27

2023

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07

How to identify the true and false of diesel generator sets

Author:


General diesel generator sets are mainly divided into four parts: diesel engine, generator, control system and accessories.

1. Diesel engine

The diesel engine is the power output part of the entire unit, accounting for 70% of the cost of the diesel generator set, and it is the link that some unscrupulous manufacturers like to falsify.

1. Deck fake machine

At present, almost all well-known diesel engines in the market have imitation manufacturers. Some manufacturers use these imitation machines with the same appearance to pretend to be famous brands, and use fake nameplates, real serial numbers, and printing fake factory information to make fake names and achieve the goal of greatly reducing costs. . It is difficult for non-professionals to distinguish deck machines.

2. Refurbish the old machine

All brands have refurbished old machines, and it may be difficult for non-professionals to distinguish them.

However, there are still some flaws in the refurbished machine, such as the paint, especially the dead corner paint, which is difficult to be consistent with the original factory.

3. Misleading with similar factory names

These manufacturers are opportunistic. They dare not make decks or refurbish them. They just make a name for themselves in the name of the factory and the name of the diesel engine, and use similar factory names to confuse the name of the diesel engine.

For example, some manufacturers use pinyin or homophones or even the same words to register their own brands, such as: certain Cummins generator set company, KMS generator set, etc. In fact, they have nothing to do with Cummins engines, but only registered certain generators The name of the limited company is just that, and has nothing to do with the "Cummins" trademark. The generator sets with various brands of diesel engines purchased by these manufacturers are all called XX Cummins generators to the outside world.

4. Small horse-drawn cart

Confuse the relationship between KVA and KW. Treat KVA as KW to exaggerate power and sell it to customers. In fact, KVA is commonly used abroad, and KW is the effective power commonly used in China. The relationship between them is 1KW=1.25KVA. Imported units generally use KVA to represent the power unit, while domestic electrical equipment generally use KW to represent, so KVA should be converted into KW with a 20% discount when calculating power.

Don't talk about the relationship between common (rated) power and standby power, just talk about "power", and sell the standby power to customers as normal power. In fact, standby power = 1.1x normal (rated) power. Moreover, the standby power can only be used for 1 hour in 12 hours of continuous operation.

2. Generator part

The function of the generator is to convert the power of the diesel engine into electric energy, which is directly related to the quality and stability of the output power.

1. Stator coil

The stator coils were originally all copper wires, but with the improvement of wire making technology, copper-clad aluminum core wires appeared. Different from the copper-clad aluminum wire, the copper-clad aluminum core wire is copper-clad aluminum when the wire is drawn by a special mold, and the copper layer is much thicker than the copper-plated copper. The use of copper-clad aluminum core wire for the generator stator coil does not have much difference in performance, but the service life is much shorter than that of the all-copper wire stator coil.

2. Excitation method

Generator excitation methods are divided into phase compound excitation and brushless self-excitation. The brushless self-excitation type has become the mainstream with the advantages of stable excitation and simple maintenance, but some manufacturers still configure phase compound excitation type generators in generator sets below 300KW out of cost considerations.

3. Control system

Ordinary standard units need to be switched manually, and it usually takes 10 to 30 minutes from power failure to diesel generator start-up and power transmission.

The automatic control of diesel generator sets is divided into semi-automatic and fully automatic unattended. Semi-automatic is the automatic start of the generator set when the power is cut off, and the automatic stop when the power comes in, which saves the time of starting and stopping, but it still needs manual switching. The fully automatic unattended control panel is equipped with an ATS dual power switch, which directly and automatically detects the mains signal, automatically switches, and controls the automatic start and stop of the generator set at the same time, realizing fully automatic unattended operation, and the switching time can be 3-7 seconds. Tune.

Hospitals, military, firefighting and other places that require timely power transmission must be equipped with fully automatic control panels.

4. Accessories

The standard accessories of regular diesel generator sets are composed of batteries, battery wires, mufflers, shock pads, air filters, diesel filters, oil filters, bellows, connecting flanges, and oil pipes.