Types of Insulator

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 Insulator is a substance through which electron doesn't flow. The overhead line conductors should be supported on the poles or tower in such a way that current from the conductors do not flow to earth through support.

The types of Insulator are following:

1.) Pin type Insulator:

The pin type Insulator is secured to the cross-arm on the pole. Pin type Insulator operate satisfactory required for transmission and distribution of Electrical voltage upto 33 kV. The value of safety factor for pin type Insulator is about 10.

Fig. Pin type Insulator

2.) Suspension type Insulators:-

The suspension type Insulator consists of number of procelain discs connected in series by metal link in the form of a string. A suspension Insulator is designed to operate at 11 kV. The no. disc in series would depend upon the working voltage.

Fig. Suspension type Insulator

3.) Shackle Insulator:- 

Shackle type Insulator are used I  tension cable. These Insulator can be operated either horizontally and vertically. They can be directly fixed to the pole with a bolt or to the cross arm. The conductor in the groove is fixed with a soft winding wire. In shake type Insulator, distribution of voltage upto 11Kv.

Fig. Shackle type Insulator


4.) Strain type Insulator:-

Strain type Insulator is mechanically strong. It is used when direction of transmission line changes across river crossing and at the dead end of transmission line. For low voltage, lines(<11 kV), shackle Insulators are used as strain Insulators. For hind voltages transmission lines, strain conductors consists of an assembly of suspension Insulators.

Fig. Strain type Insulator





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