Electrical Revolution: Standard Alternating Voltage in India

The standard voltage ( in India ) for low and medium line distribution was 230 V for single phase and 230 / 400 V for three phase system but due to economic advantage IEC recommended 240 V for single phase and 240 / 415 V for three phase system voltage with ± 6% voltage variation.

The IEC decided ± 10% voltage variation allowed for 240 V for single phase and 240 / 415 V for three phase system voltage in the year 2009.
The 110 kV is not standard transmission voltage but it is included due to sake of equipment which are already used for 110 kV.
The standard DC distribution voltage is 220 / 440 V.

Standard Alternating voltage Line to Line

240 V ( Line to Neutral )
415 V
3.3 kV
11 kV
22 kV
33 kV
66 kV
110 kV
132 kV
220 kV
400 kV

Voltage Variations Limits

10% for low voltage
6% for higher side and 9% on lower side in the high voltage transmission
12.5% for extra high voltage transmission

The system voltage with lowest voltage and highest voltage is summarized as below.

System voltage	Lowest voltage	Highest voltage
240 V	216 V	264 V
415 V	374 V	457 V
3.3 kV	3.0 kV	3.6 kV
6.6 kV	6.0 kV	7.2 kV
11 kV	10 kV	12 kV
22 kV	20 kV	24 kV
33 kV	30 kV	36 kV
66 kV	60 kV	72.5 kV
132 kV	120 kV	145 kV
220 kV	200 kV	245 kV
440 kV	380 kV	420 kV