Taboo 1: The lighting distribution box (board) enters the site without inspection.
Consequences: The lighting distribution box (board) is not inspected when it enters the site. It is often found after installation: its two-layer board does not have a special grounding bolt, the cross-section of the protective ground wire is small, and the openable door equipped with electrical appliances does not use bare copper cords Reliable connection with metal frame, weak connection between wire and appliance, reverse loop phenomenon, screw nut does not need galvanized parts, wire diameter does not meet the requirements, not marked by color code, no card cabinet and electrical circuit diagram, appliance layout, spacing It is unreasonable, no N and PE terminal blocks are set, and the delayed construction period will also affect the quality.
Measures: First, when processing orders, the manufacturer should submit technical requirements that meet the design and specification standards. The manufacturer should make samples, and then produce after acceptance; and check and accept the products in strict accordance with the design and specification standards when the product enters the site. , And then install it after confirming the qualification.
Taboo 2: Use wooden materials that have not been flame-retardant for lighting distribution boxes (boards).
Consequences: If the lighting distribution box (board) is used in a humid and dusty place, it is easy to mold and leak; in addition, if the wooden box (board) is not treated with flame retardant, it is easy to cause fire and is an unsafe hazard.
Measures: To ensure safe use, it is required that the lighting distribution box (board) should not be made of combustible materials. Even in a clean and dust-free place, the wooden power distribution box (board) used should be flame-retardant before use.
Taboo 3: The lighting distribution box (board) is not installed firmly, and the elevation does not meet the requirements. When concealed, the edges of the panel are not close to the wall.
Consequences: The installation elevation of the lighting distribution box (board) does not meet the requirements, the installation is not firm, the box body is not vertical, when concealed, the edges of the panel are not close to the wall, affecting the use function, and the look and feel is not good.
Measures: The elevation should meet the design requirements. If the design is not specified, the height of the bottom edge of the lighting distribution box from the ground should be 1.5m. The height from the bottom of the lighting switchboard to the ground should be 1.8m. The lighting distribution box (board) should be installed firmly, and the allowable deviation of installation verticality should not be greater than 3mm. When concealed installation, there should be no gaps around the distribution box, the edges of the panel should be close to the wall, and the box should be in contact with buildings and structures. Anticorrosive paint is applied to the parts.
Taboo 4: The lines in the lighting distribution box (board) are crossed and messy, not tied into a bunch.
Consequences: The wiring in the lighting distribution box (board) is messy, and the two-layer board in the box tightly presses the nozzle, which affects the wire entering the box. If it is reluctantly squeezed in, the wire insulation will be damaged for a long time, which may easily cause a short circuit. And make maintenance inconvenient and affect perception.
Measures: When metal boxes are used for lighting distribution boxes, rust and corrosion protection should be done. The outlet hole in the box cannot be opened by electric welding. One hole is required for one pipe. The metal box hole must be protected before threading. The lines should be arranged neatly, and the positions of the pipes in the box should be reasonably arranged. Do not let the two-layer board tightly press the pipes. The wires in the box should be coiled straight around the box and tied into a neat bundle.
Taboo 5: Do not set N and PE busbars in the lighting distribution box (board).
Consequences: N and PE bus bars are not installed in the lighting distribution box (board), and the safe operation of the line cannot be guaranteed.
Measures: In the lighting distribution box (board), the neutral wire (N wire) and the protective earth wire (PE wire) busbars should be set respectively. There are numbers.
Taboo 6: The wiring of the spiral fuse installed in the lighting distribution box (board) is incorrect.
Consequences: The screw fuse installed in the lighting distribution box (board) is incorrectly wired. Connect the power cord to the screw terminal, which affects the replacement of the fuse, and improper operation can easily cause electric shock.
Measures: To ensure safety, the power cord of the screw fuse installed in the lighting distribution box (board) should be connected to the terminal of the middle contact, and the load line should be connected to the screw terminal.
Taboo 7: The protection line of the lighting distribution box (board) is not in place, and the wire diameter does not meet.
Consequences: The protection wires of the lighting distribution box (board) are not arranged from the terminals, but are connected in series by the box structure. The wire diameter is not set as required. The devices with ultra-safe voltage on the door of the distribution box do not have a protective ground wire. Easy to cause safety accidents.
