The low-voltage appliances in the distribution box are composed of fuses, AC contactors, residual current action protectors, capacitors and meters. The upper limit of ambient air temperature does not exceed 40℃; The average ambient air temperature for 24h shall not exceed 35℃; The lower limit of ambient air temperature is not lower than 5℃ or 25℃.
The distribution box transformed from rural power grid runs outdoors, which not only generates high temperature by direct sunlight, but also generates heat during operation. Therefore, in the hot summer season, the temperature in the box will reach above 60℃, which greatly exceeds the environmental temperature specified by these appliances.
(3) Drawer switch cabinet. This kind of switchgear adopts a closed shell made of steel plate, and the electrical components of the incoming and outgoing circuits are all installed in drawable drawers, which constitutes a functional unit that can complete a certain type of power supply task. The functional unit is separated from the bus or cable by a grounded metal plate or a functional plate made of plastic to form three areas: bus, functional unit and cable. There are also isolation measures between each functional unit. Drawer switchgear has high reliability, safety and interchangeability, and is a relatively advanced switchgear. Most of the switchgear refers to drawer switchgear. They are suitable for industrial and mining enterprises and high-rise buildings that require high reliability of power supply as centralized control distribution centers.
Distribution box is divided into two types according to the structure.
The construction power distribution system shall be provided with a general distribution box, a sub-distribution box and a switch box, which shall be arranged in a hierarchical manner according to the order of "general separation" and form a "three-level distribution" mode.
(4) Power and lighting distribution control box. Mostly closed vertical installation. Due to different use occasions, the protection level of the shell is also different. They are mainly used as power distribution devices in production sites of industrial and mining enterprises.
Safety of water and electricity is also an important link to realize housing, and the wiring diagram of household distribution box is also essential when installing. The above picture is a few very detailed wiring diagrams.
When the distribution box is faulty or abnormal, cut off the circuit or give an alarm with the help of protective appliances. By means of measuring instruments, various parameters in operation can be displayed, and some electrical parameters can be adjusted to prompt or signal deviations from normal working conditions.
Imported power distribution cabinets are developed abroad and are generally sold in the global power supply and distribution market. Because each country has different requirements and habits for power supply and distribution systems, imported distribution cabinets may not be fully applicable to the domestic market. Moreover, the main electrical components used in imported power distribution cabinets are imported brand products, and some cabinets or some cabinet accessories must be imported from abroad, which causes the price of imported power distribution cabinets to be much higher than that of domestic power distribution cabinets.
The distribution box is responsible for the reasonable distribution of electric energy, which can easily open and close the circuit. It has a high level of safety protection, and can directly display the on-state of the circuit. The wiring of the distribution box is very important, and you must not be careless. If the neutral line and live wire are wrongly connected, it is prone to power accidents.
In the process of home improvement, the laying of home circuit is a crucial link, in which the installation of home distribution box involves the safety of home electricity. The distribution box is a low-voltage distribution device that assembles switchgear, measuring instruments, protective appliances and auxiliary equipment in a closed or semi-closed metal cabinet or screen according to the requirements of electrical wiring. For household distribution box, the shell is not the key, but the electrical components inside are the key. The imported components Schneider and ABB are really easy to use and durable, but the price will be several times that of domestic ones. It is very important to choose a distribution box with guaranteed quality and correct wiring construction.
(2) Failure caused by product quality
According to the purpose of distribution box classification:
(2) Assembly structure: The sheet metal parts are processed separately, and each part is assembled after being processed, and it is reinforced and locked with screws and tees, with beautiful appearance and simple operation, which can save a lot of transportation costs.
Distribution boxes are generally used for household use, while distribution cabinets are mostly used in centralized power supply, such as industrial electricity and building electricity. Distribution boxes and distribution cabinets are complete sets of equipment, distribution boxes are low-voltage complete sets of equipment, and distribution cabinets have high voltage and low voltage.
(3) Faults caused by improper selection of electrical appliances in the distribution box
When the distribution box is in normal operation, the circuit can be turned on or off by manual or automatic switch.
Due to improper selection of AC contactor capacity during manufacturing, AC contactors with the same capacity were installed in different outlet circuits, and the imbalance of three-phase load was not taken into account, so the current grade of some outlet contactors could not be improved by one current grade on the basis of normal selection of models.
(1) Welding structure: simply cut, bend, open holes and weld the sheet metal parts.
Two: distribution box wiring diagram practical home distribution box installation wiring diagram
III. Common faults of distribution box wiring diagram
(1) Failure caused by the influence of ambient temperature on low-voltage electrical appliances
Distribution box, distribution cabinet, distribution board, electrical cabinet, etc. are complete sets of devices for centralized installation of switches, instruments and other equipment.
IV. Wiring Diagram of Distribution Box Classification of Distribution Box
The main feature of domestic distribution cabinets is that the specific models of the same type of distribution cabinets produced by domestic manufacturers are different, and the specific structure of distribution cabinets is also different, but the wiring method of distribution cabinets is the same. Although the technical parameters of domestic distribution cabinets are lower than those of imported ones, they can meet the needs of users in most domestic power supply and distribution systems. The picture above shows Xiaobian sharing two common wiring diagrams of power distribution cabinets.
The wiring diagram of distribution box is so messy that it not only affects the appearance, but also easily leads to electricity accidents.