Running out of diesel generator fuel
Lack of fuel can be for the following reasons:
It is a sign of fuel leakage in the diesel generator, which happens due to human error or fuel pump system error.
There is always the possibility that the fuel gauge is not working properly.
Due to the static nature of the diesel generator, there is a possibility of fuel thickening, so it is better to check the fuel of the diesel generator routinely.
Failure of the heater in the diesel cooling system
Oil is usually used in the diesel generator cooling system, and this oil flows throughout the engine and acts as a cooling fluid. To prevent this oil from thickening in cold weather, a heater is usually used in diesel generators. Since this heater is constantly in the circuit, the possibility of its failure is high and it can be one of the things that should be investigated in diesel generator troubleshooting. These heaters are mostly used in cold weather to help start the diesel generator, but in hot weather, it prevents more breakdowns by stabilizing the temperature in the diesel cooling system.
Improper operation of diesel generator cooling system
The failure of the heater in the cooling system causes the oil temperature to decrease and the oil to thicken. As a result of this, the cooling system in the diesel generator does not work well and the temperature increases in the diesel generator. Internal or external leakage in the cooling system also reduces the performance of this system. Leaks usually occur in the heater hose. Some diesel generators sound or turn off special alarms for this error due to improper cooling.
Repairing the cooling system of diesel generators
The temperature of diesel generator combustion is about 2000 degrees Celsius, 35% of the heat generated by diesel fuel is converted into useful work, 31% of it is released through the exhaust, and 10% of it is used to overcome the frictional force of the diesel engine. The combustion residue is about 33%, which has a temperature of about 660 degrees Celsius, which is higher than the melting temperature of internal diesel parts (pistons, valves and bushings), and if the heat is not removed, it will cause them to melt, and also the excessive temperature causes the loss of the oil layer on the parts and burns them. So, the presence of a cooling system in a diesel engine is necessary to absorb this heat and transfer it to the environment. The cooling system in diesel generators, is liquid cooled (water cooled) or air cooled . Both systems have advantages and disadvantages.
The advantages of air-cooled diesel generators are the weight reduction of the device due to the absence of some parts such as water pump, radiator and etc., simpler maintenance, no freezing in cold weather and problems caused by improper water (corrosion or plastering). On the other hand, the disadvantages of air-cooled diesel generators are their temperature control in different conditions and their louder noise.
Battery failure
Diesel generator batteries usually last for four years (more or less). Routine maintenance usually helps to determine the time for to replace the battery.
NOT ON AUTO
In case of “NOT IN AUTO” alarm in the diesel generator or breaker, the device is disconnected or the emergency shutdown chassis is activated. To fix these alarms, the device must be physically reset. (It means that the breaker is connected or the emergency stop button is disabled.)
Repairing the fuel system of diesel generator
The task of this system is to supply the fuel needed by the engine, the pump pumps the fuel from the fuel tank, and after passing through the filter (suspended particles are caught), it enters the injection pump, and the injection pump increases the fuel pressure and injects the fuel with the nozzles installed on the cylinders into the cylinder, and the excess fuel in the nozzles is transferred back to the fuel tank. Adjusting the input fuel (speed adjustment of diesel engines) is done by a device called a governor. One of the advantages of the governor is that it makes the frequency does not change significantly in different loads.
The presence of air in the fuel system
One of the things that must be taken into account in diesel generator troubleshooting, and it is one of the common failures in diesel generators, is the presence of air in the fuel system. Any air bubbles in the injectors will cause the combustion to not happen completely. This disturbance in the injectors of the diesel generator even causes the diesel not to start In old diesel generators, the occurrence of such an event means a leak in the fuel supply system. In new diesel generators, due to the calibration of the fuel system, the negative effect of air is much greater. To prevent this from happening, it is better to start and run the diesel generator for 5 minutes every week.
Diesel generator ventilation method
One of the problems of diesel generators is its ventilation. which causes the diesel generator to turn on late, or not turn on at all. The ventilation method of diesel generator is different according to its type and model. Engines with ECU do not need ventilation, engines with mechanical diesel pumps usually need ventilation when the fuel runs out. To vent there is one or more screws located on the pump or the inlet and outlet hoses of the pump, which must be loosened and the hand pump pumped, to release the air. If the diesel generator does not have a manual pump, we have to raise the level of diesel (by a container) above the level of the engine, and turn the diesel generator on after venting, so that the air trapped in the diesel pump is removed. After airing the diesel generator, check the alarms, if the problem is not solved, seek help from the company’s experts. To solve the venting problem, a fuel level sensor can be installed to shut down the diesel generator before it runs out of fuel.
