Common reasons and solutions for generator failure to produce electricity:
1. Cause: Bad wiring.
Treatment: Check and correct according to the wiring diagram.
2. Reason: The speed is too low.
Processing: Measure the rotation speed and keep it at the nominal value.
3. Cause: There is mud or oxide on the wiring joint between the stator winding and the generator power distribution equipment, the wiring screws are loose, the connection wire is broken and the stator winding is broken.
Treatment: Use a multimeter or light test method to find out where the disconnection is. Check the connection and contact of each wiring screw.
4. Cause: The field circuit is disconnected or has poor contact.
Processing: Use a multimeter to find out where the broken wire is, resolder the broken wire firmly and wrap it for ISOler.
Detailed information1: Under normal circumstances, due to the influence of high-order harmonics or manufacturing processes, the air gap under each magnetic pole is uneven and the magnetic potential is uneven , which results in very low voltage. If the voltage is between one and several volts, it is not dangerous and there is no need to handle it.
2: There is a short circuit in the generator winding or poor insulation from the ground, which causes the performance of the electrical equipment and the generator to deteriorate and easily generate electricity. heat. It must be repaired in time to avoid. the extent of the accident.
3: There is no voltage between the neutral line and ground when there is no load, but voltage appears when there is a load. This is due to the imbalance of the three phases. the load must be adjusted to make it fundamentally balanced.
The rannt of the generator is too large
1: The load is too large and the load must be reduced.
2: If a phase short circuit or ground fault occurs in the transmission line, the line should be inspected and restored to normal after the fault is cleared.
What are the common faults and solutions of diesel generator sets?
Diesel generators (
) are prone to breakdowns. Temperature is the most likely cause of machine breakdown in our lives. The ambient temperature is too low. When the temperature is low, the diesel engine must be preheated, otherwise it will be difficult to start. Generally speaking, the prerequisite for the normal operation of a Cummins diesel generator set is that well-atomized diesel can be accurately and timely injected into the combustion chamber, and the compressed air in the combustion chamber combustion must reach a temperaturesufficient to ignite and explode. To meet these two conditions, the diesel engine must have a sufficiently high speed and a certain temperature in the cylinder at start-up. When the Cummins diesel generator set cannot start, the reasons should be investigated from the perspective of starting, diesel engine fuel supply system and compression. Carefully examine the problem from the following two aspects to solve the essence of the problem. Additionally, the startup speed of a machine will also cause the whole problem. Startup speed is low. For manually started diesel engines, the speed should be increased gradually and then the decompression handle should be moved to the non-decompression position to allow normal compression in the cylinder. If the pressure relief mechanism is incorrectly adjusted or the valve resists the piston, you will often feel thatIt is very laborious to launch the car. Its characteristic is that the crankshaft cannot rotate when rotating in a certain position, but it can turn back. At this time, in addition to checking the decompression mechanism, you also need to check whether the meshing relationship of the timing gear is wrong. andFor diesel engines using electric starters, if the starting speed is extremely slow, it is mainly because the starter is weak, which does not mean that the diesel engine itself is defective. A detailed inspection of the electrical wiring should be performed to determine if the battery is fully charged, the wire connections are tight, and the starter is operating properly. When the starting system circuit passes the test and proves that there is indeed no fault, you should focus on why the Cummins diesel generator enginecannot work. Generally speaking, the first thing to test is the engine's ignition system, which is also the simplest test. In early ignition systems, you can easily remove the ignition coil and use a spark detector to check if the spark is normal. When choosing a spark detector, an adjustable detector is preferable to a fixed design because it allows you to adjust the detector to a smaller space so you know no sparks are occurring. Well, there's still an electric spark, but it's very strong. weak. For problems like Cummins diesel generator engine failure to start, the first step is to detect the circuit in the engine starting system. In the most basic form of composition, the starting system circuit generally consists of the following most basic elements, namely the battery, the starter motor and thecables connecting these components. Of course, the vehicle's ignition switch, starter relay or electromagnetic coil, and anti-theft system are also important components of the starting system. For Cummins diesel generator engine start failure diagnosis, the battery should be tested first. It is necessary to know if the engine cannot start due to insufficient battery power.
I hope this can be useful to you.
1. Diesel engine cannot start
Successful starting of the diesel engine must ensure sufficiently high rpm, good cylinder compression and rapid injection of well-atomized fuel. In addition, there must be a certain temperature to allow the atomized fuel to reach an ignition state.
