Why does diesel genset start by battery

The working principle of the battery is to convert chemical energy into electrical energy. The battery used in a diesel generator is generally a maintenance-free battery. Due to its own structural advantages, the consumption of electrolyte is very small, and it is basically unnecessary to replenish distilled water during its service life. It also has the characteristics of shock resistance, high temperature resistance, small size and small self-discharge. The service life is generally twice that of a normal battery.

The role of battery in diesel generator

1. The battery is mainly used to start the diesel engine. There is a starting motor on one side of the diesel engine, which is driven by a direct current (24V) starter motor.

2. It is used to monitor whether the grid and pre-start oil/water conditions meet the starting requirements.

3. Used for excitation (some types of generators require manual excitation after starting).

A diesel generator is equipped with a battery, which is used to start the diesel genset, called a starter battery. The electrolyte is not added when it is delivered to the user, so the electrolyte with specific gravity (1:1.28) should be added before use. First unscrew the top cover of the battery and slowly add the electrolyte as close as possible to the upper scale line. After filling up, please do not use it immediately. Please leave the battery for about 15 minutes.

When charging the battery after filling the electrolyte, the continuous charging should not exceed 4 hours. Too long charging time will cause damage to the service life of the generator battery.

Diesel generator battery storage time is more than 3 months, charging time can be 7 to 8 hours, ambient temperature continues to exceed 30°C or relative humidity continues to be higher than 80%, charging time is 7 to 8 hours, such as battery storage time exceeds one year, the charging time can be 12 hours. When the charging is over, check whether the liquid level of the electrolyte is sufficient. If necessary, add the standard electrolyte with correct specific gravity (1:1.28).

When charging the generator battery, first open the battery filter cap or vent cover, check the electrolyte level, and adjust it with distilled water if necessary. In addition, in order to prevent long-term sealing, the dirt in the battery compartment cannot be discharged in time and the water droplets are prevented from condensing on the inner top wall of the cell. It is necessary to open a special vent hole to facilitate proper circulation of air.

Usually, the battery used in a diesel generator is 24V DC battery. For small power generator set, it often uses 2 batteries. For big power diesel generator, it needs 4 batteries in parallel. If generator starter motor is 12V, then battery required is 12V; if it is 24V, battery is required 24V. When purchasing a generator, the genset control panel should be equipped with a floating-charge device to ensure that the battery is fully charged.

There are different grounding methods for the types of grounding and different circuits. The common grounding methods in electronic power equipment are as follows:

1. Safety ground

The safety ground is to connect the outer casing of the high voltage equipment to the ground. One is to prevent the accumulation of electric charge on the casing, causing electrostatic discharge and endangering equipment and personal safety. For example, the grounding of the computer case, the tail of the tanker dragged on the ground, is to release the accumulated electric charge and prevent accidents. Second, when the insulation of the equipment is damaged and the casing is charged, the protection action of the power supply is prompted to cut off the power supply, so as to protect the safety of the staff, such as the outer casing of the refrigerator and the rice cooker. Third, it can shield the huge electric field of the equipment and play a protective role, such as the protective fence of the civil transformer.

2. Lightning protection grounding

When a power electronic device encounters a lightning strike, whether it is a direct lightning strike or an induced lightning strike, if there is no corresponding protection, the power electronic equipment will be greatly damaged or even scrapped. In order to prevent lightning strikes, we generally set lightning rods at high places (such as the roof and the top of the chimney) and connect with the earth to prevent the safety of equipment and personnel when lightning strikes. Safety grounding and lightning protection grounding are designed to provide safe protection measures for electrical equipment or personnel to protect equipment and personnel.

3. Working grounding

The working ground is a reference potential provided for the normal operation of the circuit. This reference potential is typically set to zero. It can be set to a certain point, a certain section or a block in the circuit system. When the reference potential is not connected to the ground, it is regarded as a relative zero potential. However, this relative zero potential is unstable, it will change with the change of the external electromagnetic field, and the parameters of the system will change, resulting in unstable operation of the circuit system. When the reference potential is connected to the ground, the reference potential is regarded as the zero potential of the earth, and does not change with the change of the external electromagnetic field. However, unreasonable work grounding will increase the interference of the circuit. For example, interference caused by incorrect grounding point, or interference caused by improper connection of the common end of the electronic equipment.

In order to effectively control the circuit to generate various interferences in the work, so that it can comply with the principle of electromagnetic compatibility, when designing the circuit, according to the nature of the circuit, the working ground can be divided into different types, such as DC ground, AC ground, digital ground, analog ground, signal ground, power ground, etc.

Different earthing should be set separately. Don't mix them together in a circuit. For example, digital ground and analog ground can't share a ground line. Otherwise, the two circuits will produce very powerful interference and make the circuit fall into paralysis!

Every diesel generator can’t start without the battery, and the sufficient power of the battery is a necessary condition to ensure the successful start of the diesel generator.