**Continued from part 1** – Electrical Safety Standards for LV/MV/HV (Part-1)

## Content

**Standard: Northern Ireland Electricity (NIE), 6/025 ENA**

- Clearances of Electrical Line to Ground and Roads
- Clearances of Electrical Line to Other Objects
- Clearances of Electrical Line to Trees and Hedges
- Clearances of Electrical Line to Street Lighting
- Clearances of Electrical Line to Waterways
- Clearances to Railways
- Clearances of Electrical Line to Fuel Tanks
- Clearances of Electrical Lines to other Electrical Lines
- Vertical Passing Clearance (sites where vehicles will pass below the lines)
- Horizontal Clearance (sites where there will be no work or passage of plant under lines)
- Distance between Conductors of Same/Different Circuit (On Same Support)
- Vertical Distance between Conductors of different Circuit (On Different Support)
- Distance between Conductors (Taken down from Pole to other Support, on Transformer)
- Horizontal Distance of Telecommunication Line & Overhead Line
- Passage Way for Metal-Clad Switchgear
- Safe approach distance for Person from Exposed Live Parts

## Standard: Northern Ireland Electricity (NIE), 6/025 ENA

### Clearances of Electrical Line to Ground and Roads

Description of Clearance |
0.4 KV |
11 KV |
33KV |
110KV |
220 KV |
400KV |

Line conductor to any point not over road | 5.2 Meter | 6.1 Meter | 6.4 Meter | 6.4 Meter | 7.0 Meter | 7.0 Meter |

Line conductor to road surface | 5.8 Meter | 6.1 Meter | 6.4 Meter | 6.4 Meter | 7.4 Meter | 8.1 Meter |

Line conductor to road surface of high load routes | 6.9 Meter | 6.9 Meter | 6.9 Meter | 7.2 Meter | 8.5 Meter | 9.2 Meter |

Bare live metalwork ( transformer terminals, jumper connections, etc) | 4.6 Meter | 4.6 Meter | 4.6 Meter | – | – | – |

### Clearances of Electrical Line to Other Objects

Description of Clearance |
<11 KV |
33 KV |
110KV |
220KV |
400 KV |

Line conductor or bare live metalwork to any object that is normally accessible (including permanently mounted ladders and access platforms) or to any surface of a building | 3.0 Meter | 3.0 Meter | 3.4 Meter | 4.6 Meter | 5.3 Meter |

Line conductor or bare live metalwork to any object to which access is not required AND on which a person cannot stand or lean a ladder | 0.8 Meter | 0.8 Meter | 1.2 Meter | 2.4 Meter | 3.1 Meter |

Line conductors to irrigates, slurry guns and high-pressure hoses | 30 Meter | 30 Meter | 30 Meter | 30 Meter | 30 Meter |

Line conductors to playing fields | 8.5 Meter | 8.5 Meter | 8.5 Meter | 8.5 Meter | 8.5 Meter |

Line conductors to Caravan Sites | 9.0 Meter | 9.0 Meter | 9.0 Meter | 9.0 Meter | 9.0 Meter |

Horizontal clearances to wells | 15.0 Meter | 15.0 Meter | 15.0 Meter | 15.0 Meter | 15.0 Meter |

### Clearances of Electrical Line to Trees and Hedges

Description of Clearance |
<11 KV |
33 KV |
110KV |
220KV |
400 KV |

Line conductor or bare live metalwork to trees or hedges unable to support a ladder or being climbed. | 0.8 Meter | 0.8 Meter | 1.2 Meter | 2.4 Meter | 3.1 Meter |

Line conductor or bare live metalwork to trees or hedges capable of supporting a ladder or being climbed. | 3.0 Meter | 3.0 Meter | 3.4 Meter | 4.6 Meter | 5.3 Meter |

Line conductor or bare live metalwork to trees falling towards the overhead line with the line conductors hanging vertically. | 0.8 Meter | 0.8 Meter | 1.2 Meter | 2.4 Meter | 3.1 Meter |

Line conductors to trees in Orchards | 3.0 Meter | 3.0 Meter | 3.4 Meter | 4.6 Meter | 5.3 Meter |

### Clearances of Electrical Line to Street Lighting

Description of Clearance |
0.4 KV |
11 KV |
33KV |
110KV |
220 KV |
400KV |

Line conductor to Lantern on same pole | 1.0 Meter | – | – | – | – | – |

Bare line conductor to lantern or column below. | 1.5 Meter | – | – | – | – | – |

