Earthing switches of series EK6 have three pairs of earthing blades which are located on the operating shaft and are freely movable. The pairs of earthing blades are electrically connected to each other by a shortcircuiting bridge and to earth potential at the bearing brackets by two stranded copper conductors. Driver levers and toggle springs located between the bearing brackets are used to transmit the force during the switching process. Fixing the active part on a torsionally rigid switchgear panel wall or cross beam provides it with the necessary stability.
The earthing contacts designed to suit the relevant switch type are to be bolted to the conductor bars supported on suitable insulating parts, e.g. pintype insulators, on the opposite side and parallel to each other, and the position adjusted until it conforms to that show in the dimensional drawings. The earthing switch has a snap action closing mechanism which functions independently of the rotation of the drive shaft. The switching speed and torque achieved in this process are independent of the actions of the operating mechanism.
In the opening process, in contrast, the toggle springs have no effect on the speed of contact separation. A ring lever or suitable manual or motorized operating mechanism with the necessary torque for the type of switch and an operating angle 90° can be fitted for operation of the switch.
Note: Always open earthing switches by turning until the stop is reached.