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 |
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Jignesh Parmar
Electrical Middle management professional having more than 22 years rich and dynamic experience in Project Execution / Project Management / Designing / Maintenance diversifies from Electrical Power Transmission (400KV/220KV/66KV)- Distribution(11KV/220V) to Lifts-HVAC-Ventilation-Fire Fighting-Fire Alarm-Lifts-CCTV-Stack Parking Works (High Rise Buildings, Townships, Shopping Complex, Commercial Complex, School, Temple).Profile: Jignesh Parmar
Dear Sir,
Please share the above referred standard “NIE 6/025 ENA” for educational purpose. I will be very thankful to you.
It is indeed satisfying to see the data for electrical clearances and many more information for my applications in general.
Thanks
What is the allowable maximum distance for an 11kv, 22kv, 33kv & 66kv to be run (kilometers)?
Or is it safe to Construct a 22kv line over 280km?
were i can get 22kv clearance and cross arm and other details ?
Hi Sir, Great ,Highly Appreciable for the valuable technical specifications as part of Electrical Safety Aspects. certainly, helpful for give needful awareness among our Team.
Thanks & Regards,
Ganesan.K
Ex. Indian Army, Sr. Manager-HSE
9380673686
i appricate your information , just i want to no if it possible to have 230 kv cable inside pvc under 230 kv power transformer and if there is clearance distance or not .
Please could you tell me what is the minimum distance between the transmission lines of AT (220 kV) and wind turbine (wind turbines)
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.
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
Can a 400kv transmission line be place 3 meters from a house and also can it pass through plots and residental area.
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
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?
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
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
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.
Thank you
Thank you