(A) Disc insulator
(B) Suspension insulator and Pin insulator
(C) Pin insulator
(D) Suspension insulator
Answer: (D) Suspension insulator
Explanation:
Pin insulators are commonly used in power networks up to 33 kV system
Post insulator is suitable for lower voltage and also for high voltage
Each suspension disc is designed for normal voltage rating 11 kV (Higher voltage rating 15 kV), so by using different numbers of discs, a suspension string can be made suitable for any voltage level; Hence suspension insulator is suitable for high voltage transmission lines
The shackle insulator is usually used in a low voltage distribution network
In a suspension insulator number of insulators is connected in series to form a string and the line conductor is carried by the bottom-most insulator.
Each insulator of a suspension string is called a disc insulator because of its disc-like shape.
Each suspension disc is designed for a normal voltage rating of 11 kV, so by using different numbers of discs, a suspension string can be made suitable for any voltage level.
INSULATORS | USED FOR |
Suspension type | interconnected porcelain discs capable of transmitting higher voltages |
Pin type | Used on straight running transmission lines to transmit voltages upto 33 kV. |
Strain type | horizontally suspended suspension insulators that can handle large mechanical stresses such as a river crossing. |
Post type | used in areas with heavy pollution and risk of vandalism exhibit high resistance to puncture |
1. Under over excitation synchronous phase modifier works as
2. The neutral of the power system may be connected to earth
3. The time to open the circuit breaker contact is called as
4. A 100 Ah capacity battery should deliver a current of 10 A for approximately _____ hrs.
5. For 400KV line, The Spacing Between phase conductor is around
6. Shunt capacitors in a sub-station
7. An alternator is said to be over excited when it is operating at
8. In case of transformer Buchholz relay is used to protect from
9. Series capacitors are used to
10. Disadvantage of low power factor is
11. The colour of neutral three core flexible cable is
12. The location of ground faults in underground cables can be found by
13. Fault location in an HV cable is done by
15. Which of the following is not a valid advantage of bundle conductor?
16. Star-star power transformer is protected by current transformer having
17. The surge resistance of cables is
18. Skin effect is only noticeable at _______ frequencies.
19. When transmission voltage is increased, the line losses are