Technical questions and answers of diesel generator sets

What are the conditions for the use of 1 and two generator sets? What kind of equipment is used to complete the work?

Answer: the condition of the parallel machine is that the instantaneous voltage, frequency and phase of the two machines are the same. Commonly known as "three simultaneous"". Complete and complete the work with a special union device. It is generally recommended to use full automatic cabinets. Try not to manually connect the aircraft. Because the success or failure of manual machines depends on human experience. I dare to do electrical work experience 20 years boasted, reliable and successful diesel generator manual machine rate is equal to 0. The power supply system of city TV university can not be applied to the small power system with the concept of manual and parallel machines, because the protection levels of the two are completely different.

2. What is the power factor of the three-phase generator? Can power compensator be added to improve power factor?

Answer: power factor is 0.8. No, because the charge and discharge of the capacitor can cause the fluctuation of the small power supply. Unit oscillation.

3, why do we require customers, units, 200 hours after each operation, to carry out the fastening of all electrical contacts?

Answer: diesel generator sets are vibration work units. Also, many domestic production or assembly units should be useless with double nuts. The use of spring gaskets is useless, once the electrical fasteners loose, will produce a great contact resistance, resulting in abnormal operation of the unit.

4, why the generator room must be clean, no sand ground?

Answer: if the diesel engine inhaled dirty air will make the power decline; if the generator inhaled sand and other impurities, will make the stator and rotor gap between the insulation damage, heavy casualties lead to burnout.

5, why since 2002, our company generally does not recommend that users install neutral grounding?

Answer: 1) the self regulating function of the new generation generator is greatly enhanced; 2) in practice, the lightning fault rate of the neutral grounding unit is on the high side; 3) the quality of grounding is higher and the average user can not do it. Unsafe grounding is not as good as grounding; 4) neutral grounding units will mask leakage faults and ground faults, and these faults and errors can not be exposed in the case of power supply in city rtvu.

6, the neutral point ungrounded units, should pay attention to what problems?

Answer: the 0 wire may be charged because the capacitor voltage between the FireWire and neutral point cannot be removed. The operator shall see the 0 line as a live body. Can not be handled by the electricity market habits.

7, UPS and diesel generators how to power matching, in order to ensure the stability of UPS output?

Answer: 1) UPS is generally used as expressed in the power KVA, it first converted into KW by 0.8 units consistent with the generator active power; 2) if the general generator with active power multiplied by 2 to determine the distribution of UPS generator power, UPS power generator is a power of two times.

3) if using PMG (permanent magnet machine excitation) generator, then to UPS power multiplied by 1.2 to determine the generator power, that is, generator power is UPS, power 1.2 times.

8, indicating the voltage 500V electronic or electrical components, can be used in diesel generator control cabinet?

Answer: No. Because the 400/230V voltage indicated on the diesel generator set is an effective voltage. Its peak voltage is 1.414 times of the effective voltage. That is, the peak voltage of the diesel generator is Umax=566/325V.

9, all diesel generator sets are equipped with self-protection function?

Answer: no.. At present, the market even in the same brand of units, some with, and some without. When buying a unit, the user has to figure it out for himself. The best thing to do is to make written materials as attachments to the contract. General low price machines are not equipped with self-protection function.

10, how to identify counterfeit and shoddy domestic diesel engine?

Answer: first check whether the factory certificate and product certification, they are diesel engine factory "identity certificate" is necessary. Check the number three on the Certificate No. 1) plate number; 2) the body number (in kind, usually in the flywheel machined plane, the font is convex); 3) the oil pump nameplate number. Check the three numbers against the actual number on the diesel engine. You must be accurate. If you find any doubt, you can verify the three serial numbers to the manufacturer.

11, operation electrician took over diesel generator sets, first of all to verify what three points?

Answer: 1) verify the actual useful power of the unit. Then determine the economic power and standby power. The approved method for real power units: diesel engine rated power for 12 hours by 0.9 to get a data (kw), if the generator rated power is less than or equal to the data, with rated power generators for the unit real power, if the rated power generator in the data, you must use the data as true the useful power unit; 2) verification unit with what kinds of self protection function; 3) the power wiring unit to verify whether or not qualified, protective grounding is reliable, three-phase load is basically balanced.

12, there is an elevator starter motor for 22KW, should be equipped with a large generator sets?

Answer: 22*7=154KW (elevator for direct load start type, instantaneous start current is generally 7 times the rated current, in order to ensure the elevator for uniform motion). (that is, at least 154KW generator sets)

13, how is the optimal power (economic power) of the generator set calculated?

Answer: P best =3/4*P rated (that is, 0.75 times rated power).

14, the state stipulates that the engine power of a general generating set should be larger than that of the generator

Answer: 10 percent.

15. The engine power of some generating units is expressed by horsepower