What Is an Electric Switchboard?

Switchboards, also known as power distribution cabinets, are devices that concentrate, switch, and distribute electrical energy. The switchboard is generally composed of a cabinet, a switch (circuit breaker), a protection device, a monitoring device, an electric energy meter, and other secondary components. Installed in power stations, substations, and customers with large electricity consumption.

The switchboard usually consists of a cabinet, a switch, a protection device, an electric energy meter, and other secondary components. The main purposes are: to facilitate power failure and power transmission, to play a metering and protection role and function, to facilitate maintenance when a circuit failure occurs. The switchboard can be used alone or as a complete set of mechanical equipment. With the increase of requirements for various mechanical equipment, the processing and manufacturing of switchboards are also constantly improved. At present, the switchboard industry is a mature industry; the quality of switchboards has also been greatly improved due to the upgrade of electrical components and the improvement of machining levels ^[1]

The main causes of fire in the switchboard are: the wiring of the switchboard is not in good contact with electrical appliances, meters, etc., causing

1 Model development and current status

At the end of the last century, domestically launched BFC, GCL, GCK, GCS and other pull-out switch cabinets. Later, MNS models were introduced to accommodate small circuit breakers. In this way, up to four small circuit breakers can be installed in one drawer, saving drawers Other models were introduced.

2 Withdrawable switchgear consisting of connector --- dynamic and static contacts

The advantage of the withdrawable switchgear is that drawer switches of the same specifications can be interchanged and can be replaced immediately when the switch fails. However, there are also disadvantages-if the static contact fails, it cannot be replaced. Such failure generally occurs during use time. On longer or over-current drawers. High-current drawers exceeding 300A should be checked carefully, as shown in Figure 1. If the hair of the static contact is hot, the spring of the static contact will lose its elasticity, and the static contact can be burned, which can seriously cause an arc short circuit between phases.

3 Power distribution screen consisting of withdrawable switches

The power distribution screen composed of withdrawable switches is more reliable because the withdrawable switches are integrated; generally more than 600A is used, and some units require more than 400A to use withdrawable switches; I think it is better to use withdrawable switches over 400A, otherwise It is very easy to go wrong. I have encountered such examples several times ^[1] .