The 126kV -252kV insulated switch arm is an important component in high-voltage electrical equipment such as gas insulated metal enclosed switchgear (GIS), mainly used to transmit mechanical force and achieve insulation function. Here are some introductions about it:
structural characteristics
Material: High strength insulation materials such as epoxy resin glass fiber composite materials are usually used, which have good insulation performance and mechanical strength. Some insulated toggle arms will also be made of metal materials such as aluminum alloy, and used in conjunction with insulated components, such as the 7A04-T6 aluminum alloy toggle arm, which is lightweight and easy to install.
Connection method: The insulated crank arm is usually connected to components such as insulated pull rods and transmission shafts through pin shafts, splines, and other methods. In a 252kV sealed vacuum circuit breaker, the bottom end of the insulation rod is connected to the inner crank arm through a rod joint, and the inner crank arm is then connected to the outer crank arm. The inner and outer crank arms are connected to the transmission housing inside the mechanism box through a transmission shaft, and the outer crank arm is also connected to the circuit breaker mechanism through a pin shaft and main rod.
working principle
In GIS isolation switches, the movable contacts, clamps, and connecting arms are connected together to form the movable part inside the isolation switch. When the mechanism gives a closing operation command, the connecting mechanism of the mechanism drives the shaft seal and insulation rod to rotate, thereby driving the crank arm to rotate. The crank arm pushes the fork and the moving contact to move towards the static conductor, making the moving contact fully contact the static contact and completing the closing operation. When the switch is opened, the mechanism drives the shaft seal and insulation rod to rotate in the opposite direction, and the connecting arm also rotates in the opposite direction, pulling the fork and moving contact back to achieve the switch.
Performance Requirements
Insulation performance: It needs to meet the insulation requirements under the voltage level of 126kV -252kV, and be able to withstand corresponding power frequency withstand voltage, lightning impulse withstand voltage and other tests to ensure that insulation breakdown, flashover and other phenomena do not occur in high voltage environments.
Mechanical performance: It should have sufficient mechanical strength and stiffness to withstand the mechanical stresses generated during the operation of switchgear, such as tension, compression, bending, etc. At the same time, it should also have good fatigue resistance and be able to maintain stable mechanical performance during long-term and frequent operation.
effect
Transmitting mechanical force: transmitting the mechanical motion of the operating mechanism to the moving contacts of the switchgear, achieving the opening and closing operation of the switch, and ensuring the normal operation of the switchgear.
Insulation isolation: As an insulating component, the insulation crank arm can ensure electrical insulation between components with different potentials while transmitting mechanical force, preventing electrical short circuits and other faults, and ensuring the safety of equipment and personnel.

Note: Customization with drawings is available