When the twist of the bus bar is 90 degrees, the length of the twisted part of the twist should not be less than the width of the bus bar
7.5.4 The bending degree of double-row or multi-row busbars should be consistent.
7.5.5 At the beginning of the busbar bend, the edge of the nearest busbar support should not be less than 50mm, and should not be greater than 0.25L (L is the distance between the adjacent support points of the busbar). The position is not less than 30mm. See Figure 5
7.6 L----the distance between two supporting points of the bus;
7.7 a---- busbar width;
7.8 b----Bus thickness.
7.9 7.5.6 The busbar bending is generally performed by cold bending. If heating is required, the temperature must not exceed the following requirements:
7.10 Row 250℃. Copper busbar 350℃. Except for the heating of the bent part of the busbar, other parts shall not be annealed.
7.11 7.5.7 The starting and ending positions of the three-phase bending of the branch busbar should also be consistent, and no obvious height phenomenon is allowed.
7.12 7.10 Drilling: The drilling of the busbar can be performed by hydraulic punching and punching die punching. Bench drills, vertical drills, portable electric drills are not allowed. Since the busbar connection uses bolts that are 1mm smaller than the hole diameter, the size deviation of the busbar drilling should not be It is greater than 0.5 mm. In order to ensure the accuracy of the hole, a drilling jig or scoring should be used to punch the sample. A flat drill bit should be used when drilling, and a slightly larger hole diameter should be used after drilling.
7.13 Deburring the drill bit at a 120-degree angle. All holes on the busbar (including secondary wire connection holes) must be drilled before surface treatment.
7.14 7.11 Contact surface processing
7.18.1 The busbars are not punched. The corners are processed, and the contact surface is relatively flat. After manual trimming, the tin plating can be directly bent. For 60×6 and above busbars, use a pit squat mold.
7.7.2 The processing effect of the contact surface is to eliminate the oxides, wrinkles and bumps on the surface of the busbar. Common methods are mold leveling and manual trimming. After punching, the contact surface of the corner cutting must be manually trimmed to remove the sharp corners and burrs of the contact surface, and the busbars of 60×6 and above should be flattened with a pit mold before bending tin plating.
7.7.3 The processing length of the contact surface should be 50mm more than the width of the overlapping part on each side
7.19 Copper busbar tin plating operation process: (outsourcing processing)
7.19.1 The copper busbar should be corroded in nitric acid solution for 10-15 seconds to wash off the oil on the surface of the copper busbar. After removing it, the residual acid on the surface of the copper busbar should be washed with water immediately
7.19.2 For tin plating of copper busbars, see "Code and Inspection Regulations of Copper Busbar Tin Plating Process"
7.20 Aluminum busbar chemical treatment process
7.20.1 The processed aluminum busbars are immersed in an aqueous solution containing about 30% sodium hydroxide. After removing the oil stains and oxide films on the surface of the aluminum busbars, they are taken out.
7.20.2 Immerse in the flowing water and use a brush to remove the residual alkali from the surface of the aluminum busbar. After cleaning, take out, immediately wipe off the surface moisture with a clean towel, and then dry or dry before installing.
7.10 The treatment of the overlapping surfaces of busbars and busbars, busbars and branched busbars, busbars and electrical terminals shall meet the following requirements:
a. Copper and copper: tinned connection;
b. Aluminum and aluminum: direct connection;
c. Copper and aluminum: copper conductors are tinned, when the user has special requirements (outdoor power distribution or indoor relative humidity connection
When it is close to 100%, copper-aluminum transition plate should be used, and the copper end is tinned;
d. Close the busbar bolts to fix the lap surface, and tin should be tinned if possible