Installation of household line and metering and di

Abstract: with the continuous improvement of power consumption level, users have higher and higher requirements for the reliability of power supply. China has a huge low-voltage power network. The quality of low-voltage power construction and the level of operation management will directly affect whether the power supply is safe, economical and reliable, and whether the power can finally be used reasonably

key words: household line measurement and distribution device Untitled Document household line refers to a section of line led from a base pole on the low-voltage power supply line to the first support point outside the user's room. In order to prevent the waw series microcomputer controlled electro-hydraulic servo universal experimental machine produced by barrow instrument from meeting the requirements of gb/t228.1 ⑵ 010 standard, the lead wire is broken or the phase wire is short circuited with the neutral wire, The regulations require that the household line and neutral line should be introduced from the same base pole, and should not be introduced from any point between spans. 1. Requirements for low-voltage household lines (1) during the installation and construction of household lines, it is often necessary to cross buildings, streets and other lines. In order to protect the safe and reliable power supply, it must comply with the provisions of Table 1. Table 1 requirements for the installation of household lines. The minimum distance (m) of the objects crossed by the household lines crosses the open streets. 6 crosses the streets and sidewalks that are difficult to open to traffic. 3.5 crosses Li, Nong and Xiang. 3 crosses the balconies, platforms and building roofs. 2.5 and communications Broadcast line crossing 0.6 away from the roof 0.6 above the window 0.3 under the window or balcony railing 0.8 horizontal distance from the window or balcony 0.75 horizontal distance from the wall or framework 0.05 (2) during the installation and construction of household lines, the distance between lines of low-voltage household lines and the minimum section of household lines must comply with the relevant provisions of Table 2. Table 2 requirements for connecting household lines: additional ways: bar distance (m) span distance (m) distance between lines (CM) copper wire (mm2) aluminum wire (mm2) free rod up and down 25 and below 10 and below 15 2.5 4.0 25 and above 10 ~ 25 24.0 6.0 laying along the wall 6 and below 6 and below 10 2.5 4.0 6 and above 15 (3) power and lighting power of interconnected houses in the same building, each unit of multi-storey residence, and a unit in the same enclosure, Only one entry point is allowed. (4) The entry point should be as close to the power supply line and load center as possible. (5) The entry point shall be below the point of connection and the distance shall not be greater than 0.5m. The building at this point shall be firm and free from rain and snow, and shall be convenient for installation and maintenance to ensure construction safety. The working environment of the spring fatigue testing machine and the normal protection of the equipment (6) should be consistent with the entrance curtain wall and large window wall system PNAP 106:1998 household points of adjacent buildings, including buildings that conform to the coaxiality of the frame. 2 installation of incoming line (1) the incoming line must adopt copper core or aluminum core insulated wire with good insulation, and copper wire is preferred; No contact is allowed in the middle of the incoming line. (2) When the incoming line passes through the wall, it should be covered with porcelain pipe, steel pipe or plastic pipe. (3) The incoming line shall be of sufficient length during installation, and the indoor end is generally connected to the main fuse box. After the outdoor end is connected with the wiring user, the sag shall be maintained at 200mm, and the outdoor length shall not be less than 800mm. 3 installation requirements of metering and distribution devices (1) requirements of installation site: it should be avoided to install in places prone to natural, high temperature, humidity, shock or dust, otherwise it will affect the insulation, connection, heat dissipation and accuracy of metering of electrical equipment, and even cause fire. Power users should have a special distribution room or switchboard, and the room should be kept clean. At the same time, the room should have appropriate ventilation conditions and sufficient lighting. If accessories are installed in the production workshop, fences should be installed around them. The fence shall be kept at least 0.8m away from the most prominent part of the general power distribution device to avoid accidental touch and accidents. (2) Requirements for installing the electric energy meter box and distribution board: ① the electric energy meter should be installed on the electric energy meter box or distribution board, and the electric energy meter should be installed perpendicular to the ground. ② The size of electric energy meter box or distribution board shall be determined according to the required area of different electric energy meter boxes and main switches. ③ The distribution board or electric energy meter box can be installed in the open or in the dark, but when conditions permit, it should be installed in the dark as far as possible. During installation, the bottom cabinet of distribution board or electric energy meter box is embedded in the wall during civil construction, and the surface frame is configured after the completion of civil decoration. ④ The distribution board or meter box set on the wall should be installed firmly and reliably, and its installation height is usually about 1.8m above the ground at the lower edge of the meter box. (3) Regulations on the selection of the main switch of low-voltage users: the main switch in the distribution device of low-voltage users should be selected according to the nature and capacity of the power load. Generally, the main switch can be selected by itself. With the continuous improvement of power consumption level, users have higher and higher requirements for the reliability of power supply. China has a huge low-voltage power network. The quality of low-voltage power construction and the level of operation and management will directly affect whether the power supply is safe, economic and reliable, and whether the power can finally be used reasonably