Q1:
Low fuel level alarm (With alarm automatic series)
Problem description:
Low, fuel level alarming light on

• Inspect the daily fuel tank capacity, add fuel when necessary
• If there is a fuel-conveying system, check it according to regulations in 9.4.3
• Once the cause identified, press the reset button quenching alarm

Q2:
How to identify a fake domestic diesel engine?
Check whether there are factory and product certifications, which are the “identity” and must be included by authorized diesel engine manufacturers.

• The nameplate number;
• Diesel engine number (Usually on the surface of flywheel end that has had a mechanical machine, with the font in convex style);
• Pump nameplate number. These three numbers must be completely accord with the numbers on the diesel engine. If there is any doubt, you can report it to the manufacturer for verification.

• Check the active power of the diesel engine, determine the economic power and standby power. The way for checking active power: rated power of diesel engine for 12-huors operation multiply 0.9 getting a data, if the rated power of the alternator is less than or equal to the data, the rated power of the alternator will be the active power of this diesel engine, otherwise, this data will be the active power of this diesel engine.
• Check whether the diesel engine is self-protective. For example: differential protection, over-current protection, over-voltage protection, inter-turn protection etc.
• Verify whether the electrical wiring of the diesel engine is qualified, whether the protective grounding is reliable and whether the three-phase load is balanced.

• Apparent power is often used to indicate the capacity of transformers and UPS in China, the unit is KVA.
• Active power is 0.8times of apparent power, often used to express power generator and electric equipment in China, the unit is KW.
• Rated power of the diesel engine is the power under 12-hour continuous operation.
• Max power is 1.1 times of the rated power, with the max power only allowable for 1-hour operation in each 12 hours.
• Economic power is 0.75 times of the rated power, which can keep the diesel engine work for unlimited time, which producing less fuel consumption and low machine failures.

• There must be sufficient water in the water tank to keep the machine operated in allowable temperature range.
• The lubrication oil must be sufficient but not too much and keep the machine working in allowable voltage range.
• The frequency stabilizes around 50HZ and the voltage around 400V.
• The three-phase current should be within rated range.

• Oil lubricating system;
• The fuel system;
• Control and protection system;
• Cooling system;
• Exhaust system;
• The starting system

Why oil leakage of exhaust pipe appears when the alternator is in low load operation?
The engine adopts several pressure seals inside, such as cylinder-liner-piston-between the piston rings, supercharger-between the rotor shaft of the supercharger, which can only work when the engine is operated in 1/3 load, so when the engine is operated in low load, leakage may appear, and the foreign engine manufacturer have stressed this point in their products manuals.

• Poor sealing effect for the piston-cylinder liner, the engine oil flows upward to the combustion chamber, resulting in fuel combustion and exhaust of blue smoke.
• For the supercharged diesel generator, low-load, no-load and low supercharge pressure operation can easily lead to a poor sealing effect of supercharger oil seal( non-contact), with the fuel flows upward to the pumping chamber and entering into the cylinder with the inflow air.
• Part of the fuel flow upward to the cylinder is in combustion, but part of it is in incomplete combustion, which can lead to carbon deposits in the air valve, air inlet, piston top and piston ring, and some was discharged with the exhaust, which will accumulate fuel in the cylinder air vent and result in carbon deposits.
• If the diesel engine works long with low load, there will be serious consequences that may lead to overhaul in advance, which covers wear on the components and severe combustion condition for the engine.

Therefore, the foreign diesel engine manufacturers all put emphasis on reducing operation of diesel engine under low load/no-load condition, and regulate that the minimum load shall not lower than 25-30% of the rated power of the engine, no matter for the naturally aspirated engine or the supercharged engine