After a period of use, a
diesel generator set may develop various faults or risks of failure, necessitating appropriate maintenance. Maintenance can be categorized as minor, medium, or major, depending on the unit's cumulative operating time or the extent of damage. Generally, a diesel generator set is ready for a major overhaul after 9,000 to 15,000 hours of operation.Why is this? To understand this, users first need to understand what an overhaul entails.
A diesel generator set overhaul includes not only minor and medium repairs, but also the following:
1. Complete disassembly of the diesel generator engine;
2. Replacement of the cylinder block, pistons and piston rings, large and small bearings, crankshaft thrust washers, intake and exhaust valves, and the entire engine overhaul kit.
3. Adjustment of the oil pump and injectors, and replacement of the pump element and injector nozzle.
4. Replace the diesel generator supercharger overhaul kit and water pump repair kit.
5. Repair or replace the connecting rod, crankshaft, and engine body, if necessary.
6. Clean the motor stator and rotor.
7. Inspect the insulation properties of the stator and rotor coils.
8. Inspect and repair the diesel generator's engine control circuitry.
9. Check the diesel generator's engine's high-temperature and low-oil-pressure protection functions and replace any damaged components.
10. Check the various instruments on the control panel and activate the switch.
As can be seen from the above, a diesel generator overhaul often involves the replacement of many new parts. These newly assembled parts often have relatively rough surfaces, which often prevents them from initially forming the proper clearances with other parts. Normal operation requires a period of run-in. Diesel generator set run-in is generally divided into two types: cold run-in and hot run-in.
Cold run-in: The diesel generator will not start and instead operates using a battery or manually prying the flywheel. After the cold run-in is complete, the diesel generator oil pan should be cleaned of all lubricating oil and flushed with cleaning oil.
Hot run-in: No-load run-in should be performed first. During this run-in, the diesel generator's speed should be kept below 1300 rpm. Once all technical indicators meet the no-load run-in requirements, hot run-in with load can be performed. This period is generally around 60 hours, but the diesel generator operator can adjust it based on specific circumstances. During the load-bearing process, the load should be gradually increased from low to high until the diesel generator meets the normal hot run-in standard. Temperature control: During the hot run-in of the diesel generator, the lubricating oil temperature should be controlled within the range of 651°C-75°C, and the cooling water temperature should be controlled within the range of 70°C-80°C.
It is important to emphasize that not only does a run-in period require for overhauled diesel generator sets, but newly purchased diesel generator sets also require a period of run-in before they can operate normally under full load.
