How to Correctly Operate Yuchai Engine
We know that improper engine operation will cause serious damage to the machine. If you don't know how to correctly operate a diesel engine that used in a diesel generator, take some times to read this article. It mainly talks about Yuchai engine - China famous engine brand.
I Selection of fuel, lubricating oil and coolant
1. Fuel
The fuel should he selected according to ambient temperature. The selection should comply with Light Diesel Fuel ( GB252 choice fuel and first class fuel).
Ambient temperature
Above 4℃
Above 5℃
Above 14℃
Above 29℃
Above 44℃
Light diesel fuel #
0#
10#
20#
35#
50#
2. Oil
Lubricating oil should be selected according to the ambient conditions. The class of oil should not be lower than CD class of GB111-1997.
Ambient temperature
Summer
Above 0℃
Above 15℃
Above 30℃
Diesel fuel #
15w/40CD
15W/30CD
15W/30CD
5W/30CD
3. Coolant
The coolant should be anti - freezing, especially when the engine is used he plateau and in cold weather ( below OT ). It is good for the engine. The most used anti - freezer is glycol - water, which is a mixture of glycol and water ( soft water is best,. If well water, spring water or other a liter is used,it should be mixed with 2g tri - sodium phosphate and a liter water in order to be softened). Selection of different proportionality coolant should vary with the ambient temperature.
Glycol percentage
Density of glycol-water g/m³
Freezing point ℃
28
1.034
10
38
1.050
20
48
1.063
30
55
1.072
40
60
1.078
50
68
1.087
68
Note: When the percentage of the glycol is above 68% , its freezing point rises. So the percentage of the glycol should not be above 68% when.you make up anti - freezer. Clycol is a transparent, viscid, poisonous .liquid. Wash your skin with water immediately if it contacts your skin. Glycol is flammable. So, do not weld or light fire when there is .coolant leakage.
When there is an emerS;ency, anti - freeze can be replaced by water, such as tap water and rain water. If well water, spring water other hard water is used, add 2g tri - sodium phosphate per liter water in order to soften the liquid. If hard water is not softened before using as a coolant, there will be scale on the wall of water jackets of diesel engine and the deposit will weaken cooling effect and cause the engine to overheat.
II preparations before starting the diesel engine
To make sure that the engine would run properly, the following step should be done before starting the engine every time.
1.Check the oil level in the oil sump. The level should be within the upper and lower scale limits of the oil gauge. I~ the oil volume is not enough, add some oil as required.
2. Check the diesel fuel level in the fuel tank, add some-fuel if necessary.
3. Check the coolant level, add some coolant if necessary.
4.Check if there is air in the fuel pipe. De - aerate fuel if there is air in the fuel pipe.
5. Check if electrical system works properly.
6. Check the tension of the driving belt. The tension should he moderate as required.
7. Perform every kinds of technical maintenance as required.
III．Starting the diesel engine
The engine cannot start unless the preparations have been completed and confirmed to comply with requirements.
1, procedures of starting the diesel engine
Switch on the start switch or press the button of start. After the engine starts, switch it off.
2. Check following items after start
a. Check the oil pressure. It should not be lower than 0.1MPa
b. Check whether the water pump operates properly and whether the coolant runs into water jacket of the diesel engine.
c. Check the leakage of oil, fuel and oil. And if there is leakage, shoot the trouble.
d. Check if there are abnormal noises
Attention
1. Do not crank the engine for more than 10 seconds at a time. And if the engine fails to run after the cranking, the cranking should not be repeated within at least one minute. If the engine fails after cranking three times successively, troubleshoot and crank again.
2. Switch off start switch immediately after starting the engine. If diesel engine, through the flywheel gear, will drive the starter rotating very high speed and the starter will bum.
3. After the start, engine should not speed up abruptly.
4. When the engine must be cold - started and it has no oil and temperature stabilizers, the engine should not run at a high speed intermediately. In this case, the engine should keep idling for 5 minutes with no load.
IV．Operating the diesel engine
1. requirements of using engine
a. When the diesel engine is cold - started, it should keep idling for 5 minutes with no load. Even if it is warm - started, the engine must run after the oil pressure is established.
b. When the diesel engine is cold - started, it should not run with the throttle completely open and should not run with full load and at high speed. It should steadily speed up and run after water temperature rises above 60℃.
c. New engine or an engine after overhaul needs 50 - hour break - in. Screw off the break -in stop only after this break - in period. Afterwards engine can operate as normal.
2. Points that always need careful check when engine is running.
a. Check if the lubricating oil pressure is normal. The pressure should be lower than 0.1MPa when the engine is idling and should be within 0.25MPa and 0.6MPa when the engine is running at high speed.
b. Check if the coolant temperature is normal. The temperature should be controlled within 75℃and 90℃.
c. Always observe abnormal noises when the engine is running. If there are abnormal noises, stop the engine and troubleshoot.
d. Pay attention to the sealing of every water passage and the fuel pipe. If there is leakage, remedy it immediately.
Attention
1. Do not keep the engine idling for more than 5 minutes, not more than 10 minutes at its minimum.
2. Do not run the engine if it malfunctions.
3. The exhaust manifold temperature is very high when the diesel engine is operating. Do not touch the exhaust manifold lest skin be scalded. Do not place inflammable or explosives near the exhaust manifold in case of accident.
V．Stopping the diesel engine
1. Keeps the engine idling for 3 t0 5 minutes before stopping it, especially when the engine runs with heavy load and at high speed. Do not stop the engine sharply unless there is an emergency.
2. When the ambient temperature is below 5aC and the coolant is below 5℃ and freezing, discharge all of the coolant water after stopping the engine to avoid engine damage by frost crack.
3. Generally, discharge all of the coolant water when the engine will be parked for a long time.
4. Shoot troubles that occurred when engine was running after engine stops. Always check the engine and make sure that the engine runs in proper technical.
5. Maintenance must be available as required after diesel engine stops.
VI． Storage
1. diesel engine should be stored in warehouse, which is dry, with ventilation, and without corrosive matter.
2. If diesel engine will be stored for a long time, discharge all of the coolant. Diesel generating set must be well cleaned with necessary oil sealing in case of rusting.