There are a lot of taboos in the installation of the distribution box and the bad places need everyone's attention, especially in some places we have to pay attention to the installation, because some improper operations may have serious consequences, for the aspects that do not pay attention to, I Also issued some corrective measures to make up for the previous mistakes, together with the small series to see it, look at the distribution box power distribution cabinets and other electrical installations in the manufacturers of some taboos!
First, taboo: lighting distribution box (board) did not check
Consequences: The lighting distribution box (board) has not been inspected, and it is often found after installation: its two-layer board has no special grounding bolts, the protective grounding line has a small cross section, and the openable door with electrical appliances does not use bare copper cord. Reliable connection with metal frame, wire and appliance connection is not strong, there is anti-circle phenomenon, screw mother does not need galvanized parts, wire diameter does not meet the requirements, there is no color mark, no card cabinet and electrical circuit diagram, appliance layout, interval Unreasonable, no N and PE terminal strips are set. Modifying the delay period also affects quality.
Taboo: the lighting distribution box (board) protection line is not in place, the line diameter does not match
Consequences: The protection wires of the lighting distribution box (board) are not arranged from the terminals, but are connected in series by the box frame, the wire diameter is not set as required, and the device with the super-safe voltage of the distribution box door is not provided with the protective ground wire. It is easy to cause a safety accident.
Measures: In accordance with the requirements of the specification, the protective earthing wire busbar shall be provided in the lighting distribution box (board), and the protective earthing wire shall be connected on the busbar.
The cross-sectional area of ​​the protective earthing wire shall not be less than the cross-sectional area from the power source to the largest lead of the electrical appliance; and it shall also be selected in accordance with relevant regulations. The grounding on the distribution box (board) should be secure and must have a loosening device.
An openable door with more than 50V electrical equipment, the movable panel should be reliably connected to a well-grounded metal frame with a bare copper cord. The cross-sectional area of ​​the bare copper cord should also be selected as required. The metal box and the box body with a wall thickness of less than 2.5 mm should not be used as a span of the pipeline. Grounding wire and protective earthing wire crimping point of the electrical appliance.
Second, taboo: the lighting switch box (board) inside the brakes does not indicate the name of the circuit
Consequences: The brakes in the lighting distribution box (board) do not have the name of the circuit, which brings inconvenience to the use and maintenance. If it is mismatched, it is easy to cause a safety accident.
Measures: Generally, according to the requirements of the standard, the wiring system diagram should be attached to the lighting distribution box (board) door, and the name of the circuit should be indicated on the brakes, especially if there is AC, DC or different in the lighting distribution box (board). The level of power supply should have a clear indication. Bring convenience and safety to the work of users and maintenance personnel.
Third, taboo: lighting distribution box, (board) in the electrical equipment, instrument installation is not firm, uneven, the spacing does not meet the requirements
Consequences: The electrical tools and instruments in the lighting distribution box (board) are not installed securely, flattened, and have insufficient spacing, which affects the safety of use.
Measures: The electric tools and instruments on the lighting distribution box (board) should be installed firmly, flat and neat, the spacing should be uniform, the copper terminals are not loose, the opening and closing is flexible, and the parts are complete.
4. Taboo: The detachable metal plate in the lighting distribution box (board) is not connected to the protective grounding system.
Consequences: The detachable metal plate in the lighting distribution box is equipped with various electrical accessories, which are not connected to the protective ground wire and are prone to electric shock.
Measure: The detachable metal plate in the lighting distribution box should have reliable grounding protection. Therefore, the metal plate should be provided with a non-removable special grounding screw, and the protective earthing wire should be effectively connected with it. The wire diameter of the protective earth wire shall be matched according to the specifications and standards to ensure safe use.
5. Taboo: The wiring of the wire in the floor-standing distribution box is too low.
Consequences: The wire pipe mouth laid in the floor-standing power distribution box is too low, which makes it easy for water and debris to enter the pipe and reduce the insulation strength of the wire.
Measures: The wire protection tube in the floor-standing distribution box should be 50-80mm above the base surface of the distribution box. The pipes should be arranged neatly and the nozzles should be flared.
Six, taboo: lighting distribution box (board) using wood materials without flame retardant treatment
Consequences: If the lighting distribution box (board) is used in a damp and dusty place, it is easy to cause mildew and electric leakage. In addition, the wooden box (board) is not subject to flame retardant treatment and is prone to fire, which is an unsafe hidden danger.
Measures: In order to ensure safe use, the lighting distribution box (board) should not be made of combustible materials. Even in dry and dust-free locations, the wooden distribution boxes (boards) used should be flame-retarded before they can be used.
7. Taboo: 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 elevation of the lighting distribution box (board) installation does not meet the requirements, the installation is not firm, the cabinet is not vertical, and the edge of the panel does not cling to the wall when it is concealed, which affects the function of use, and the perception is not good.
Measures: The elevation should meet the design requirements. When the design is not specified, the height of the bottom of the lighting distribution box should be 1.5m. The height of the bottom margin of the lighting switchboard should be 1.8m.
The lighting distribution box (board) should be installed firmly. The allowable deviation of the installation verticality should not exceed 3mm. When concealing, there should be no gap around the distribution box. The surrounding edges of the panel should be close to the wall, and the cabinet should be in contact with buildings and structures. Apply anti-corrosive paint to the parts.
Eight, taboo: the wiring in the lighting distribution box (board) is cross-cluttered, not bundled into bundles
Consequences: The wiring in the lighting distribution box (board) is messy. The two-layer board in the box presses the nozzle, which affects the wire entering the box. If it is barely pushed in, the cable insulation damage will be long and the short circuit will be easily caused. It also makes the inspection inconvenient and affects the perception.
Measures: When using the metal box in the lighting distribution box, it is necessary to prevent rust and corrosion. The outlet hole in the box is not available for electric welding. It is necessary to have one tube and one hole. The metal box hole should be protected before threading.
The lines should be arranged neatly, and the position of the pipe into the box should be reasonably laid out. Do not let the two-layer board press the tube. The wires inside the box should be straight around the box and tied in a neat bundle.
Nine, taboo: N and PE busbars are not set in the lighting distribution box (board)
Consequences: N and PE busbars are not installed in the lighting distribution box (board), and the line cannot be operated safely.
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