According to the requirements of the maintenance regulations, diesel generators should be 5-10 minutes of no-load test machine per month. Many people in the industry believe that the time of no-load test machine should be the lower limit specified in the maintenance rules, which is 5 minutes. Cummins and many other brands of diesel generator sets clearly state that the no-load test time can not exceed 5 minutes.
Because the diesel generator set runs for a long time with no load or idle speed, it is easy to produce carbon deposits, which will reduce the engine output power, affect the output of the entire unit, and even cause the phenomenon of normal operation. Once the load is actually loaded, the diesel generator set will not be normal. Major failure of output power.
Formation and hazards of carbon deposits: Because the temperature of the combustion chamber is too low, the fuel cannot be completely burned, which will cause carbon deposits, which will block the nozzle holes and piston rings of the fuel injectors, and there will be "black oil" overflow from the exhaust pipe. It may also cause the valve to get stuck. Some unburned diesel will flush the gas
Lubricating oil on the cylinder wall and diluting the oil in the crankcase make all running parts in the engine suffer from poor lubrication.
Regardless of the use of naturally aspirated or supercharged models, diesel engine manufacturers emphasize that the no-load operation time should be minimized, which can be 5 minutes. Excessive no-load test time can also cause oil leakage in the exhaust manifold.