Home Products News Contact Us
Home > Supports > Generator Sets > Diesel Generators Run At Low Load Or No Load Will Bring Greater Harm

Diesel Generators Run At Low Load Or No Load Will Bring Greater Harm

Sep. 05, 2023

Nowadays, more and more enterprises rely on diesel generators to provide stable power. In order to keep diesel generators running normally for a long time, in addition to keeping the engine well lubricated and maintained, the correct "load" is also very important. In fact, diesel generators are more hazardous to run at low or no load, why? Guangxi Dingbo Generator Set Manufacturing Co.,Ltd. will analyze in detail for you.


Results of low or no-load operation.

Diesel generator set capabilities and requirements vary from generator to generator, but there are some widely accepted guidelines. Most agree that generators should run at a minimum load of 30% of their maximum capacity. This is an absolute minimum and far from ideal, typically a load of 60-75% of maximum capacity is considered desirable. No-load operation should be avoided at all costs, except for short diagnostic runs (eg checking for proper idle speed). Consequences of low or no-load operation include:


1. Low cylinder pressure.

Diesel engines work by compressing hot air to extremes (much more than gasoline engines), so when fuel enters the cylinder, it ignites without a spark plug. Therefore, high cylinder pressure is an integral part of the normal operation of the engine. When the generator is running at low load, low cylinder pressure can cause poor combustion, reducing the efficiency of the engine. Poor combustion can cause circulation problems, soot and unburned fuel residue clog already poorly sealed piston rings, making the low pressure problem worse.


2. Low temperature.

At low loads, the engine cools and operates at temperatures insufficient to produce proper combustion. This also results in only partial combustion of the fuel. In addition to deposits, this results in a large amount of exhaust emissions. Exhaust gas is the white smoke that is common in poorly running diesel engines, dangerous fumes with high hydrocarbon emissions.


Cummins Power Generator Set

3. Lower oil performance, higher fuel consumption.

Low load operation can wreak havoc on an engine's oil distribution system in a number of ways. The hard carbon deposits formed due to poor combustion can cause the holes to be polished, thereby destroying the honing marks (grooves) of the oil. Oil will burn and oil consumption will increase. Unburned fuel can contaminate the lubricating oil due to poor piston ring sealing, as can condensate and residues, which can lead to damaging acid build-up.


4. Increased pollution.

White smoke due to low temperature unburned fuel has already been mentioned. However, this is not the only reason for the increase in pollution caused by low-load operation. The leaking oil enters the combustion chamber through the poorly sealed piston ring and is burned and produces obvious blue smoke, and the black smoke is the result of the damaged injector.


Low or no load operation can cause many other problems, including the specifics of each case or low or no load will determine the severity of each problem:

(1) The pressure in the crankcase increases.

(2) Excessive turbocharger wear and oil leakage (if present).

(3) Carbon deposits on many surfaces, including valves, pistons, and exhaust manifolds.

(4) Engine Exhaust Fluid: Black oily fluid leaking from the exhaust manifold.


In some cases, the diesel generator set can run under the optimal load for a short time, and no-load operation is recommended not to exceed 15 minutes. Correct operation and maintenance of the diesel generator set can ensure that the generator set can be stable for a long time.


Guangxi Dingbo Generator Set Manufacturing Co.,Ltd. is a manufacturer of professional generators, diesel generator sets, Cummins generator sets, Volvo generator sets, etc. The company has advanced testing equipment, excellent production technology, professional manufacturing technology, perfect quality management system, and Strong R&D technical strength. It can provide 15KW-2500KW various specifications of universal, automatic, four protection, automatic switching, low noise and mobile, etc., high-quality, low-energy generating sets to meet customer power needs, and can also meet users' different voltages and different frequencies, as well as the power supply system of multiple units connected in parallel, welcome customers to inquire. For more details, please contact us with sales@dieselgeneratortech.com

Contact Us
  • Add.: No. 10 Kechuang Road, High tech Zone, Nanning, Guangxi, China
  • Tel.: +86 771 5805 269
  • Fax: +86 771 5805 259
  • Cellphone: +86 134 8102 4441
                    +86 138 7819 8542
  • E-mail: sales@dieselgeneratortech.com
Follow Us

Copyright © Guangxi Dingbo Generator Set Manufacturing Co., Ltd. All Rights Reserved | Sitemap

Update cookies preferences
Contact Us