The contact arm is divided into two parts:
1. Male contact i.e moving contact
2. Female contact i.e Fixed contact
1. The moving contact is opened by an operating mechanism.
2. The contact is supported on the solid core insulators.
3. Operating blade is supported on the operating rod insulators.
4. All the insulators are fixed on the base.
5. Earthing switches are also fixed on the isolators and linked with the isolators.
6. Isolators, earth switches, and circuit breakers are interlocked to avoid maloperation to protect the equipment and provide safety to the operating staff.
7. The operation of the isolator may be manual and or with an electrical/pneumatic mechanism.
8. These isolators are used in outdoor applications including isolation of a circuit breaker, transformer banks, and surge arresters and line sectioning.
Horizontal Break (Center Rotating Double Break) type Isolator
1. Fixed female contacts of metal are supported on the stack of insulators.
2. Male contact rod is connected to the central insulating support which can be moved to have a horizontal moment of the male contact for operating or closing into the female contacts.
3. The moment of the rod and its support may be done by manually or electrically or pneumatically by operators.
4. The operating mechanism disengages or engages the rod in the female contacts for closing or opening operation of the isolator.
5. The male contact's moment is horizontal and hence this type of isolator is named as horizontal break isolator.
6. The assembly is supported on the galvanised steel channel or steel frame.
7.The moving male contact can be moved through 90 degree.
8. This type is used indoor or outdoor equipment of capacity above 245Kv.