Repairing the ventilation system of diesel generator
The task of this system is to supply the air needed by the engine; After the air passes through the air filter, its pollution is removed then it enters the turbo charger. A turbocharger is a device that works with the flow of exhaust gases from diesel, and like a compressor, it compresses the incoming air to a certain pressure, which increases the efficiency of the engine. Then the compressed air enters the air manifold and from there it is distributed evenly between the pistons. In some diesel models, heaters are used in the intake air path to heat the intake air, making it easier to start the engine in the cold season.
Environmental and climatic effects
Usually, diesel generators are used in bad weather conditions when the power grid is interrupted, so the location of the diesel generator must be resistant to weather effects. The presence of pests and vermin in the storage area of the diesel generator is also dangerous and will bring the effects of dirt, chewing, etc. To prevent such a problem, the storage place of the diesel generator must be inspected routinely.
The bearings of the device should not be loose. If after checking them, you see that they are loose, you should replace them.
Another reason for the knocking of the engine is wear and tear of the pin. In addition, if the rims are broken, they can cause malfunction of the device and knocking of the engine.
The bottom of the pistons is exposed to soot more than other parts and its pollution may be so high that it causes knocking of the engine. If you notice the presence of soot in this part after troubleshooting the diesel generator, you must clean it.
If the typewriter shafts are damaged, you must replace them. But when buying a part and replacing it, you should pay attention to the originality of the part. Most of the problems that arise in diesel engines are due to the use of low-quality and cheap parts.
The generator should not work more than the specified hours. Because it gets too hot and cannot have proper efficiency. Engine malfunction is one of the most important consequences of overheating.
The reason for the irregularity of the generator engine
Control the lubrication of the gears.
Check the primary pump, check its valves and ventilate the circuit.
Lubricate the gas comb with oil.
Lubricate the regulator shaft first with oil and then with petroleum if it is clogged.
If the regulator axis is too loose, replace it.
Replace the regulator springs if broken.
Coupling control and fuel injection time to be controlled.
Adjust the idle speed with the adjusting screw.
The reason for the low efficiency of the engine
When the load of the device is higher than the standard, we will see a decrease in its efficiency and effectiveness. All diesel engines have a manual in which the instructions for using the device are written. Check its standard load and try not to overload it so that it can perform at its best. Another reason for the decrease in engine efficiency is being out of the regulator or governor, which should be reviewed and adjusted by experts.
The reason for not loading the diesel generator engine
The regulator is not set correctly, and must be readjusted.
Adjust the fuel injection time of the injectors.
The injectors needle ducts are stuck; they must be cleaned or replaced.
The cylinder head gasket is burnt and must be replaced.
Cylinder compression pressure is low, air and smoke valves must be sealed.
The injector needle is not tight inside the injector body, it should be fixed by special tools.
There is air in the fuel line or fuel pump, it must be ventilated
Air and smoke valves close slowly, check spring or valve path.
The reason why the diesel generator engine does not reach the rated speed
The device is overloaded and needs to be adjusted.
The regulator or governor is out of adjustment, and must be reset.
The reason for the high noise of the diesel generator engine
The diesel engine load is higher than its rated load.
The load is not evenly distributed on the cylinders, the engine needs to be readjusted.
The injection time of the injector is not suitable, the injection time of the valves should be adjusted.
If the injector pressure is not adjusted, the injectors should be opened and cleaned, and the pressure of the springs should be adjusted.
Too much valve slack. Check the valve gate, valve guide, and valve stem, and if necessary, replace them.
If the piston is too loose, check the cause of the looseness and replace the ring or piston if necessary.
Overheating of diesel generator engine. Check radiator, coolant, thermostat, flow of engine air intake and exhaust air.
The cause of diesel generator engine boiling
The diesel generator thermostat is defective and must be replaced.
The water filter is dirty and needs to be replaced.
The water pump is broken, repair or replace.
The cooling water level of the diesel generator engine is low, coolant must be added
The reason for the high speed of the diesel engine
The regulator is not set
Sticking or not adjusting the regulator rod
The reason for the reduction of diesel engine power
Clogged or worn out filters
Contaminated or low quality fuel
Defect in the camshaft
Defective injectors
Broken turbo charger
Fuel pump failure
The cause of excessive oil consumption by the diesel generator
Defect in the piston ring
Changing oil viscosity
Defect in the charging seal
Burning engine oil
Valve guide failure
The cause of diesel generator engine failure
The existence of cavitation phenomenon
Defect in the bearings
rise in temperature
The presence of electrical failures
The reason for the low compression pressure of the diesel generator
Stuck valves: Open the valve and hit the stone.
