Preparation work before test run of diesel generator set

Diesel generator set must be inspected before test run ◎ The steps for inspection before diesel engine test run are as follows: 1) Check whether the surface of the diesel generator set is clean; whether the anchor nuts, flywheel screws and other moving parts nuts are loose, and any problems are found Tighten in time 2) Check whether the clearance of each part is correct. In particular, carefully check whether the clearance of each inlet and exhaust valve and the clearance of the pressure reducing mechanism meet the requirements. 3) Place each cylinder in the decompression position, rotate the crankshaft to check whether there are any abnormal sounds from the operation of each cylinder's parts, and whether the crankshaft rotates freely. At the same time, pump oil into a friction surface, then close the decompression mechanism and shake the crankshaft. Check whether the cylinder is leaking. If it feels laborious when shaking the crankshaft, it means the compression is normal. 4) Check the condition of the fuel supply system. The steps are as follows: Check whether the ventilation hole on the fuel tank cap is smooth. If there is dirt in the hole, clean it. Check whether the added diesel meets the required grade, whether the oil quantity is sufficient, and turn on the oil circuit switch. Open the pressure reducing mechanism and crank the crankshaft. Each cylinder should have a crisp fuel injection sound, indicating good fuel injection. If you hear the sound of fuel injection but no oil comes, there may be air in the oil circuit. At this time, you can loosen the bleed screws of the diesel filter and the fuel injection pump to remove the air in the oil circuit. Check whether there is any oil leakage in the oil pipes and joints, and resolve any problems promptly. 5) Check the condition of the water cooling system. The steps are as follows: Check whether the cooling water in the water tank is sufficient. If the water is insufficient, add enough clean soft water. Check whether there is any leakage in the joint water pipe, and deal with the problem promptly if found. Check whether the impeller of the cooling water pump rotates flexibly and whether the transmission belt is appropriately tight. Check the tightness of the transmission belt and push it with your hand in the middle of the rotating belt. It is appropriate that the transmission belt is pressed down by 10~15mm. 6) Check the condition of the lubrication system. The steps are as follows: Check whether there is oil leakage in the oil pipe and pipe joints, and deal with the problem promptly if any problems are found. Check the amount of engine oil in the oil pan, pull out the dipstick next to the crankcase, and observe whether the height of the oil level meets the regulatory requirements. Otherwise, add engine oil. For diesel engines, add No. 8 or No. 11 diesel engine oil in winter and 14 in summer. No. engine oil. During the inspection, if it is found that the oil level is above the specified height, the reasons for the increase in engine oil should be carefully analyzed. There are usually three reasons: a. When adding engine oil, too much is added. b. Diesel leaks into the crankcase and dilutes the engine oil. c. Cooling water leaks into the engine oil. ③ The oil holes that require manual refueling should be filled with oil and grease using an oil gun. 7) Check the condition of the starting system. The steps are as follows: ① To start the diesel generator set with a point, the steps are a. First check whether the electro-hydraulic specific gravity of the starting battery is within the range of 1.240~1.280. If the specific gravity is less than 1.180, it indicates that the battery is insufficient. b. Check whether the power cord is correct. c. Check whether there is dirt or oxidation on the battery terminals, and polish them clean. d. Check whether the electrical contacts of the starter motor and electromagnetic control mechanism are good. ◎ The installation and inspection steps of the alternator are as follows: 1) When the alternator is coupled to the diesel generator, the parallelism and concentricity of the coupling are required to be less than 0.05mm. In actual use, the requirements can be slightly lower, within about 0.1mm. If it is too large, it will affect the normal operation of the bearing and cause damage. The coupling must be fixed with a positioning pin. The coupling should be retested before installation. 2) When the sliding bearing generator is coupled, the height of the generator center should be adjusted slightly to the center of the diesel engine, so that the weight of the flywheel on the diesel engine will not be transferred to the generator bearing, otherwise the generator bearing will bear additional burden. The weight of the flywheel is not conducive to the formation of oil film on the sliding bearing, causing heat and even burning of the bearing. This type of generator cannot carry any heavy objects on its coupling. 3) When installing the generator, ensure that the cooling air inlet is unobstructed, and keep it away to prevent the hot air from entering the generator again. If there are shutters on the ventilation cover, the windows should face downwards to meet the requirements for the level of protection. 4) When mechanically coupling a single-bearing generator, special attention should be paid to the uniform air gap between the stator and the rotor. 5) According to the schematic diagram or wiring diagram, select the appropriate power cable and use copper connectors for wiring. After the copper connectors are fastened to the busbar and the busbar, the local gap at the joints should not be greater than 0.05mm, and the distance between the conductors should be no more than 0.05mm. Not larger than 10mm, a grounding wire needs to be installed. 6) The wiring terminals in the generator outlet box are marked with U, V, W, and N. This does not mean that the actual phase sequence depends on the direction of rotation. UVW printed on the certificate indicates the actual phase sequence when rotating clockwise, and VUW indicates the actual phase sequence when rotating counterclockwise. 7) If the neutral points of each generator in the power supply system are connected to each other, or the neutral point of the generator is connected to the neutral point of the transformer and its load, the diesel generator set will have a frequency of 3 times the output of the neutral line when running. Get the neutral current. Therefore, the neutral current of the generator must be measured under various load conditions that may occur during operation. In order to prevent the generator from overheating during operation, the line current must not exceed 50% of the rated current of the generator. If the neutral line power is too large, a neutral line reactor should be installed on the neutral line to limit it. 8) The electrical parameters must be adjusted. The frequency of the diesel generator set is generally adjusted to 51.5HZ (mechanical oil pump), the electronic speed-adjustable diesel generator set is generally adjusted to 50.0HZ, and the voltage of the diesel generator set is 400V; 9) Gradual loading In order for the whole machine to run in, the diesel generator set should be loaded step by step. The loading conditions are: 25%, 50%, 75%. Each stage before 75% load should not be less than 30 minutes. According to the diesel generator set Type, can run at 110% load for short periods of time to check the power performance of the diesel generator set; 10) Check the automatic protection function of the diesel generator set: such as low oil pressure, high water temperature, and overspeed, adjust or simulate the above three abnormal conditions, and check the protection and shutdown functions of the diesel generator set. 11) Check whether the diesel generator set has other functions.