Insulated line conductor to column | 0.3 Meter | – | – | – | – | – |

Insulated line conductor to lantern | 1.0 Meter | – | – | – | – | – |

Column to nearest LV pole | 1.5 Meter | – | – | – | – | – |

Line conductor to street lighting column with | ||||||

(1) Column in normal upright position. |
– | 1.7 Meter | 1.7 Meter | 2.3 Meter | 3.3 Meter | 4.0 Meter |

(2) Column falling towards line with line conductor hanging vertically only |
– | 1.7 Meter | 1.7 Meter | 2.3 Meter | 3.3 Meter | 4.0 Meter |

(3) Column falling towards line |
– | 0.4 Meter | 0.4 Meter | 0.8 Meter | 1.4 Meter | 1.9 Meter |

### Clearances of Electrical Line to Waterways

Description of Clearance |
0.4 KV |
11 KV |
33KV |
110KV |
220 KV |
400KV |

Navigable Waters: Lower bank to conductor or earth wire |
10.5 Meter | 10.5 Meter | 10.5 Meter | 10.5 Meter | 10.5 Meter | 10.5 Meter |

Minor Watercourses : Lower bank to conductor or earth wire |
7.6 Meter | 7.6 Meter | 7.6 Meter | 7.6 Meter | 7.6 Meter | 7.6 Meter |

### Clearances to Railways

Description of Clearance |
0.4 KV |
11 KV |
33KV |
110KV |
220 KV |
400KV |

Line conductor to ground level | 6.1 Meter | 6.1 Meter | 6.1 Meter | 6.7 Meter | 7.0 Meter | 7.6 Meter |

Line conductor to ground level on or across vehicle parks | 7.6 Meter | 8.5 Meter | 8.5 Meter | 9.1 Meter | 9.4 Meter | 10.1 Meter |

Line conductor to ground level at roads and yards, where road mobile cranes are likely to be employed | 10.7 Meter | 10.7 Meter | 10.7 Meter | 11.2 Meter | 11.5 Meter | 12.2 Meter |

Line conductor to Rail level | 7.3 Meter | 7.3 Meter | 7.3 Meter | 8.0 Meter | 8.2 Meter | 8.8 Meter |

Line conductor to the level of buildings, gantries or other structures (including those carrying traction wires) on which a man may be | 3.0 Meter | 3.0 Meter | 3.0 Meter | 3.7 Meter | 4.6 Meter | 6.1 Meter |

Line conductor to poles and other projections. | 2.4 Meter | 2.7 Meter | 2.7 Meter | 3.0 Meter | 3.7 Meter | 5.5 Meter |

Line conductor to any other wire other than traction wires. | 1.8 Meter | 1.8 Meter | 1.8 Meter | 2.4 Meter | 3.0 Meter | 3.7 Meter |

### Clearances of Electrical Line to Fuel Tanks>

Description of Clearance |
0.4 KV |
11 KV |
33KV |
110KV |
220 KV |
400KV |

Horizontal clearance from line conductors to petrol tanks and vents | 15 Meter | 15 Meter | 15 Meter | 15 Meter | 15 Meter | 15 Meter |

Horizontal clearance from line conductors to liquid gas tanks | ||||||

(1) 459 to 2273 litre capacity |
3.0 Meter | 3.0 Meter | 3.0 Meter | 3.4 Meter | 4.6 Meter | 5.3 Meter |

(2) 2274 to 9092 litre capacity |
7.6 Meter | 7.6 Meter | 7.6 Meter | 7.6 Meter | 7.6 Meter | 7.6 Meter |

(3) More than 9093 litre. |
15 Meter | 15 Meter | 15 Meter | 15 Meter | 15 Meter | 15 Meter |

Vertical clearance from line conductors to fuel oil tanks | Please refer Clearances to Objects |

### Clearances of Electrical Lines to other Electrical Lines

Description of Clearance |
0.4 KV |
11 KV |
33KV |
110KV |
220 KV |
400KV |

Lowest line conductor or earth wire of upper line to highest line conductor of lower line. | 1.0 Meter | 1.8 Meter | 2.0 Meter | 2.5 Meter | 3.7 Meter | 4.4 Meter |

Lowest line conductor or earth wire of upper line to earth wire of lower line where erected. | 0.7 Meter | 1.4 Meter | 1.6 Meter | 2.5 Meter | 3.7 Meter | 4.4 Meter |

Lowest line conductor or earth wire of upper line to any point on a support of the lower line on which a person may stand. | 2.7 Meter | 2.8 Meter | 3.0 Meter | 3.4 Meter | 4.6 Meter | 5.3 Meter |

Support of upper line and any conductor of lower line. | 7.5 Meter | 7.5 Meter | 7.5 Meter | 15 Meter | 15 Meter | 15 Meter |

