1. The electrical equipment should have enough electrical clearance and creepage distance to ensure the safe and reliable operation of the equipment

2. For the installation structure of electrical components and their assembly plates, the front disassembly and assembly shall be considered as far as possible.

3. If possible, the installation fasteners of components should be made to be able to fasten and loosen the brackets on the front.

4. All electrical components can be disassembled and replaced separately without affecting the fixation of other components and wire bundles.

5. The heating element should be installed in a place with good heat dissipation, and the connection between the two heating elements should be made of heat-resistant wire or bare copper wire covered with porcelain tube.

6. Diodes, triodes, thyristors, silicon stacks and other power semiconductors should be installed vertically on their heat dissipation surfaces or air ducts of heat sinks to facilitate heat dissipation.

7. Resistor and other electric heating elements should be installed above the box. The installation direction and position should be considered to be conducive to heat dissipation and minimize the thermal impact on other elements.

8. The electronic components in the cabinet shall be arranged as far away from the main circuit, switching power supply and transformer as possible, and shall not be placed directly or close to the convection direction of other heating components in the cabinet.

9. The arrangement of master control electrical components and setting electrical components should avoid the possibility of misoperation or action value change due to accidental touch of its handle and button. Generally, the setting device should be locked with double nuts and sealed with red paint after setting to avoid movement.

10. Fuses of system or circuits with different working voltages shall be arranged separately.

11. Fuses and parts which are easy to be damaged in use and need to be adjusted and reset occasionally shall be accessible without dismantling other parts for easy replacement and adjustment.

12. The installation position and distance between fuses shall facilitate the replacement of melt.

13. Fuses of different voltage levels shall be arranged separately, and staggered mixed arrangement is not allowed.

14. For fuse with fuse indicator, the indicator shall be installed on the side convenient for observation.

15. When the porcelain fuse is installed on the metal base plate, its base shall be padded with soft insulating gasket.

16. When the low-voltage circuit breaker is used together with the fuse, the fuse shall be installed on the power supply side.

17. The strong and weak current terminals shall be arranged separately; When there are difficulties, there should be obvious signs and set up empty terminal separation or set up to strengthen the insulation of the partition.

18. The terminal shall have serial number, and the terminal block shall be easy to replace and connect; The height above the ground should be more than 350mm.

19. Shock absorption devices shall be added to electrical appliances with anti shock requirements, and anti loosening measures shall be taken for fastening bolts.

20. The fasteners shall be galvanized products, the bolt specifications shall be appropriate, and the electrical appliances shall be fixed firmly and stably.

21. The inclined opening should be cut at the end of guide rail for new blanking to prevent accidents during operation.

22. The trunking shall be flat without distortion, and the inner wall shall be smooth without burr.

23. The connection of trunking shall be continuous. There shall be no less than two fixed points for each section of trunking. There should be fixed points at the corner, branch and end, and they should be fixed close to the wall

24. The slot interface shall be straight and tight, and the slot cover shall be complete, flat and free of warping angle.

25. The screw or other fastener for fixing or connecting the trunking shall be connected with the inner surface of the trunking smoothly after fastening.

26. The laying of trunking shall be straight and neat, the horizontal or vertical allowable deviation shall be 2 ‰ of its length, and the total allowable deviation shall be 20 mm. When installed in parallel, the cover should be easy to open.

27. The outlet of trunking shall be in correct position, smooth and free of burr.

28. Matching of twist drill and tapping used in typesetting.

29. The linear distance between the terminal of circuit breaker and residual current circuit breaker and the trunking is 30mm.

30. When the copper joint of connecting elements is too long, the distance between elements and trunking should be appropriately relaxed.

31. The layout position of the switch or fuse holder used to connect the incoming line of the electric cabinet should consider the turning radius distance of the incoming line.

32. The linear distance between the terminal of contactor and thermal relay and the trunking is 30mm.

33. The linear distance between other current carrying elements and trunking is 30mm.

34. The linear distance between the control terminal and the trunking is 20 mm.

35. The linear distance between power terminal and trunking is 30mm.

36. The linear distance between the intermediate relay and other control elements and the trunking is 20 mm.

37. The installation of electrical components shall comply with the provisions of the product manual.

38. When fixing low-voltage electrical appliances, no additional stress shall be imposed on the interior of the appliances.

39. The installation of low-voltage circuit breaker shall comply with the provisions of product technical documents. If there is no clear provision, it should be installed vertically, and its inclination shall not be greater than 5 °。 40. Electrical components with electromagnetic moving parts or reset by gravity, such as various contactors and relays, shall be installed in strict accordance with the product manual, so as not to affect the reliability of their action.

41. According to their different structures, low-voltage electrical appliances can be fixed on walls, columns or other building components with supports, metal plates and insulating plates. The metal plate and insulating plate shall be flat. When the clamping rail is used to support the installation, the clamping rail shall be matched with the low-voltage apparatus, and shall be tightly fixed with the wall plate with the fixing clamp or fixing bolt. It is strictly forbidden to use the deformed or unqualified clamping rail.

42. Components and accessories shall be complete and intact.

43. The installation and fastening of electrical components shall be firm, and the fixing method shall be detachable.

44. Fasteners shall have galvanized or other reliable metal anti-corrosion layer.

45. The fastening of electrical components shall be equipped with anti loosing device. Generally, spring washer and flat washer shall be placed. The spring washer should be placed on one side of the nut and the flat washer on both sides of the fastening screw. If double nut locking or other locking devices are used, spring washer can be omitted.

46. When fastening the lapped teeth on the metal base plate, the length of the lapped teeth should not be less than 0.8 times of the bolt diameter after the bolt is tightened, so as to ensure the strength.

47. Fasteners for equipment installation shall be galvanized products, and standard parts shall be used.

48. When aluminum alloy parts are connected with non aluminum alloy parts, insulating gasket shall be used to prevent the influence of electrolytic corrosion.

49. When aluminum components are connected with steel parts, appropriate measures should be taken to avoid direct contact and electrolytic corrosion.

50. The incoming line at the power side should be connected to the incoming line end, that is, the fixed contact terminal; The load side outgoing line should be connected at the outgoing line end, i.e. moving contact terminal.

51. When installing component buttons on the panel, in order to improve efficiency and reduce errors, the code should be written directly behind the door with a pencil, and then the label should be pasted on the corresponding position, and finally the device should be installed and labeled.

52. The distance between buttons should be 50-80mm; The distance between button boxes should be 50-100 mm; When the installation is inclined, its inclination angle with the horizontal line should not be less than 30 ° 53. The operation of the button shall be flexible, reliable and free from jamming.

54. The buttons installed together shall be provided with numbers or different identification marks, and the "emergency" button shall be provided with obvious marks and protective cover.

55. The screw support of plexiglass shall be completed immediately after the installation of components, and the installation position must meet the requirements of the shortest linear distance from the live conductor.

56. The wiring of electrical appliances shall be made of copper or bolts and screws with electroplated metal antirust layer, which shall be tightened and equipped with anti loosening device.

57. When prefabricating the conductor of the component itself, the connecting terminal shall be used to connect with the conductor in the cabinet, and the docking method shall not be used as far as possible.

58. The enclosure of the equipment shall be able to prevent accidental live parts of the staff.