Question

Which among these is a configuration of an isolator?

1. Vertical break type
2. Horizontal type
3. Horizontal break with two post insulator
4. Horizontal break centre post rotating double break
5. Pantograph type

1. Only b and c
2. a, b,  and d
3. a, b, c, d and e
4. a, b, d, e

Answer 1

Correct Answer - Option 3 : a, b, c, d and e

Isolator: An isolator is disconnecting switch being operated under the condition of on load or negligible current. It is used in the power system for disconnecting the circuit from the circuit at the time of repair and maintenance work.

The types of isolators are:

• Vertical break type, single, double or triple pole isolator consisting mainly of fixed soiled core type insulator support with rigid contacts and moving copper blade supported by operating rod insulator.
• Horizontal type, used at the voltage upto 220 kV.
• Horizontal break with two post insulator, consisting of mounted on a bearing and also rotatable about its vertical axis through 30°.
• Horizontal break centre post rotating double break isolator consisting of three insulator stacks per pole having two insulator stacks fixed on sides and centre insulator stack rotating.
• Pantograph type, is an extra high voltage column isolator consisting of a two part pantograph on the top, revolving drive insulator, solid core type porcelain insulator acting as the main supporting unit, the operating cubicle provided with all necessary auxillary contacts & other contacts for supervision & control and a vertically erected steel the support anchored to /the concrete plinth.