Breaking piston rings: Open and replace the piston rings.
Failure to close the valves: Adjust the valve.
Defects and problems related to the electrical part of the generator
The voltage of the device is lower or higher than normal. In this case, the regulator voltage (AVR) should be checked Failure in this part causes the voltage to go out of the stabilization limit.
The output voltage of the generator is zero. In this case, it may be the burning of the regulator voltage, the diode bridge, the burning of the excitation coil, or the loss of the inductive properties of the generator core.
Generator voltage drop under load. If the excitation winding of the stator or the rotor, as well as the presence of a connection in the output circuit of the generator, the voltage will drop.
Faults related to chassis and coupling
In the diesel generator repairs, the chassis should be checked for points such as air intake in the fuel tank inlet and outlet, tank level failure, fuel tank perforation, loosening of the coupling screws and the connection of the engine to the chassis, and the failure of the shock absorbers can interfere with the proper operation of the engine.
The cause of low diesel generator oil pressure
Contamination of the strainer or oil filter
There is a leak in the oil circuit
Fault in the oil pump
There is looseness in the main bearings
Check the pressure regulating valve.
Repair of diesel generator lubrication system
The oil pump injects the oil in the engine crankcase into the various components of the engine after passing through the oil filter (metal particles and oil water are captured). In some large engines, a cooling radiator is used in the oil flow path.
Diesel generator lubrication system problems and how to fix them
Presence of foam in diesel engine oil
The oil has not been changed on time, and it has been working beyond the standard.
The diesel generator oil level is too low or too high, adjust the oil level.
The oil is not of suitable quality, according to the type of engine, working conditions and weather conditions.
Low oil pressure of the diesel generator engine
Low oil quality and viscosity
The oil filter is dirty.
The oil pressure indicator is broken.
Defective pressure relief or bypass valve.
The internal parts of the oil pump are worn out and need to be serviced or replaced.
The tolerance of crankshafts and bearings has exceeded the standard, the generator diesel engine must be repaired.
High oil pressure of the diesel generator engine
The viscosity of the oil is high, use the right quality oil.
The oil pressure indicator is broken.
The pressure relief or bypass valve is not adjusted (Its spring pressure is too high, adjust the valve spring)
The tolerance of crankshafts and bearings is less than the standard, the diesel generator engine must be repaired
Presence of water in diesel engine oil
The cylinder head gasket is burnt or defective and must be replaced.
The cylinder head is warped, the diesel generator engine needs to be repaired.
If the O-ring around the bush is defective, the diesel generator engine must be repaired.
If there is a hole in the water channel and the oil cooler is leaking, the oil cooler should be repaired or replaced.
The presence of cracks in the water channels inside the cylinder or cylinder head causes leakage, the diesel generator engine must be serviced or repaired.
Check the temperature of the device
In this case, the temperature and condition of the diesel cooling system and the generator should be visited. An increase in the temperature of the device is the same as a fever in the body, and it can be caused by malfunctioning and excessive friction inside the car, it does not matter if this car is a diesel or a generator or any other machine. For this reason, it is necessary to investigate any unusual temperature.
Checking the amount of heat output from the exhaust and that this amount does not exceed the permissible limit.
Visit the inlet air duct to the radiator
There are also a series of electrical inspections that must be checked from the device panel:
Visiting the voltage and current output from the generator as well as the excitation voltage of the generator and that it is normal.
Visiting the active and reactive power of the generator
Checking the output frequency of the generator
Checking the power factor of the generator
The reason for changing the color of engine exhaust smoke:
If there is a problem in the device, the color of the exhaust smoke will change to black, blue and white. Each of these colors are created for the reasons that we mention below. Smoke color detection has a direct impact on diesel generator troubleshooting.
a) black smoke
If the fuel is injected in a large amount in the device, it can cause black smoke in the diesel engine. It is better to check the fuel pump and the amount of fuel. Among other things, we can mention that the air filter is contaminated. The presence of this filter in the device prevents environmental pollution from entering the engine and getting absorbed into the filter.
The filter should be cleaned or replaced every so often to prevent black smoke. If we encounter the smoke valves being loose and completely closed, we should ask a skilled repairman to check and solve the problem. It is possible that due to improper use or wear and tear of the device, after a long period of time, the injectors become blocked and are clogged and combustion does not occur completely in the device, which results in the production of black smoke.
b) Blue smoke
In troubleshooting the diesel generator and finding a reason for the production of blue smoke, we must go to check its oil burning. If the pistons are worn out and need repairs, we will see the production of blue smoke. You should also check the rubbers that are fitted to seal the valve guides.
c) White Smoke
When the compression pressure of the engine is low, we will see white smoke coming out of the exhaust. Parts such as rings and pistons are related to engine compression pressure and should be checked. Otherwise, it may be a problem with faulty injectors.
