8/11/2019 28.Basics of Substations

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Standard clearances are:

Voltage level Phase to Phase Phase to ground

33kV 0.73 M 0.6 M

132kV 3.0 M 3.1 M

220kV 4.5 M 4.0 M

400kV 7.0 M 6.5 M

Minimum clearances for bare conductors or live parts of any

apparatus in outdoor substations (Rule 64(2) (a) ii of IE rules1956)

VOLTAGE CLASSGROUND

CLEARANCE (M)

SECTIONAL

CLEARANCE

(M)

Not Exceeding 11kV 2.75 2.60

Not Exceeding 33kV 3.70 2.80

Not Exceeding 132kV 4.60 3.50

Not Exceeding 220kV 5.50 4.30

Not Exceeding 400kV 8.0 7.0