Instroduction for insulators:
According to materials insulators can be divided into porcelain insulators and polymer insulators, which support and insulate the conductors or wires, playing an important role in electrical systems.
Regardless of how conductors are supported structurally, they are always are electrically insulated from their supports and from other components on the distribution line by insulators. Porcelain, glass and silicone rubber materials can provide high mechanical and electrical performance.
Insulators also come in a variety of sizes. The size used depends on operating conditions and the voltage of the circuit. For example, the large insulators are supporting and insulating the lines of above 69kv subtransmission circuit. The smaller insulators are supporting and insulating the lines of below 33kv distribution circuit.
Disc insulators:
Insulators are made in number of different shapes for variety of uses in transimssion line or distribution line. Disc insulators are designed to be connected together in strings. Disc insulators can be added to or removed from a string to meet any voltage requirement. In distribution systems, disc insulators are typically mounted horizontally to connect conductor or vertical to suspend conductor. Disc insulators can be used from 11kv to 1100kV.
Post insulators:
Post insulators are normal used insulators that are cylindrical in shape and that are mounted flush with a support structure. Post insulators may be mounted vertically on the tops of poles or crossarms, or horizontally on the side of a pole.
Pin insulators:
Pin insulators can be made in a variety of shapes. In general, the pin insulator is assembled with a spindle and mounted on crossarm of pole.
Spool insulators:
Spool insulator is shaped like a spool or reel, so it also called reel insulator. Spool insulators can be clamped individually to the side of a pole, or several spools can be mounted in a rack on the side of a pole. Spool insulators are primary used to insulate secondary conductors and neutral wires.