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Requirements for safe operation of generator


(1) When the generating set is installed, it should be stable and firm. When operating outdoors, the generator shed should be set up and good ventilation should be maintained.


(2) Oil or other flammable materials shall not be placed nearby, and a fire extinguisher village shall be set up. In case of fire, the power supply shall be cut off and the fire shall be put out immediately.


(3) The connecting parts of the generator shall be firm and reliable, the rotating parts shall be equipped with protective devices, the output lines shall be well insulated, and the indication of each instrument shall be clear.


(4) During the operation, the operator shall not leave the machine. In case of any abnormality, the operator shall stop the machine immediately, find out the cause, and then continue to work after troubleshooting.


Live working is strictly prohibited. Before maintenance of electrical equipment, the power supply must be cut off, and eye-catching warning signs shall be hung, and special personnel shall be assigned for supervision.




Precautions for generator operation


For new or long-term unused generators, strict inspection must be carried out before putting them into normal operation, mainly including winding insulation and wiring.


1. During the operation of diesel generator set, special personnel shall be assigned to monitor and inspect the power, voltage, current, water temperature, oil temperature and oil pressure at any time, and fill in the operation record carefully. It is strictly forbidden to leave the post in series


2. During operation, operators shall keep a safe distance from live equipment and wear labor protection equipment. Attention should be paid to the sequence of switching operation. In case of power failure, the branch switches shall be disconnected first, then the main switch shall be disconnected, and then the switching position of four pole double switch knife switch shall be carried out. In power transmission, the sequence is opposite. During normal shutdown, part of the load should be unloaded first, then the main switch should be disconnected, and finally the diesel engine should be turned off. It is not allowed to disconnect the main switch and cut off the power automatically with the diesel engine flameout. After shutdown, make routine inspection on the unit and record the operation condition (work diary).


3. In case of electric shock, the power switch shall be cut off quickly, or the power supply shall be cut off or disconnected with insulating apparatus. Then rescue, and ask the doctor to the scene rescue. In case of electrical equipment flood, the relevant power supply should be cut off immediately and reported to the local power supply station, and then fire fighting. Dry type fire extinguisher, carbon dioxide fire extinguisher, etc. shall be used for fire fighting of live equipment, and water is not allowed.


4. When the power supply bureau is out of power, first separate the main incoming switch of the power distribution room and the main circuit breaker switch of the generator


5. Check lubricating oil, cooling water, battery power and add enough diesel


6. Turn on the battery switch. Press the electric start operation button. Slowly add oil and speed up to the rated high speed


7. Press the build-up excitation power generation button. Adjust the frequency to 50 cycles, and the output voltage is 380 v


8. Turn on the main circuit breaker of the generator for power transmission after the unit runs for 5 minutes without load


When the power supply bureau calls, the unit stops. First separate the main circuit breaker of the generator, then turn off the throttle and close the main incoming switch of the distribution room.



Technical disclosure of generator operation safety


1. For the generator powered by internal combustion engine, the internal combustion engine part shall be operated in strict accordance with the internal combustion engine operation safety disclosure.


2. For the generator newly installed, overhauled or stopped for more than 10 days, the insulation resistance and absorption ratio of stator and excitation circuit shall be measured before use. The insulation resistance of stator shall not be less than 30% of the value measured last time, the insulation resistance of excitation circuit shall not be less than 0.5mn, and the absorption ratio shall not be less than 1.3, and the measurement record shall be made.


3. Check the transmission part of internal combustion engine and generator before operation, which should be connected reliably, the wire insulation of output line is good, and all instruments are complete and effective.


4. Before starting, put the resistance value of excitation rheostat at the maximum position, then cut off the power supply output main switch and connect the neutral grounding switch. For the unit with clutch, the engine should be started to run without load first, and then the generator can be connected after it is normal.


5. After start-up, check that there is no abnormal noise during the speed-up of the generator, the brush on the slip ring and commutator is in good contact, and there is no jump and spark. When the operation is stable and the frequency and voltage reach the rated value, the power can be supplied to the outside. The load should be increased gradually and the three phases should be balanced.


6. After the generator starts to operate, it should be considered that all electrical equipment has been charged.


7. If the generator voltage is too low, it will have adverse effects on the operation of load (such as electric equipment), the operation of the engine itself, and the stability of grid connected operation; if the voltage is too high, it will not only affect the safe operation of the electrical equipment, but also affect the service life of the generator. Therefore, the maximum and minimum allowable voltage value for continuous operation of generator shall not exceed ± 10% of rated value. The voltage variation range of normal operation shall be within ± 5% of the rated value. If the specified value is exceeded, it shall be adjusted. When the power factor is the rated value, the rated capacity of the generator shall not be changed.


8. When the generator set operates at high frequency, it is easy to damage parts and even cause accidents. When the generator operates at a low frequency, it will not only have adverse effects on the safety and efficiency of electrical equipment, but also reduce the speed of generator and increase the temperature of stator and rotor coil. Therefore, when the generator operates at the rated frequency, its variation range shall not exceed ± 0.5Hz.


9. The power factor of generator shall not exceed 0.95 of late phase (lag). If there is an automatic excitation regulation device, it can operate under the condition of power factor of 1. If necessary, it can operate in the range of 0.95 ~ 1 delay phase for a short time.


10. During the operation of the generator, it is necessary to check and confirm that all instrument indications and operation parts are normal, and adjust the load of the generator at any time. The current of stator and rotor shall not exceed the allowable value.


11. Before shutdown, cut off the main switch of each power supply branch to gradually reduce the load, then cut off the main switch of generator power supply, return the excitation rheostat to the position of maximum resistance, so as to reduce the voltage to the minimum value, then cut off the excitation switch and neutral grounding switch, and finally stop the operation of internal combustion engine.