Question

Suspension type insulators are used for voltages beyond _______.

• A. 132 kV
• B. 33 kV
• C. 400 kV
• D. 11 kV

Hint:

Use suspension insulators when voltage>33 kV. Pin insulators only for LV/MV lines.

Answer 1

The Correct Option is B

Step 1: What are Suspension Insulators?
These are disc-type insulators connected in series to support high voltage transmission lines. The number of discs depends on the voltage level.
Step 2: When Are They Used?
For voltages above 33 kV, pin-type insulators become bulky and uneconomical. Hence, suspension-type insulators are preferred as they:
- Offer modular insulation.
- Withstand high mechanical loads.
- Are easy to maintain.
Step 3: Industry Practice
For 11 kV and 22 kV systems, pin insulators are common. At 33 kV and beyond, suspension insulators become practical and are standard practice in HV systems.
Conclusion:
Suspension insulators are widely used from 33 kV upwards.