Question

Pin insulators are never used for voltages above _______.
1. 33 kV
2. 22 kV
3. 11 kV
4. 1.1 kV

Answer 1

Correct Answer - Option 1 : 33 kV

Pin Insulator:

• The pin insulator is used in power distribution for the voltage up to 33 kV
• Pin type insulators are not economical at operating voltages greater than 33 kV.
• It is placed on the cross arm of the supporting tower.
• The pin insulator has grooves on the upper end for keeping the conductor
• The conductor is tied to the insulator on the top groove on straight line positions and the side groove in angle positions by annealed binding wire of the same material as that of the conductor
• A lead thimble is cemented into the insulator body to receive the pin

Advantages:

• It has high mechanical strength
• The pin type insulator has good creepage distance
• It is used on the high voltage distribution line
• The construction of the pin type insulator is simple and requires less maintenance
• It can be used vertically as well as horizontally

Disadvantages

• It should be used with the spindle
• It is only used in the distribution line
• The voltage rating is limited, i.e., up to 33kV
• The pin of the insulator damaged the insulator thread