Minimum Electrical Clearance
Minimum Electrical Clearance As Per BS:162.
INDOOR | ||
Voltage in KV | Phase to earth in mm | Phase to phase in mm |
0.415 | 15.8 | 19.05 |
0.600 | 19.05 | 19.05 |
3.3 | 50.8 | 50.8 |
6.6 | 63.5 | 88.9 |
11 | 76.2 | 127.0 |
15 | 101.6 | 165.1 |
22 | 139.7 | 241.3 |
33 | 222.25 | 355.6 |
Minimum Electrical Clearance As Per BS:162.
OUTDOOR | ||
Voltage in KV | Phase to earth in mm | Phase to phase in mm |
6.6 | 139.7 | 177.8 |
11 | 177.8 | 228.6 |
22 | 279.4 | 330.2 |
33 | 381 | 431.8 |
66 | 685.8 | 787.4 |
110 | 863.6 | 990.6 |
132 | 1066.8 | 1219.2 |
220 | 1778 | 2057.4 |
Minimum Working Clearance:
OUTDOOR SWITCHYARD | ||
Voltage in KV | To ground in mm | Between section(mm) |
11 | 2750 | 2500 |
33 | 3700 | 2800 |
66 | 4000 | 3000 |
132 | 4600 | 3500 |
220 | 5500 | 4500 |
Minimum Ground Clearance As Per IE-1956(Rule 77)
Voltage in KV | To ground in mm |
132 | 6.10 |
220 | 7.00 |
400 | 8.84 |
800 | 12.40 |
Minimum Clearance between Lines Crossing Each Other (IE-1957)
System Voltage | 132KV | 220KV | 400KV | 800KV |
Low & Medium | 3.05 | 4.58 | 5.49 | 7.94 |
11-66KV | 3.05 | 4.58 | 5.49 | 7.94 |
132KV | 3.05 | 4.58 | 5.49 | 7.94 |
220KV | 4.58 | 4.58 | 5.49 | 7.94 |
400KV | 5.49 | 5.49 | 5.49 | 7.94 |
800KV | 7.94 | 7.94 | 7.94 | 7.94 |
Minimum Height above Railway As Per IE-1957
Voltage | Broad Meter & Narrow Gauges |
Above 66KV up to 132KV | 14.60 Meter |
Above 132KV up to 220KV | 15.40 Meter |
Above 220KV up to 400KV | 17.90 Meter |
Above 400KV up to 500KV | 19.30 Meter |
Above 500KV up to 800KV | 23.40 Meter |
Various Air clearances to be provided as per IE rule 64
Voltage KV | 33KV | 66KV | 110KV | 220KV | 400KV |
BIL (Kvp) | 170 | 325 | 550 | 1050 | 1425 |
P-E (cm) | 30 | 63 | 115 | 240 | 350 |
P-P(cm) | 40 | 75 | 135 | 210 | 410 |
P-G (Meter) | 3.7 | 4.0 | 4.6 | 5.5 | 8.0 |
Section Clearance(Mt) | 2.8 | 3.0 | 3.5 | 4.3 | 6.5 |
Clearances from Buildings of HT and EHT voltage lines IE Rule 80
Vertical Distance | |
High voltage lines up to 33KV | 3.7 Meter |
Extra High Voltage | 3.7 Meter + Add 0.3 meter for every additional 33KV |
Horizontal clearance between the conductor and Building | |
High Voltage Up to 11 KV | 1.2 Meter |
11KV To 33KV | 2.0 Meter |
Extra High Voltage | 2.0 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 Voltage | 5.8 Meter |
High Voltage | 6.1 Meter |
Over head Line Along Street (Parallel To Street) | |
Low and Medium Voltage | 5.5 Meter |
High Voltage | 5.8 Meter |
Over head Line Without Across or Along Street | |
Low/Medium /HT line up to 11KV If Bare Conductor | 4.6 Meter |
Low/Medium /HT line up to 11KV If Insulated Conductor | 4.0 Meter |
Above 11 KV Line | 5.2 Meter |
Above 33KV Line | 5.8 Meter + Add 0.3 meter for every additional 33KV |
Clearance between conductors and Trolley / Tram wires (IE Rule 78)
Low and Medium Voltage | 1.2 Meter |
High Voltage Line Up to 11KV | 1.8 Meter |
High Voltage Line Above to 11KV | 2.5 Meter |
Extra High Voltage Line | 3.0 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 Clearance | 2.5 Meter |
Line Passes Adjustment of Building Horizontal Clearance | 1.2 Meter |
For pitched Roof | |
Line Passes Over Building Vertical Clearance | 2.5 Meter |
Line Passes Adjustment of Building Horizontal Clearance | 1.2 Meter |