In the process of using the generator, we will definitely encounter the situation where the generator cannot be started. So, why can't the generator be started? First, we have to consider the output power of the battery, followed by friction resistance, starting power, diesel twist and density, etc.!
1. The output power of the battery decreases
The best working temperature of the battery is in the range of 10 ° C ~ 40 ° C. Under low temperature conditions, the battery's electromotive force does not change much, that is, when the ambient temperature has a large change, the single-cell voltage of the battery does not drop much. However, as the temperature decreases, the viscosity of the electrolyte of the battery increases, the permeability to the plates decreases, and the internal resistance increases. To prevent the electrolyte from freezing, the lower the boundary temperature, the greater the electrolytic density. At the same time, when the diesel engine is started, the discharge current of the battery is very large, and the terminal voltage and capacity of the battery are significantly reduced. When the battery output capacity is -30 ° C, it is only about 34% of the rated output. When a diesel engine starts at low temperature, it needs a large starting power, but the low temperature will reduce the output power of the battery. The inability to drag the starter to drive the diesel engine to rotate or not to reach the minimum starting speed will cause the diesel engine to be difficult to catch fire.
2. Increased frictional resistance
The resistance torque and starting speed of crankshaft of diesel engine are mainly affected by the viscosity of oil under low temperature conditions. As the external temperature decreases, the viscosity of the oil increases or even condenses, the fluidity is poor, and the resistance between the friction pairs increases, which increases the rotational resistance torque of the crankshaft and reduces the starting speed of the diesel engine. At the end of compression, if the compressed air in the cylinder does not reach the pressure and temperature required for diesel combustion, it is difficult for the diesel engine to start.
3. Increased starting power
The larger the oil viscosity grade used in a diesel engine, the greater the power required to start the diesel engine. For example, at a temperature of -23.3 ° C, a diesel engine requires only 3.7KW starting power when using SAE10W oil, 7.4KW using SAE20W engine oil, and the starting power using SAE30W engine oil has increased to 11.8KW.
4. Increased viscosity and density of diesel
As the external temperature decreases, the viscosity and density of diesel oil increase, and the surface tension increases. It is determined that when the temperature drops from 40 ° C to -10 ° C, the viscosity of diesel increases by 83% and the density increases by 8%. In this way, the fluidity of the diesel is deteriorated, the atomization is poor, the ignition lag period is prolonged, and it is difficult to start the diesel engine.
1. Check whether the engine oil is sufficient. When there is not much oil in the gasoline generator, especially when it is overloaded for a long time, the engine oil warning switch will automatically ground the ignition coil to prevent it from firing normally. Gasoline should be replenished at this time.
2. Check whether the automatic voltage regulator is faulty. When the generator fails to start normally, it is the automatic voltage regulator that is more prone to failure. We have to remember to change new automatic voltage regulators often
3. When the generator that has not been used for a long time or has been purchased for too long can start normally, it is recommended that you remove the spark plug, inject a little oil into the cylinder, and rotate the engine a few turns. Clean and bake away moisture with a lighter. The precipitation of gasoline will also affect the launch, and the oil in the carburetor float chamber can be renewed.