Question

Under the Indian Electricity Rules, the maximum permissible frequency fluctuation is:

1.  ± 10 % of the declared frequency
2. ± 1 % of the declared frequency
3. ± 5 % of the declared frequency
4. ± 3 % of the declared frequency

Answer 1

Correct Answer - Option 4 : ± 3 % of the declared frequency

• As per the Indian Electricity Rules 1956 (amended up to 25th Nov 2000), the permissible range for grid frequency is ± 3 % of nominal i.e. 48.5 Hz to 51.5 Hz.
• The nominal frequency of operation in the Indian grid is 50.0 Hz and the permissible frequency band specified by Indian Electricity Grid Code (IEGC) is 49.5 Hz to 50.2 Hz with reference to 3rd May 2010.

 

 

I.E. rules are given below

IE Rule 50: Supply and use of energy.

IE Rule 54: Declared voltage of supply to the consumer.

IE Rule 55: Declared frequency of supply to the consumer.

IE Rule 30: Service Lines and apparatus on consumer’s premises.

IE Rule 39: Cables protected by bituminous materials.

IE Rule 51: Provisions applicable to medium, high or extra-high voltage installations.

IE Rule 73: Supply to X-ray and high-frequency installation.