In cable distribution boxes, a bar switch is actually a type of horizontally arranged isolating switch. Like a traffic officer in a circuit, it controls the synchronous opening and closing of multiple sets of contacts via mechanical linkages. This design uses silver-plated copper busbars as the conductive body, typically 60-100mm wide, and can withstand rated currents from 630A to 1250A. Operation is simple: just rotate the insulated handle on the outside of the box to control the circuit's on/off state.
Why are bar switches needed?
Space optimization: The flat design saves 30% of installation space compared to traditional switches.
Synchronous control: A single operation can simultaneously cut off current in 3-4 circuits.
Visible break point: A clear disconnection gap is formed when the contacts separate.
Easy maintenance: Contact inspection can be performed without disassembling the box.
Key points for use:
When operating a bar switch, ensure the handle rotation angle is correct; otherwise, an arc may occur. In humid environments, check the insulation for moisture beforehand. In low winter temperatures, check for solidified lubricating grease. It is recommended to check the contact erosion every six months, and replace the switch when the silver plating wears more than 50%. Non-professionals should never operate the equipment while it is powered on, and the grounding wire of the enclosure must be reliably connected.