When it cannot start, check the circuit first. If the starter does not move when you press the start button, the circooked is open or the contact is poor. If there is only an impact sound between the starter gear and the flywheel ring gear, it means that the large and small gears are not meshing. At this point, simply move the flywheel one to a few teeth. If the starter motor weakens and the speed is low, the battery power is insufficient.
If the starter motor works strongly, turns normally but does not ignite, the oil jet does not scream and the exhaust pipe does not produce smoke, it is a problem. fuel system failure. Or, although it can start, it goes out after a few revolutions, then there is air or moisture in the fuel.
When the starter reaches the starting speed, although there is fuel injection sound from the fuel injector, it is not easy to start and there is a air leak noise. After stopping the machine, use a tscrewdriver to turn the flywheel. If it is easy and weak, or the resistance is very small and the flywheel has no rebound, it means that the compression force is insufficient.
If the ambient temperature is too low or if the machine has been stopped for too long, the engine oil is too thick, the resistance of the moving parts is high, the gap between the piston and the cylinder is too large, the compression force is insufficient, etc., it will be difficult to start. At this point, use hot water or steam to preheat the machine before starting it.
2. Insufficient diesel engine power
>The main characteristics are unstable operation at low speed, black smoke coming from the exhaust at high speed, and abnormal noise. When the diesel engine has not reached the overhaul period, the lack of power is mainly due to system failure.th fuel supply and insufficient cylinder compression.
Check first when the engine is empty. If the engine can reach maximum speed when the engine is empty by increasing the throttle, the fault lies with the operating machine. If the idle speed cannot increase, the fault lies with the diesel engine.
Check the temperature at the root of the exhaust manifold. If the temperature of a certain cylinder is low, the cylinder does not work or malfunctions. You can use your fingers for touch inspection at low speed, but not at high speed to avoid burning your fingers. At this time, you may spit saliva at the root of the exhaust manifold. If the saliva does not make a “squeaking” sound, the cylinder is defective.
Pinch the high pressure oil pipe with your fingers. If the pulsation is strong and the temperature is higher than that of the other cylinderses, it means the oil pump is in good condition and the fuel injector may be stuck in the fully closed position or the pressure of the fuel injector pressure regulating spring is too high; if the high pressure oil pipe has low pulsation and the temperature is consistent with that of the other cylinders, which means the fuel injector is stuck in the fully open position. position where the pressure regulating spring is broken. If there is no pulsation in the high-speed high-pressure oil pipe and the temperature is higher than that of other cylinders, it means that the high-pressure oil pump is defective. If the exhaust pipe is spewing smoke rings at low speed, it means that the high pressure oil pump discharge valve spring is broken or the seal is failing. If there are no abnormal symptoms in the fuel system, the problem is poor cylinder compression.
During operation, if the air blown under the oil filling port increases and the ambient oil smell is strong, the gap between the piston and the cylinder is too large and the sealing is poor. If you use a screwdriver to turn the steering wheel for two weeks when parking, and the number of increases in hand resistance varies depending on the number of cylinders, you can judge that a certain cylinder has poor compression in depending on hand feeling. If there is a sound of air leaking from the gasket between the cylinder head and the cylinder block and the environment is rich in smoke and smoke odors, it means that the cylinder gasket is leaking. If there is a metallic knocking noise at the cylinder cover, related to the rotation speed and regular, this means that the gap between the rocker arm and the valve is too large. If there isn air leak noise at the cylinder head, the temperature at the root of the intake manifold is high at low speed and there is an air leak noise at the intake pipe when parking, it means the intake valve is leaking if; black smoke is emitted from the exhaust pipe at high speed, it means the engine is leaking at night. If the exhaust pipe is spewing flames, it means the exhaust valve is leaking.
3. Automatic flameout
There are many reasons for automatic flameout, but there are mainly two aspects: the fuel supply is interrupted; the other is that the moving parts are interrupted. blocked.
During normal operation, if the speed gradually slows down, the explosion sound gradually weakens, the water temperature, oil temperature and pressure are all normal, and pressing the accelerator has no effect andthe engine turns gradually. turns off after a while, use a screwdriver after parking the car. If the steering wheel turns, this indicates poor or interrupted fuel supply.
During operation, the oil pressure is normal, but the oil temperature is high, the water temperature is increased, and there is a paint smell. There is little or no water coming out of the cooling water outlet. , steam comes out, the machine runs hard and the noise is rough, when approaching the stop, there is a cylinder pulling sound and the speed gradually decreases when the car finally stops, it is difficult for the flywheel to turn. forward and backward, and the disc does not move the steering wheel after stopping. Once the machine temperature has dropped, the steering wheel can turn again. On this basis, it can be judged that the piston is seized.
