Generally, low-voltage electrical appliances are installed and adjusted under normal circumstances. It is not applicable to the installation and acceptance of household appliances, power system protection appliances, electrical instruments, transmitters, computer systems and complete sets of electrical appliances on trays, cabinets and boxes that do not need to be fixed.
The installation of low-voltage electrical appliances shall be carried out according to the approved design.
The transportation and storage of low-voltage electrical appliances shall conform to the relevant national standards; When the product has special requirements, it should meet the requirements of product technical documents.
The storage period of low-voltage electrical equipment and devices before installation is one year or less; When the storage period exceeds, it shall comply with the special provisions on equipment and equipment storage.
The equipment and equipment used shall conform to the current national technical standards, and shall have qualified certificates and nameplates.
After the equipment and equipment arrive at the site, the following acceptance shall be made in time:
Packaging and sealing are better.
The technical documents shall be complete with packing list.
According to the packing list, the specifications and models should meet the design requirements; Accessories and spare parts shall be complete.
Conduct visual inspection according to the requirements of this specification.
Safety technical measures in construction shall conform to the current national safety technical standards and product technical documents.
Construction projects related to the installation of low-voltage electrical appliances shall meet the following requirements:
The construction quality of buildings and structures related to the installation of low-voltage electrical appliances shall conform to the relevant provisions of the current national construction and acceptance specifications. When the equipment or design has special requirements, they should still meet their requirements.
Before the installation of low-voltage electrical appliances, the construction project shall meet the following conditions:
(1) The roof and floor shall be intact without leakage.
(2) Dismantle the templates and scaffolding that hinder the installation of electrical appliances, and clean up the site.
(3) Indoor ground base should be completed, and plastering elevation should be marked on the wall.
(4) The ambient humidity shall meet the design requirements or the provisions of product technical documents.
(5) The doors, windows, walls and decorative sheds of the electrical room, control room and operation room should be completed, and the ground should be polished.
(6) The equipment foundation and framework should reach the strength that allows equipment installation; The quality of welded components should meet the requirements, and the foundation channel steel should be fixed and reliable.
(7) The position and size of embedded parts and reserved holes shall meet the design requirements, and the embedded parts shall be firm.
Before the equipment is installed and put into operation, the construction project shall meet the following requirements:
(1) Doors and windows are installed.
(2) After the operation, the construction work that cannot be carried out and affects the safety operation is completed.
(3) The damaged part of the building during construction should be completely repaired.
Before the equipment is installed and put into operation, the protection work should be done well.
The construction and acceptance of low-voltage electrical appliances should not only conform to the provisions of this specification, but also conform to the current national standards and specifications.
General rule
The inspection before installation of low-voltage electrical appliances shall meet the following requirements:
The nameplate, model and specification of the equipment shall be consistent with the control circuit or design.
The shell, paint layer and handle shall be free from damage or deformation.
Internal instruments, arc extinguishing covers, porcelain parts and bakelite appliances shall be free of cracks or scars.
The screws should be tightened.
For low-voltage electrical appliances with main contacts, the contact of the contacts should be close, with 0.05mm? Check with a feeler gauge of 10mm, and the pressure on both sides of contact shall be uniform.
Accessories should be complete and intact.
The installation height of low-voltage electrical appliances should meet the design requirements; When there is no provision in the design, the following requirements shall be met:
Floor-standing low-voltage apparatus should be 50 ~ 100 mm higher than the ground.
The distance between the center of the operating handle shaft and the ground should be1200 ~1500mm; The distance between the side operating handle and the building or equipment should not be less than 200mm.
The fixing of low-voltage electrical appliances shall meet the following requirements:
Low-voltage electrical appliances can be fixed on walls, columns or other building components with brackets, metal plates and insulating plates according to their different structures. Metal plate and insulation board should be flat; When the rail clamp is used to support the installation, the rail clamp should be matched with low-voltage electrical appliances, and fixed firmly with the wallboard by fixing clips or bolts. It is forbidden to use deformed or unqualified rail clips.
When expansion bolts are used for fixing, bolt specifications should be selected according to product technical requirements; Borehole diameter and embedding depth shall be consistent with bolt specifications.
Fasteners should be galvanized products, bolt specifications should be properly selected, and electrical appliances should be firmly fixed.
Electrical appliances with shock-proof requirements should be equipped with shock-absorbing devices; Locking measures should be taken for fastening bolts.
When fixing low-voltage electrical appliances, the interior of the electrical appliances should not be subjected to additional stress.
The external wiring of electrical appliances shall meet the following requirements:
Wiring shall be made according to terminal marking.
Wiring should be neat, clear and beautiful, and wire insulation should be good and undamaged.
The incoming wire on the power supply side should be connected to the incoming wire end, that is, the fixed contact end; The load side outlet should be connected to the outlet terminal, that is, the movable contact terminal.
The wiring of electrical appliances should use bolts and screws made of copper or metal coated with rust-proof layer, which should be tightened when connecting, and should have locking devices.
External wiring should not cause additional stress inside the electrical appliance.
When the bus is connected with electrical appliances, the contact surface shall conform to the relevant provisions of the current national standard "Code for Construction and Acceptance of Bus Devices in Electrical Device Installation Engineering". Minimum electrical clearance of buses with different phases at the connection.
Low-voltage electrical appliances installed in rows or centrally should be arranged neatly; The distance between equipment should meet the design requirements and be convenient for operation and maintenance.
Outdoor installation of unprotected low-voltage electrical appliances, should have rain, snow and sand intrusion prevention measures.
The zero connection or grounding of the metal shell and frame of electrical appliances shall comply with the relevant provisions of the current national standard "Code for Construction and Acceptance of Grounding Devices in Electrical Equipment Installation Engineering".
The measurement of insulation resistance of low-voltage electrical apparatus shall meet the following requirements:
The measurement shall be carried out in the following parts, and the circuits with different rated working voltages shall be measured separately.
(1) When the main contact is in the off position, it is located between the incoming terminal and the outgoing terminal of the same pole.
(2) When the main contact is in the closed position, between the live parts of different poles, between the contact and the coil, between the main circuit and the control and auxiliary circuit (including the coil) not directly connected with it.
(3) Between the main circuit, control circuit, auxiliary circuit and other live parts and the metal bracket.
The voltage level of megohmmeter used to measure insulation resistance and the measured insulation resistance value shall comply with the relevant provisions of the current national standard "Electrical Equipment Handover Test Standard for Electrical Equipment Installation Engineering".
The test of low-voltage electrical apparatus shall comply with the relevant provisions of the current national standard "Electrical Equipment Handover Test Standard for Electrical Equipment Installation Engineering".
For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd