Important Indian Electricity Rules (IE-1956 & IE-1957)

Important Indian Electricity Rules (IE-1956 & IE-1957)

As an Electrical Engineer or supervisor, it is very important to follow the Electricity rules and the safety precautions while carrying out the electrical installations, some of the Important Indian Electricity Rules are mentioned below for your reference and knowledge.

India Electricity Rule No.-54

A supplier shall not permit the voltage at the point of commencement of supply to vary from the declared voltage.

a) In case of low & medium voltage, the variation not more than by 6%.

b) In case of High voltage by 6% in the higher side and 9% in lower side.

c) In case of Extra high voltage by 10% in the higher side and 12.5% in lower side.

India Electricity Rule No.-55

Declared frequency of A.C supply to consumer to vary from the declared frequency by more than 3%.
India Electricity Rule No.-56

Stipulates that the supplier may affix one or more seals to meters and cutouts and no person other than the supplier shall break any such seal.
India Electricity Rule No.-57

Stipulates the provision to ensure correctness of meters, maximum demand indicators and other apparatus on consumers premises.
India Electricity Rule No.-58

It states the point of commencement of supply” The point of commencement of supply of an energy to a consumer shall be deemed to be the point at the incoming terminal of cutouts installed by the consumer under rule no.50.
India Electricity Rule No.-59

Provides precautions to be taken against failure of supply and notice of failures to be given.
India Electricity Rule No.-76

Stipulates maximum stresses”factor of safety”

a) for metal supports= 1.5

b) for mechanically processed concrete support= 2.0

c) for hand moulded concrete support= 2.5

d) for wood support= 3.0

e) minimum factor of safety for stay wires, ground wires or bearer wires shall be= 2.5

f) minimum factor of safety for conductor= 2.0

Safety Factor = (Ultimate Stress/ Actual Stress)
India Electricity Rule No.-77

Minimum ground clearances as per IE- 1956
Voltage in kV To ground in Metre

132 6.10

220 7.0

400 8.84

800 12.40

Overhead lines along the street (parallel to the street) & across the street/ road

Voltage LevelGround clearances in meter(along the street)Ground clearances in meter(across the street)
Low and Medium Voltage5.55.8
High Voltage5.86.1
Extra High Voltage5.8 + add 0.3 meter for every additional 33 kV6.1 + add 0.3 meter for every additional 33 kV

Overhead lines without across or along the street/ road

Voltage Level in kVGround clearances in meter
Low/medium/HT Line up to 11 kV, if bare conductor4.6
Low/medium/HT Line up to 11 kV, if insulated conductor4.0
Above 11 kV Line5.2
Above 33 kV Line5.8 + add 0.3 meter for every additional 33 kV

India Electricity Rule No.-78

Clearances between Trolley/Tram and Conductors

Voltage level in kVClearances in meter
Low and Medium voltage1.2
High Voltage up to 11 kV1.8
High Voltage above 11 kV2.5
Extra High Voltage line3.0

India Electricity Rule No.-79

Clearances for roof, open balcony, Verandah roof and lean to roof

Line passes throughClearances in meter
Line passes over building vertical clearances2.5
Line passes adjustments of buildings horizontal clearances1.2
For pitched roof
Line passes over building vertical clearances2.5
Line passes adjustments of buildings horizontal clearances1.2

India Electricity Rule No.-85

Stipulates maximum interval between supports, all conductor shall be attached to supports at intervals not exceeding the safe limit based on ultimate tensile strength of the conductor and the factor of safety prescribed in Rule No.-76.
India Electricity Rule No.-87

Minimum clearances between line crossing each other (IE 1957)

System Voltage in kV11-66 kV132kV220kV400kV800kV
Low and Medium2.443.054.585.497.94
11-662.443.054.585.497.94
1323.053.054.585.497.94
2204.584.584.585.497.94
4005.495.495.495.497.94
8007.947.947.947.94

Minimum Height above railway as per IE-195

Voltage levelBroad meter & narrow gauge
Above 66 kV up to 132 kV14.60
Above 132 kV up to 220 kV15.40
Above 220 kV up to 400 kV17.90
Above 400 kV up to 500 kV19.30
Above 500 kV up to 800 kV23.40

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