1.Q: What are the conditions for two generator sets to be used together? What devices are used to perform parallel work?
A: The condition of parallel use is that the voltage, frequency and phase of the two machines are the same. Commonly known as “three simultaneous”. Use a special parallel device to complete the parallel work. It is generally recommended to use fully automatic cabinet combination. Try not to manually parallel the machine. Because the success or failure of manual parallel depends on human experience. With more than 20 years of experience in electric power work, the author boldly states that the reliable success rate of manual parallel operation of diesel generators is equal to 0. The small power supply system can not be applied to the concept of manual parallel power supply system, because the protection level of the two is completely different.
2.Q: What is the power factor of a three-phase generator? Can a power compensator be added to increase the power factor?
A: The power factor is 0.8. No, because the charge and discharge of the capacitor will cause fluctuations in the small power supply. And unit oscillation.
3.Q: Why do we require our customers to perform a tightening of all electrical contacts after every 200 hours of operation?
A: Diesel generator sets are vibration workers. And many domestically produced or assembled units should use double nuts of no use. The use of spring gaskets is useless, once the electrical fasteners are lax, it will produce a large contact resistance, resulting in abnormal operation of the unit.
4.Q: Why must the generator room be clean and free of floating sand?
A: If Diesel engine inhaled dirty air it will reduce power; If the generator inhales impurities such as sand particles, the insulation between the stator gap will be destroyed, and the heavy one will burn.
5.Q: Why since 2002, our company generally does not recommend that users use neutral grounding during installation？
A: 1) The self-regulation function of the new generation of generators is greatly enhanced;
2) In practice, it is found that the lightning failure rate of the neutral grounding unit is high;
3) High grounding quality requirements, ordinary users can not do. Unsafe working grounding is better than no grounding;
4) The neutral grounded unit will cover the load of leakage faults and grounding errors, and these faults and errors can not be exposed in the case of high current power supply.
6.Q: What problems should be paid attention to when using the neutral ungrounded unit?
A: Line 0 May be charged because the capacitive voltage between the fireline and the neutral point cannot be eliminated. The operator must treat line 0 as live. Can not be handled according to the mains habit.
7.Q: How to match the power of UPS and diesel generator to ensure the stability of UPS output?
A: 1）UPS is generally expressed by the apparent power KVA, which is converted by 0.8 into a unit KW consistent with the active power of the generator;
2) If the general generator is used, the active power of the UPS is multiplied by 2 to determine the assigned motor power, that is, the generator power is twice the UPS power.
3) If the generator with PMG (permanent magnet excitation) is used, the power of the UPS is multiplied by 1.2 to determine the generator power, that is, the generator power is 1.2 times the UPS power.
8.Q: Can electronic or electrical components with a voltage of 500V be used in diesel generator control cabinets？
A: You can’t. Because the 400/230V voltage marked on the diesel generator set is the effective voltage. The peak voltage is 1.414 times of the effective voltage. That is, the peak voltage of the diesel generator is Umax=566/325V.
9.Q: Are all diesel generator sets equipped with self-protection?
A: Not really. At present, some units with or without the same brand are even on the market. Users have to figure it out for themselves when buying units. It is best to make written materials as attachments to the contract. Generally, low-cost machines do not have self-protection functions.
10.Q: How to identify fake domestic diesel engines?
A: First check whether there is a factory certificate and product certificate, they are the diesel engine factory “identity”, is a must have. Check the three serial numbers on the certificate again 1) the nameplate number; 2) The body number (in kind, it is generally on the plane machined by the flywheel end, and the font is convex); 3) Oil pump nameplate number. These three numbers and the actual number on the diesel engine check, must be accurate. If any doubt is found, these three numbers can be reported to the manufacturer for verification.
Post time: May-27-2024