Switching appliances, measuring instruments, protective electrical and auxiliary equipment are the main components of the distribution box. They are connected according to the requirements of electrical wiring and installed in a closed or semi-closed metal box or screen, which is called the low-voltage distribution box. When the equipment is running, the circuit can be switched on or off manually or automatically. If the equipment fails or does not work properly, you can cut off the circuit or alarm by protecting the electrical appliance. By measuring instrument can display the circuit running parameters, at the same time to adjust some parameters, has deviated from the normal working state of the hint or signal. It is often used in factories, buildings and substation.
1, distribution box manufacturers mainly classified hanging, wall and floor type of the three installation, installation should require the requirements of distribution box.
(1) the box of the iron distribution box needs to do some anticorrosive treatment before installation, first coat the bottom with a layer of paint, and then coat two gray paint.
(2) The iron distribution box needs grounding terminals, the door of the distribution box needs to be opened outwards, and the door should be locked. The outdoor distribution box needs to be sealed, and dustproof and rainproof measures should be taken.
(3) Distribution box is divided into indoor and outdoor two kinds. Indoor distribution box is suitable for offices and production sites, outdoor distribution box is suitable for transformer stations, lighthouses, and other places.
(4) Indoor and outdoor distribution boxes should be made of iron distribution box, iron distribution box should be made of 2mm thick iron plate, distribution box length in 600mm and above the double door. Indoor distribution box is mainly divided into dark type and open type two installation methods.
2. Production and relevant regulations of distribution box manufacturers
(1) Distribution box manufacturing and processing: setting the total isolation switch, shunt leakage circuit breaker, setting the working zero line terminal block, protection zero line terminal block and three-phase five-wire terminal block.
(2) Switch box manufacturing and processing: switch box set total fuse, total isolation switch, branch fuse, branch circuit breaker, three-phase four-line socket and single-phase three-line socket, set working zero line terminal block and protection zero line terminal block.
(3) Switches, energy meters, fuses and other equipment on the power distribution board should be installed vertically, with the upper and lower ends connected with loads, and the phase sequence is consistent.
(4) indoor and external distribution boxes should be equipped with a general switch in front of the watt-hour meter. After the meter, there are generally no more than 4 circuits. Each circuit should be equipped with a separate switch.
(5) The distribution box under the transformer should be made to open the door on both sides (the door opens outwards). In order to facilitate maintenance, the distribution box should be installed on the bracket. The height between the bottom surface of the distribution box and the bottom surface should not be less than 1.2m for connection. The incoming (outgoing) wires of the distribution box should be routed through pipes. The protection pipes should be arranged neatly and painted with black oil. The direction of the cables should be marked on the protection pipes.
(6) Electrical appliances of the power distribution board should be arranged neatly, and the minimum net distance of each accessory should be greater than the specified value.
(7) When the load current exceeds 15.A, current transformers usually need to be installed. The accuracy level of current transformers is above 0.5, and the current transformers need to be installed at the back of the distribution board.
