The design and installation of electrical control cabinets should follow the following standards

GB1207-1997 Voltage Transformers
GB1208-1997 Current Transformers
GB13539.1-2002 Low voltage fuses Part 1: Basic requirements

GB 13539.2-2002 Low voltage fuses - Part 2: Supplementary requirements for fuses used by dedicated personnel (mainly for industrial fuses)

GB 13539.3-1999 Low voltage fuses - Part 3: Supplementary requirements for fuses used by unskilled personnel (fuses mainly used for household and similar purposes) GB13539.4-1992 Low voltage fuses - Supplementary requirements for fuses used for the protection of semiconductor devices

GB/T14048.1-2000 General Principles for Low Voltage Switchgear and Control Equipment
GB/T14048.2-2001 Low voltage switchgear and control equipment - Low voltage circuit breakers

GB/T 14048.3-2002 Low voltage switchgear and control equipment - Low voltage switches, isolators, isolating switches, and fuse assemblies
GB/T 14048.4-2003 Low voltage switchgear and control equipment - Low voltage electromechanical contactors and motor starters

GB/T 14048.5-2001 Low voltage switchgear and control equipment - Part 5-1: Control circuit appliances and switching elements - Electromechanical control circuit appliances

GB/T 14048.6-1998 Low voltage switchgear and control equipment - Contactors and motor starters - Part 2: AC semiconductor motor controllers and starters - GB/T 14048.7-1998 Low voltage switchgear and control equipment - Auxiliary electrical appliances - Part 1: Terminal blocks for copper conductors

GB/T 14048.8-1998 Low voltage switchgear and control equipment - Auxiliary electrical appliances - Part 2: Protective conductor terminal blocks for copper conductors

GB/T 14048.9-1998 Low voltage switchgear and control equipment - Multi functional electrical appliances (equipment) - Part 2: Control and protection switchgear (equipment)

GB/T 14048.10-1999 Low voltage switchgear and control equipment - Control circuits, electrical appliances and switching components - Part 2: Proximity switches

GB/T 16935.1-1997 Insulation Coordination of Equipment in Low Voltage Systems Part 1: Principles, Requirements, and Tests

GB 7251.1-2005 Low voltage switchgear and control equipment - Part 1: Type testing and partial type testing - Complete sets of equipment

GB 7251.2-1997 Low voltage switchgear and control equipment - Part 2: Special requirements for busbar trunking systems (busbar ducts)

GB/T 4026-1992 Identification and Application of Wiring Terminals and Specific Wire Terminals for Electrical Equipment - General Rules for the Alphabet Numeric System

GB/T4942.2-1993 Degrees of protection for low-voltage electrical enclosures

GB4208-1993 Housing protection level (IP code)

The above listed standards are not all standards, they only indicate the main standards

1、 Process preparation before assembly

1. The structure should meet the requirements of the product structure of this model, and the product should have fixed installation holes.

2. The door should be able to rotate flexibly within an angle greater than 90 degrees. During the rotation process, the paint film should not be damaged, and electrical components should not be impacted. There should be no obvious shaking after the door lock is closed.

3. The welding of the shell should be firm, and the weld seam should be smooth and uniform. There should be no welding penetration, cracks, undercuts, slag splashing, pores, etc. The welding flux should be removed completely. After the surface treatment of the shell, the paint film surface should be full, bright in color, uniform in color, smooth and even, without visible defects such as brush marks, wrinkles, pinholes, blisters, scars, spots, fingerprints, repair marks, and mechanical impurities.

4. All electroplated parts on the product (including the electroplated parts and fasteners of the components themselves) must not have peeling, peeling, blackening, rusting, or other phenomena.


2、 Component selection and installation

1. The electrical components and materials selected within the product must comply with the requirements of the certified product and drawings. On the premise of not affecting the internal quality requirements of the product, consent can be obtained and relevant approvals can be obtained for substitution within the scope of certification regulations.

2. Components must use qualified products produced by manufacturers who have obtained mandatory product certification, and non certified products are not allowed to be used.

3. All indicator lights and button colors on the product should comply with the provisions of GB/T4025-2003, or comply with the schematic or wiring diagram.

4. All components should be installed and used according to their manufacturing regulations, with a tilt of no more than 5 °. It is necessary to ensure that the arc of the switch does not harm the operator. For manually operated components, the operating mechanism should be flexible and free of jamming.

5. All components should be firmly fixed on the framework or bracket, and each component should be marked with a prominent symbol. The symbol or code used must be consistent with the schematic or wiring diagram.

When connecting the ends of auxiliary circuit wires to components, a wire number tube must be worn, and the label should be correct, clear, complete, firm, and have permanent adhesion. The label must be consistent with the wiring diagram number.

7. The installed components should be easy to operate, not obstructed by space during operation, and should not touch charged objects.

8. The arrangement of electrical components, units, and external wire terminals installed on the same bracket (mounting plate, mounting frame) should be easy to access during installation, wiring, maintenance, and replacement. Especially, the external wiring terminals should be located at least 0.2m above the foundation surface of the ground mounted complete equipment, and the installation of the terminals should make it easy for the cables to connect to them. The components that must be adjusted and reset within the complete equipment should be easily accessible. For ground mounted complete sets of equipment, indicator instruments observed by operators should not be installed at a height of 2 meters above the foundation surface of the complete set of equipment. Operating devices, such as handles, buttons, etc., should be installed at a height that is easy to operate; The centerline should not be higher than 2m above the foundation surface of the complete set of equipment.

9. Switching devices and components should be installed in accordance with the manufacturer's instructions (operating conditions, arc distance, distance of arc separation plate movement, etc.) to meet the requirements of the electrical component product manual, such as arc distance, electrical clearance, and creepage distance.

10. Ensure the production and installation distance of the primary and secondary wires. The heating element should be placed above the switchgear and kept at a certain distance from the insulated wire.

11. The assembly of the same batch of products should be consistent.

12. Install the components or accessories on the corresponding brackets or mounting plates, and then install the brackets or mounting plates on the box body; Or directly installed on the box. After accurately measuring and adjusting the installation position, tighten it and do not hit the components and electrical components heavily during adjustment.

13. The protective layer of fasteners and metal parts used for assembly shall not fall off or rust. The selection of screws should match the holes on the components. After tightening, the screw protrudes 3-5 pitches from the nut, and the tightening torque of the bolt.

14. During assembly, grounding continuity should be fully considered. If any two metal components inside the box are connected by bolts and there is an insulation layer, corresponding specifications of grounding washers should be used. Attention should be paid to contacting the tooth surface of the grounding washer with the surface of the components to scratch the insulation layer.

15. When installing components that are prone to damage due to vibration, rubber pads should be added between the components and the mounting plate for shock absorption.

16. For components with operating handles, they should be adjusted in place without any jamming.

17. After assembly, install all the fasteners, fuse cores, switch covers, handles, arc extinguishing covers, etc. that have been removed from the components.

18. Various protective boards should be installed in place.

19. After the assembly of electrical components, the electrical clearance and creepage distance should comply with relevant regulations.