1)、Eight pitfalls that users should pay attention to when making purchases

1. Confusing the relationship between KVA and KW, treating KVA as KW to exaggerate power and selling it to customers. In fact, KVA is the apparent power, KW is the effective power, and their relationship is IKVA=0.8KW. Imported units are generally represented by KVA as the unit of power, while domestic electrical equipment is generally represented by KW. Therefore, when calculating power, KVA should be converted to KW at a 20% discount.

2. Do not talk about the relationship between the rated power and the backup power of Changxing, only mention one "power", and sell the backup power to customers as Changxing power. In fact, the backup power is 1.1x the long travel power. Moreover, the backup power can only be used for 1 hour during 12 hours of continuous operation.

3. The power of the diesel engine is configured to be the same as that of the generator in order to reduce costs. In fact, the industry generally stipulates that the power of diesel engines is ≥ 10% of the power of generators due to mechanical losses. Even worse, some mistakenly report diesel engine horsepower to users as kilowatts, and use diesel engines with less than generator power to configure the unit, commonly known as "a small horse pulling a big cart", resulting in reduced unit lifespan, frequent maintenance, and high usage costs.

4. Sell the refurbished second mobile phone to customers as a brand new one, and also equip the refurbished diesel engine with a brand new generator and control cabinet, making it difficult for ordinary non professional users to distinguish whether it is a new or old one.

5. Only report the brand of diesel engine or generator, do not report the place of origin, and do not report the brand of the unit. Such as Cummins in the United States, Volvo in Sweden, and Stanford in the United Kingdom. In fact, no diesel generator set can be independently completed by a single enterprise. Customers should understand the manufacturer and brand of the diesel engine, generator, and control cabinet of the unit in order to comprehensively evaluate the level of the unit.

6. Sell the unit without protection function (commonly known as the four protections) to customers as a fully protected unit. Furthermore, it is recommended to sell units with incomplete instruments and no air switches to customers. In fact, the industry generally requires units with a power output of 10KW or above to be equipped with full instruments (commonly known as five meters) and air switches; Large scale units and automation units need to have self four protection functions.

7. Don't talk about the brand grade and control system configuration of diesel engines and generators, don't talk about after-sales service, just talk about price and delivery time. Some also use non power station specific oil engines, such as marine diesel engines and vehicle diesel engines, for generator sets. The quality (voltage and frequency) of the terminal product of the unit cannot be guaranteed. Units that are priced too low generally have problems, commonly known as: only buying wrong, not selling wrong!

8. Let's not talk about the situation of random accessories, such as whether they come with or without silencers, fuel tanks, fuel pipelines, what grade of batteries they come with, what capacity of batteries they have, how many batteries they have, and so on. In fact, these attachments are very important and need to be clearly stated in the contract. Some even do not come with water tank fans, allowing customers to create their own open water tanks.

2)、Unit procurement

When selecting a diesel generator set, full consideration should be given to the comprehensive performance and economic indicators of the diesel generator set, the supplier's professionalism, geographical location, and actual professional level, as well as whether the supplier has after-sales service methods, such as emergency repair vehicles and specialized equipment. Then consider whether the power of the selected unit matches the power of the electricity load. It is generally recommended to select the unit power based on the rated power of the unit x0.8=the power of the electrical equipment. If there are large and medium-sized electric motors, it is also necessary to consider 2-5 times the starting current. If the unit is mainly used for charging UPS, it is necessary to conduct a professional consultation based on the actual situation of UPS, and then determine the rated power of the generator.

3)、Unit installation

Before using the diesel generator set, it should be installed and connected. When installing diesel generator sets, the following precautions should be taken:

1. The installation site should have good ventilation, with sufficient air inlet at the generator end and good air outlet at the diesel engine end. The area of the air outlet should be more than 1.5 times the area of the water tank.

2. The surrounding area of the installation site should be kept clean and avoid placing items that can produce corrosive gases and vapors such as acid and alkali nearby. If conditions permit, fire extinguishing devices should be installed.

3. If used indoors, it is necessary to connect the smoke exhaust pipe to the outside, with a diameter of ≥ the diameter of the smoke exhaust pipe of the muffler. The number of bends in the connected pipeline should not exceed 3 to ensure smooth smoke exhaust, and the pipe should be tilted down 5-10 degrees to avoid rainwater injection. If the exhaust pipe is installed vertically upwards, a rain cover needs to be installed.

When the foundation is made of concrete, its levelness must be measured with a spirit level during installation to fix the unit on a horizontal foundation. There should be dedicated shock-absorbing pads or anchor bolts between the unit and the foundation.

5. The casing of the unit needs to have reliable protective grounding. For generators that require direct grounding of the neutral point, it is necessary for professional personnel to ground the neutral point and equip it with lightning protection devices. It is strictly prohibited to use the grounding device of the mains for direct grounding of the neutral point.

The bidirectional switch between the generator and the mains power needs to be very reliable to prevent reverse power transmission. The reliability of the wiring of the bidirectional switch needs to be inspected and approved by the local power supply department.

7. The wiring of the starting battery needs to be firm

4)、Unit configuration

In addition to the parts provided by the supplier, there are also some optional parts for diesel generators, such as fuel tanks, mains chargers, fuel pipelines, etc. It is essential to know how to choose these accessories. Firstly, the storage capacity of the fuel tank of the unit should be able to provide continuous operation of the unit at full load for more than 8 hours, and it is advisable to avoid refueling the fuel tank during unit operation. Secondly, a dedicated charger with float charging should be selected for the mains charger to ensure that the battery can drive the unit to operate at any time. Try to use rust proof, antifreeze, and anti boiling liquids as much as possible for the coolant. Require the use of diesel engine oil with a CD grade or higher.

5)、The importance of mains power switching switches

There are two types of mains switch: manual and automatic (ATS for short). If your diesel generator is used as a backup power source, you need to install a mains switch at the input point of the power source. It is strictly prohibited to rely on temporary wiring and memory operation methods to input self-contained power to the load. Because once the self owned power supply is connected to the grid without authorization (referred to as reverse power transmission), it will cause serious consequences such as casualties and equipment damage. The correct installation of the switching switch must be inspected and approved by the local power supply department before it can be put into use.