Beidou Power specializes in manufacturing various types of diesel and gasoline generator sets. The company has a professional technical team and advanced testing equipment. Now, we would like to remind customers that when purchasing generator sets, do not only focus on the price of the generator sets. What needs to be particularly noted is the method of operating the generator sets when they are purchased and put into use. Many faults of the generator sets are often caused by foolish operation methods. Some customers do not understand and shut down the diesel generator set under load, which causes a series of malfunctions. Now, Beidou Power Manufacturer will answer for you why diesel generator sets cannot be shut down under load!
The shutdown of a generator set under load has little impact on the generator. When the generator stops, the speed of the diesel engine and the power of the flywheel drop sharply, and the output voltage, frequency and power of the generator also decrease accordingly. Here, an inrush current may be generated due to the self-holding effect of the magnetic circuit of the winding. Whether it is harmful or not depends on the specific situation.
When shutting down under load, the rated diesel prime mover is affected. As is well known, diesel engines generally rely on water circulation for cooling and heat dissipation. The power for the cooling water to circulate along the pipes comes from the built-in water pump of the diesel engine. Now, the common practice is to drive the water pump through a belt from the camshaft of the diesel engine. Then, when shutting down under load, the diesel engine does not rotate, and the water pump does not work either. If the water circulation is forcibly stopped, what consequences will there be? Sometimes the consequences can be very serious. Imagine that a diesel engine with high temperature and heat suddenly cannot effectively dissipate heat, and the damage to the hardware is an inevitable consequence.
Shutdown under load, in other words, means that the load torque is greater than the flywheel torque of the prime mover. What’s going on? To put it simply, it’s a braking shutdown, which has a serious impact on the crankshaft. For most controllers nowadays, if you give them a shutdown command, they usually open the switch to remove the load before shutting down. Here, there is no such thing as braking shutdown. However, the heat dissipation issue still exists. Generally, the way to shut down is to first remove the load and then run it idle for several tens of seconds (or two or three minutes at a longer time) before shutting down. This is called the cold machine time. Additionally, Although the braking shutdown no longer exists, there is still the impact of sudden load unloading. Sudden load unloading is not a good thing in the first place. It’s fine when it’s half a load, but if it’s fully loaded, it will aggravate the short-term instability of the machine, increase the heat of the machine, and then cause an immediate shutdown. This situation not only harms the heat dissipation system of the unit, but also shortens the service life of the unit in the long run.
Here we would like to remind users that they must operate the generator set in accordance with safe and proper procedures. Do not operate it blindly or randomly. This not only increases the failure rate and cost of the generator set, but more importantly, it affects the work efficiency.
For more questions about the generator set, please call the Beidou Power team. More than ten years of professional production and sales of power generation equipment experience, more professional engineer team to serve you, choose Beidou power is to choose rest assured, welcome on-site factory inspection.
Post time: Aug-25-2025