Minimum Electrical Clearance

 

Minimum Electrical Clearance As Per BS:162.

INDOOR
Voltage in KVPhase to earth in mmPhase to phase in mm
0.41515.819.05
0.60019.0519.05
3.350.850.8
6.663.588.9
1176.2127.0
15101.6165.1
22139.7241.3
33222.25355.6

Minimum Electrical Clearance As Per BS:162.

OUTDOOR
Voltage in KVPhase to earth in mmPhase to phase in mm
6.6139.7177.8
11177.8228.6
22279.4330.2
33381431.8
66685.8787.4
110863.6990.6
1321066.81219.2
22017782057.4

 Minimum Working Clearance:

OUTDOOR SWITCHYARD
Voltage in KVTo ground in mmBetween section(mm)
1127502500
3337002800
6640003000
13246003500
22055004500

 Minimum Ground Clearance As Per IE-1956(Rule 77)

Voltage in KVTo ground in mm
1326.10
2207.00
4008.84
80012.40
  

Minimum Clearance between Lines Crossing Each Other (IE-1957)

System Voltage132KV220KV400KV800KV
Low & Medium3.054.585.497.94
11-66KV3.054.585.497.94
132KV3.054.585.497.94
220KV4.584.585.497.94
400KV5.495.495.497.94
800KV7.947.947.947.94

Minimum Height above Railway As Per IE-1957

VoltageBroad Meter & Narrow Gauges
Above 66KV up to 132KV14.60 Meter
Above 132KV up to 220KV15.40 Meter
Above 220KV up to 400KV17.90 Meter
Above 400KV up to 500KV19.30 Meter
Above 500KV up to 800KV23.40 Meter

Various Air clearances to be provided as per IE rule 64

Voltage KV33KV66KV110KV220KV400KV
BIL (Kvp)17032555010501425
P-E (cm)3063115240350
P-P(cm)4075135210410
P-G (Meter)3.74.04.65.58.0
Section Clearance(Mt)2.83.03.54.36.5

Clearances from Buildings of HT and EHT voltage lines IE Rule 80

Vertical Distance
High voltage lines up to 33KV3.7 Meter
Extra High Voltage3.7 Meter + Add 0.3 meter for every additional 33KV
Horizontal clearance between the conductor and Building
High Voltage Up to 11 KV1.2 Meter
11KV To 33KV2.0 Meter
Extra High Voltage2.0 Meter + Add 0.3 meter for every additional 33KV

Clearance above ground of the lowest conductor As per IE Rule 77

Over head Line Across Street
Low and Medium Voltage5.8 Meter
High Voltage6.1 Meter
Over head Line Along  Street (Parallel To Street)
Low and Medium Voltage5.5 Meter
High Voltage5.8  Meter
Over head Line Without Across or Along  Street
Low/Medium /HT line up to 11KV If Bare Conductor4.6 Meter
Low/Medium /HT line up to 11KV If Insulated Conductor4.0 Meter
Above 11  KV Line5.2 Meter
Above 33KV Line5.8 Meter + Add 0.3 meter for every additional 33KV

Clearance between conductors and Trolley / Tram wires (IE Rule 78)

Low and Medium Voltage1.2 Meter
High Voltage Line Up to 11KV1.8 Meter
High Voltage Line Above to 11KV2.5 Meter
Extra High Voltage Line3.0 Meter
  

 Clearances from Buildings of low & medium voltage lines(IE Rule 79 )

For  Flat roof, Open Balcony, Verandah Roof and lean to Roof
Line Passes Over Building Vertical Clearance2.5 Meter
Line Passes Adjustment of Building Horizontal Clearance1.2 Meter
For pitched Roof
Line Passes Over Building Vertical Clearance2.5 Meter
Line Passes Adjustment of Building Horizontal Clearance1.2 Meter