High and low voltage distribution cabinets play an important role in the power system, but there are obvious differences in many aspects:
- Working voltage
High voltage distribution cabinet
The working voltage is generally 3.6kV and above, and the common ones are 6kV, 10kV, 35kV, 110kV and other different levels. It is mainly used to receive and distribute high voltage electric energy and transmit high voltage power to various power consumption areas or transformers.
Due to the high voltage, the insulation performance and voltage resistance of the equipment are extremely high. During the design and manufacturing process, special insulating materials and structures are required to ensure the safe operation of the equipment under high voltage.
Low voltage distribution cabinet
The working voltage is usually below 1kV, and the common ones are 220V, 380V, etc. It is mainly used to distribute and control the low voltage electric energy output by the transformer to provide power for various low voltage electrical equipment.
Compared with high voltage distribution cabinets, low voltage distribution cabinets have lower voltages and relatively lower requirements for insulation performance, but they also have strict requirements for the reliability, stability and safety of the equipment.
- Structure and composition
High-voltage distribution cabinet
The structure is relatively complex, usually composed of cabinet, disconnector, circuit breaker, transformer, lightning arrester, grounding switch and other main components.
The cabinet generally adopts metal shell, which has good protection performance and mechanical strength. Disconnector is used to isolate the power supply during maintenance, circuit breaker is used to cut off and connect the circuit, transformer is used to measure current and voltage, lightning arrester is used to protect the equipment from the influence of lightning overvoltage, and grounding switch is used to ground the equipment during maintenance to ensure the safety of personnel.
Low-voltage distribution cabinet
The structure is relatively simple, mainly composed of cabinet, circuit breaker, contactor, relay, fuse, instrument and other components.
The cabinet is also mostly made of metal, but its protection level and mechanical strength requirements are relatively low. Circuit breaker is used to protect circuit and equipment, contactor and relay are used to control the on and off of circuit, fuse is used for short circuit protection, and instrument is used to monitor the operating parameters of circuit.
- Functions and uses
High-voltage distribution cabinet
The main function is to receive and distribute high-voltage electric energy, and to control and protect high-voltage circuits. It is usually installed in substations, distribution rooms and other places to provide high-voltage power for large industrial enterprises, power systems, etc.
The operation and maintenance of high-voltage distribution cabinets require professional technicians to strictly abide by relevant safety regulations and operating procedures to ensure the safety of equipment and personnel.
Low-voltage distribution cabinet
The main function is to distribute low-voltage electric energy to various electrical equipment and control and protect low-voltage circuits. It is widely used in factories, shopping malls, office buildings, residential areas and other places to provide reliable power supply for various low-voltage electrical equipment.
The operation of low-voltage distribution cabinets is relatively simple, but it also requires professional personnel to install, debug and maintain to ensure the normal operation of the equipment.
- Protection method
High-voltage distribution cabinet
The protection method is relatively complex, and usually adopts multiple protection methods such as overcurrent protection, quick-break protection, differential protection, and grounding protection. These protection devices can quickly and accurately detect faults, and cut off the faulty circuit in time to protect the safety of equipment and power grids.
The protection device of the high-voltage distribution cabinet generally has high sensitivity and reliability, and can act within milliseconds.
Low-voltage distribution cabinet
The protection method is relatively simple, mainly using overcurrent protection, short-circuit protection, leakage protection, etc. These protection devices can effectively protect low-voltage circuits and equipment, and prevent damage caused by overload, short circuit, leakage and other faults.
The protection device of the low-voltage distribution cabinet generally has good stability and reliability, and can act in a shorter time.
5. Volume and weight
High-voltage distribution cabinet
Due to the high working voltage, complex structure, and large component volume, the volume and weight of the high-voltage distribution cabinet are usually large. Generally, a special distribution room or substation is required for installation, and the requirements for the installation site are high.
The transportation and installation of high-voltage distribution cabinets also require professional equipment and technicians to ensure safety and reliability.
Low-voltage distribution cabinet
The volume and weight are relatively small, and the installation is flexible and convenient. It can be installed indoors or outdoors according to actual needs, and the requirements for the installation site are low.
The transportation and installation of low-voltage distribution cabinets are relatively simple, but you also need to pay attention to safety to avoid damage to the equipment during transportation and installation.