During operation, the water temperature ist normal, the oil pressure drops, the oil temperature rises, there are metal shavings in the oil, the smell of burning oil, the machine vibration increases, the sound is abnormal , the speed gradually decreases and the machine stops. The inertial rotation time is short when the vehicle is running, and the steering wheel does not move after parking. The steering wheel still does not move after the machine has cooled down. It can be determined that the spindle is burning, also called axle holding.
4. The oil level in the oil pan rises.
The oil level rises, indicating that cooling water has seeped into the oil. This is mainly due to cracks in the cylinder head, cylinder liner, cylinder block and failure of the cylinder liner seal ring and oil cooler seal ring.
During verification, you can point yourre hand towards the hot air coming out of the oil filler port. If there is condensation on your hand, it means there is cooling water in the oil. When there is no engine oil pressure at low speeds or after stopping, this also indicates that there is cooling water in the engine oil.
If the oil level in the oil pan rises, starting is difficult, a water surface forms, and white smoke comes out of the exhaust at low revs, this indicates that the cylinder head is cracked and cooling water has entered the cylinder. If the oil level rises significantly, starts normally, and does not emit white smoke from the exhaust at low speeds, this indicates that the cylinder block has cracks or the cylinder liner rubber seal is damaged. defective and cooling water enters directly into the oil pan. .
5. Increase in consumptionoil mation
The increase in oil consumption is mainly caused by oil entering the cylinder for combustion, oil leakage at the cylinder block gasket and crankshaft oil seal failure.
When blue smoke comes from the exhaust at low speed, it means that engine oil is entering the cylinder and burning. This is mainly due to too large a gap between the piston and the cylinder. piston rings rotating in the opposite direction. If this phenomenon occurs after maintenance, it is due to the fact that the oil ring chamfer is installed backwards. If the screws in each joint are loose and the gasket is damaged, a leak will also occur.
If the rotating flywheel sprays oil droplets, it means that the main shaft oil seal is damaged.
6. Oil pressure drops or there is no pressure
Reasonss include oil pump damage, oil circuit blockage or leakage, pressure regulating spring breakage, pressure gauge failure, etc.
During operation, if the pressure gauge needle always stops at a lower pressure position and does not change position after stopping, the pressure gauge has a malfunction.
At the beginning of starting, if the needle of the oil pump pressure gauge does not move, the liquid level in the oil pan does not drop and the noise of the fine filter rotor cannot be heard. not be heard, it indicates that the oil pump is defective.
The oil line pressure is low and unstable, and the pressure gradually decreases, indicating a leak in the oil line. This is because the weak areas of the seal first have a small space under the action of the oil under pressure, then the space gradually expands, causing a short circuit and backflow of the lubricating oil.iant towards the oil pan.
During operation, use a screwdriver to adjust the oil pressure regulating screw. If the pressure does not change, the pressure regulating spring is broken and failing.
7. The fine oil filter is clogged.
The rotor of the fine oil filter rotates at high speed under the reaction of the two nozzles. It can continue to work for about 1 minute. the action of inertia after stopping. Otherwise, it means the rotor is clogged.
8. The gap between the piston pin and the connecting rod bushing is too large.
When operating at low speed, the middle and upper part of the cylinder emits a sharp knocking noise, which intensifies as the load increases. At high speeds, the sound disappears. The noise has nothing to do with engine oil pressure and the oil pressure gauge needle does not change. After parking, use a screwdriver to move one or two dflywheel in order to move the piston. If there is a feeling of impact, it indicates that the gap between the piston pin and the connecting rod bushing is too large.
9. The connecting rod bearing clearance is too large or broken.
When the load is applied at low speed, there is an impact sound in the lower part of the cylinder. The frequency of oscillation of oil pressure. the gauge pointer is consistent with the frequency of the sound, and the sound changes with the speed at the same time. The noise was louder than the bursting of a machine. After parking, use a screwdriver to move one or two teeth of the steering wheel back and forth. If there is a clear sound and a feeling of impact, it indicates that the connecting rod bearing clearance is too large or broken.
10. The crankshaft is broken
During operation, a loud cracking impact sound is suddenly heard, the oil pressure drops sharply and theengine stalls automatically. Use both hands to grip the front crankshaft pulley and push and pull it back and forth. If the crankshaft has significant axial movement and the flywheel fails to move synchronously with the crankshaft, this indicates that the crankshaft is broken.