### Vertical Passing Clearance (sites where vehicles will pass below the lines)

Description of Clearance |
<33 KV |
110KV |
220KV |
400 KV |

Passing clearance: fixed height loads | 0.8 Meter | 1.4 Meter | 2.4 Meter | 3.1 Meter |

Passing Clearance: variable height loads. | 2.3 Meter | 3.2 Meter | 4.1 Meter | 5.0 Meter |

### Horizontal Clearance (sites where there will be no work or passage of plant under lines)

Description of Clearance |
<33 KV |
110KV |
220KV |
400 KV |

Minimum horizontal distances to safety barriers | 6.0 Meter | 9.0 Meter | 12.0 Meter | 14.0 Meter |

### Distance between Conductors of Same/Different Circuit (On Same Support)

Higher Voltage of either Circuit |
Lower Voltage of either Circuit |
Distance between Circuits |

< 33 KV | < 1 KV | 1.0 Meter |

< 33 KV | > 1 KV | 1.2 Meter |

33 KV to 110 KV | < 1 KV | 1.5 Meter |

33 KV to 110 KV | > 1 KV | 2.0 Meter |

Above 110 KV | All | 2.5 Meter |

### Vertical Distance between Conductors of different Circuit (On Different Support)

Higher Voltage of either Circuit |
Distance between Circuits |

< 1 KV | 0.6 Meter |

1 KV to 33 KV | 1.2 Meter |

33 KV to 66 KV | 1.8 Meter |

110 KV | 2.4 Meter |

220 KV | 2.8 Meter |

### Distance between Conductors (Taken down from Pole to other Support, on Transformer)

Voltage |
Distance between Circuits |

11 KV & LV Line | 0.60 Meter |

22 KV & LV Line | 0.75 Meter |

33 KV & LV Line | 0.90 Meter |

### Horizontal Distance of Telecommunication Line & Overhead Line

Description of Clearance |
Distance |

Telecommunication Line(Not insulated) to HV Line | Min 1.6 Meter |

Telecommunication Line (Bare) to LV (Bare) Line | Min 1.2 Meter |

Telecommunication Line (Covered) to LV (Bare) Line | Min 0.6 Meter |

Telecommunication Line (Bare) to Stay (Bare) Wire | Min 0.3 Meter |

### Passage Way for Metal-Clad Switchgear

Description of Clearance |
Distance |

Clean &unobstructed Passages at the front of any Low/High Voltage Switchgear. | 1.0 Meter wide & 2.5 Meter high |

Clean &unobstructed Passages at side or under any earthed enclosure containing Bare Conductor | 0.8 Meter wide & 2.2 Meter high |

### Safe approach distance for Person from Exposed Live Parts

Circuit Voltage |
Distance |

< 1 KV | 0.5 Meter |

11 KV | 1.5 Meter |

22 KV | 2.0 Meter |

33 KV | 2.5 Meter |

66 KV | 3.0 Meter |

110 KV | 4.0 Meter |

>220 KV | 6.0 Meter |

Ajit kumar.thakor

Pl Suggest Neared by 66 kva O/H Line .

Telecom tower 30 meter height erected neared by 6 meter is it sufficient space?

As per IE stranded How much space require.

Kandarpa Kalita

Whether living in a house under a 11 KV power line will be safe ? Kindly let me know. I propose to buy a plot where such a line passes. Whether living near such line ( not exact;y below ) is also harmful ?

Pl let me know.

K Kalita

Guwahati , Assam

Nijanthan

Can a 400kv transmission line be place 3 meters from a house and also can it pass through plots and residental area.

amit

we need to construct chain link fencing in switch yard, where we have power transformers example 132 kv,140 MVA,so i need to know how much horizontal clearance should be maintained between transformer and fence

Bhrigu Kumar Nath

hi,

i have searched many Indian Standards but could not find horizontal Clearance distance between two parallel transmission line (esp. 400 kV and 220 kV). Would you help me in giving me the Standards or the distance?

Djai

Hi,

I am involved in a project where we are connecting a HV line into a substation. Now to do that we have two options:

1- We need to go parallel to a gas pipeline for about 2 km, and as a result block any other future lines i.e. they would have to cross existing lines

2- We need to go over HV power transformer and gas generator containers

Problem is we do not have a specific standard to follow.

Help please.

Rgds,

Djai

P.Chengal Reddy, Farmers activist

Please let me know the distance require near 400 KV transmission line and for construction of 3 stories business building .If possible speak to me .it is urgent

Regards

P. Chengal Reddy , Hyderabad

98495 12600

sareerahmad

Please give some reference from NESC for the clearance of transmission lines. That will also help us in finalizing the design. NESC is internationally accepted standard.

haytham sabry

Thank you

eepower

Thank you