Page 324 - Electrician - TT (Volume 2)

ELECTRICIAN - CITS

Fig 4
The following are the common types of insulators in use.

• Pin type insulator
• Shackle insulator
• Suspension insulator
• Strain insulator

• Post insulator
• Stay insulator
• Disc insulator
Pin Insulators: Pin insulators are used for holding the line conductors on straight running of poles. Pin insulators
are three types. i.e single shed (Fig 1) double shed (Fig 2) and triple shed (Fig 3) The single -shed pin insulators
are used for low and medium voltage lines. The double and triple shed pin insulators are used for over 3000V.
These sheds are used to drip off the rain water.
The part section of a pin type insulator is in Fig 4a & 4b As the name suggest, the pin type insulator is secured to
the cross - arm on the pole. There is a groove on the top of the insulator for housing the conductor. The conductor
passes through this groove and is bound by the annealed wire of the same material as the conductor.

Fig 1 Fig 3

Fig 4
Fig 2

Shackle insulators : Shackle insulators are generally used for terminating on corner poles. These insulators are
used for medium voltage line only. (Fig 5a & 5b)

Fig 5a&b) Fig 6

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CITS : Power - Electrician & Wireman - Lesson 106-116 CITS : Power - Electrician & Wireman - Lesson 106-116