Diesel generator control system (ECU) repair
The ECU is a very sensitive and expensive piece of equipment, and it is actually the brain of a diesel engine, which is responsible for controlling the injection time of the injectors, the amount of air-fuel mixture, the control of the diesel generator protection sensors, the emission control, as well as the operation of the cooling system, the pump , charger and shaft rotation speed (diesel speed) are monitored. Alternator faults, sudden surges, welding, etc. can damage the ECU, in which case it must be repaired or replaced.
Factors that cause damage to diesel generator ECU:
Disconnecting the battery: This happens if we disconnect the battery from the diesel generator while the diesel charger battery is connected to the electricity. It is one of the main causes of ECU damage, and it may even damage controllers and other equipment. (Before disconnecting the battery, make sure the charger battery is off.)
Fuel solenoid: The solenoid is an electric valve, usually located on top of the fuel pump. and the fuel passes through it. Moisture and corrosion cause a short circuit in its connections. This causes a short circuit in the ECU outputs.
Moisture and dust: Moisture and dust entering the ECU will cause corrosion and damage to the ECU connections, this may not happen after 5 or 10 years.
Inappropriate and defective battery: A bad battery does not have a constant voltage output, and this voltage fluctuation causes damage to the ECU. It is recommended to check the battery periodically.
Starter: If the wrong starter is used when replacing the starter, it may damage the ECU. (Counterfeit starters with sensitive sensors are not required.)
Earth wire problem: The connection of the earth wire in diesel and battery should be visited, disconnecting the earth wire will cause overvoltage, spark, and damage to the ECU.
Welding and lightning: It causes overvoltage and damage to the ECU. Be sure to cut off the ECU power before welding, and make sure that the diesel generator is properly grounded.
Battery to battery: One of the causes is overvoltage and damage to the ECU; avoid battery to battery, disconnect the faulty battery (make sure the battery charger is off when disconnecting the faulty battery), and then replace the healthy battery.
Diesel generator water heater: In some diesel generators, it is installed to keep the cylinder block warm, so that the diesel generator can be started easily in cold weather. When this heater is not properly insulated or grounded, it will cause over 220V voltage to enter the ECU through it, and damage the ECU.
Shock absorber between chassis and diesel: Not having a proper shock absorber will transfer vibration to equipment on the diesel, such as sensors and the ECU, and may damage the ECU’s internal connections.
Defects in valves, sensors, and injectors on diesel: Connecting in any of them will draw a lot of current from the ECU, and damage it.
Alternator: Improper or defective alternator will cause sudden overvoltage and cause damage to the ECU.
Daily visits
Diesel generators should be visited daily in terms of sound condition and abnormal vibrations that may occur in it. It is noteworthy that the sound is an important indicator and those who have experience in repairs can easily understand the malfunction of the device from the change in the sound. Vibration is also a basic indicator, whose abnormal size can indicate a malfunction in the device.
Weekly visits
Visiting the status of diesel engine oil. The oil level can be measured using a dip stick. But to determine the quality of the oil, it is not possible to judge only by the appearance and stickiness of the oil because this work is not very accurate and even repairmen who have years of experience in this work may make mistakes.
The scientific way to do this is to use oil analysis, especially for engines that use a lot of oil, this work is economical. The simpler method is to use the operating hours and kilometers of the engine.
Visiting the Oil Pump and making sure it is healthy
Visiting the diesel tank for any leaks
Radiator water visit: In terms of the water level, as well as its non-leakage and healthy connections, as well as checking the radiator fins that are free of any blocking particles.
Cleaning the diesel engine using air flow, and if it is too dirty, use a car jet and car wash.
Inspection and visit of different parts in terms of not having any drops and oil leaks
If the diesel generator has not been put into service recently, it is necessary to turn it on at least twice a week and run it for half an hour every 7 times in order to make sure that there is no problem and it can work while charging the battery.
Visiting the battery and its connectors as well as controlling the battery water
Monthly visits
Visiting and checking electrical connections and cables for their tightness
Visiting engine and generator base shock absorbers
The resistance of the stator winding or the Megger Test of 1,000 volts should be used for this.
Checking the location of the generator power transmission busbars in terms of being healthy
Lubricating the parts that need greasing and lubrication.
Checking and inspecting air filters and oil filters and replacing them if needed
