huge economic losses. So what exactly is the cause of diesel generator sets suddenly stalled?

1.When the automatic shut down occurs the running speed will gradually reduce the sound of diesel generator operation and the exhaust smoke color is not abnormal.

The main reason of the shut down can be contributed by the diesel fuel inside the tank is being used up or the fuel tank switch is open or due to the blockage of fuel tank vent, fuel filter and pump or even the air has entered into the the oil circuit due to incomplete sealing resulting in "gas resistance" (with unstable speed phenomenon before the shut down).

This is the time that we should check the low-pressure fuel line with initial check of the fuel tank, filter, tank switch, fuel pump to see whether there is any blockage. Then inspect the storage of the fuel tank and see if the switch is open. Afterwards we should also inspect the tightness of the air screw on the injection pump then press the fuel pump button to see if there is any leakage of oil at the screw. If there is no out flow of oil it will mean the oil line is blocked. If there are bubbles inside the out flow of oil it will indicate that there is air in the oil and that the inspection should be carried out by sections..

2.When the automatic shut down occurs, the operation is continuously unstable and there will be an abnormal knocking sound.

Another main reason is the broken of the piston pin and the crankshaft in addition to either the broken or loosening of the connecting rod bolt, the valve spring and the falling off of the valve locking and rod valve or the valve spring is broken.  Once the diesel generator is found to be in this condition, it should be stopped immediately for inspection to avoid major mechanical accidents and should be sent to professional maintenance servicing for a comprehensive inspection.

3.When the diesel generator is automatically shut down the speed will slowly decrease with unstable operation together with white smoke from the exhaust pipe.

Another main reason is that there is water in the diesel, the cylinder gasket or the automatic decompression is damaged.  Need to replace the cylinder gasket and adjust the decompression assembly.

4.There was no abnormality before the automatic shut down

The main reason is the plunger or injector needle valve is stuck or the plunger spring or pressure spring is broken, or the connected pine fall off of the injection pump and the manipulation tie rod. When the injection pump drive shaft and the active disk fixing bolt is loosened causing the key on the shaft is sheared which will result in the sliding of the drive shaft or active disk and that the drive shaft cannot drive the working of the injection pump.

The above four points are a few common reasons for diesel generator set shutting off. The user needs to be in accordance with different situations and the corresponding reasons in carry out the investigation as soon as possible to eliminate the reason of the failure in order to resume the normal work of the unit.

KeyWords：diesel generator 、stall、running speed 、gas resistance、fuel tank、piston pin