Measures: According to the requirements of the specification, a protective ground wire bus should be installed in the lighting distribution box (board), and the protective ground wire should be connected to the bus bar. The cross-sectional area of the protective ground wire should not be less than the cross-sectional area from the power supply to the largest lead wire of the electrical appliance; it should also be selected according to relevant regulations. The grounding on the distribution box (board) should be firm and good, and there must be an anti-loose device. For openable doors equipped with electrical equipment exceeding 50V, the movable panel shall be reliably connected to a metal frame with good grounding by bare copper cords. The cross-sectional area of bare copper cord should also be selected according to regulations. The metal box and box body with a wall thickness of less than 2.5mm should not be used as the crimping point of the grounding wire of the pipeline and the protective grounding wire of the electrical appliance.
Taboo 8: The brakes in the lighting distribution box (board) are not marked with the circuit name.
Consequences: The brakes in the lighting distribution box (board) are not marked with the circuit name, which will cause inconvenience to use and maintenance. If the brakes that should not be closed are mistakenly closed, it is easy to cause safety accidents.
Measures: Generally, according to the requirements of the standard, the wiring system diagram should be affixed in the door of the lighting distribution box (board), and the circuit name should be marked on the gate, especially if there is AC, DC or different in the lighting distribution box (board) The level of power supply should have obvious signs. Bring convenience and safety to the work of users and maintenance personnel.
Taboo 9: Lighting distribution boxes, electrical appliances and meters in the (board) are not firmly installed, uneven, and the spacing does not meet the requirements.
Consequences: The electrical appliances and meters in the lighting distribution box (board) are not firmly installed, flat, and spaced, which affects the safety of use.
Measures: The electrical appliances and meters on the lighting distribution box (board) should be installed firmly, smoothly and neatly, with uniform spacing, no loose copper terminals, flexible opening and closing, and complete parts.
Taboo 10: The wires in the lighting distribution box (board) are not threaded according to the color code.
Consequences: If you do not thread the wires according to the color code, when using a single-phase circuit, it is difficult to identify the three-phase power supply, and it is difficult to balance the load, causing serious three-phase imbalance. When using three-phase equipment, there is no color It is easy to mix the phase sequence when wiring, and it is difficult to grasp the direction of rotation when some equipment requires a fixed steering.
Measures: In order to ensure safety and convenient construction, the wires in the lighting distribution box (board) can pass through the trunk line in the pipe according to the regulations. The main line can not be separated, but the main circuit of the line pipe nozzle to the main switch of the distribution box (board) and each The electric branch should be separated according to the color code requirements. In this way, when a single-phase circuit is used, the load can be better balanced, and when a three-phase power supply is used, the wiring should be connected according to the phase sequence to ensure the normal operation of the equipment.
Taboo 11: The detachable metal plate in the lighting distribution box (board) is not connected to the protective grounding system.
Consequence: The detachable metal plate in the lighting distribution box is equipped with various electrical accessories, and the protective ground wire is not connected, which may easily cause electric shock accidents.
Measures: The detachable metal plate in the lighting distribution box should have reliable grounding protection. Therefore, it is required that the metal plate should be provided with a non-detachable special grounding screw, and the protective grounding wire should be effectively connected to it. The wire diameter of the protective ground wire should be configured according to the specifications and standards to ensure safe use.
Taboo 12: The location of the lighting distribution box in the shaft is improper.
Consequences: The lighting distribution box is located in the shaft. Since there are generally strong and weak currents in the shaft, and the space is very small, it is not easy to operate, and a little carelessness may easily lead to safety accidents.
Measures: After receiving the drawings, the drawings should be carefully reviewed. If the layout of the electrical pipes and boxes in the shaft is found to be unable to meet the requirements of the specification and standards, it should be put forward during the design submission. It is generally required that no less than o should be left in front of the lighting distribution box and terminal box in the electric shaft. 8m operation and maintenance distance. In order to prevent the interference of strong electricity to weak electricity, the strong electricity and the weak electricity are arranged on both sides of the shaft or isolation measures are taken.
Taboo 13: The wiring and pipeline in the floor-mounted distribution box are laid too low.
Consequences: The nozzles of the wires and pipes laid in the floor-mounted distribution box are too low, which will easily allow water and debris to enter the pipes and reduce the insulation strength of the wires.
Measures: The wire protection pipe in the floor-mounted distribution box should be 50-80mm higher than the base surface of the distribution box. The pipelines should be neatly arranged, and the nozzles should be flared.
Taboo 14: All metal accessories in wiring and electrical installation lighting engineering are neither galvanized nor anticorrosive.
Consequences: The metal accessories are not galvanized or do not have anti-corrosion treatment, which is very easy to corrode and shorten the service life.
Measures: In order to ensure the quality of the project and extend the service life, metal accessories such as pipe clamps, brackets, hooks, pull rings and box (box) bolts, nuts and other ferrous metal accessories used in wiring and electrical installation lighting projects are required. All should be galvanized or coated with anticorrosive paint.
