About 11/22/33kV Isolators
They are mechanical switches which isolate a part of circuit from system as when required. These isolators separate a part of the system from rest for safe maintenance works. These have three stacks of post insulators . The central post insulator carries a tubular or flat male contact which can be rotated horizontally with rotation of central post insulator. This rod type contact is also called moving contact. The female type contacts are fixed on the top of the other post insulators which are fitted at both sides of the central post insulator.
The female contacts are generally in the form of spring loaded figure contacts .Both fixed and moving contacts are of EC grade copper. The rotational movement of male contact causes to come itself into female contacts and isolators becomes closed. The rotation of male contact in opposite direction make to it out from female contacts and isolators becomes open. Rotation of the central post insulator is done by a driving lever mechanism at the base of the post insulator and it is connected via operating handle.