"10/20 rule" in electrical safety

In Saudi Arabia, electrical safety rules for safe distances (also called Minimum Approach Distances or Clearances) from high voltage overhead power lines are mainly followed from Saudi Electricity Company (SEC) and international practices like OSHA especially for construction, maintenance, and general work.

"10/20 rule" in electrical safety

Many companies in Saudi Arabia (including petrochemical plants like SABIC and ARAMCO) follow similar guidelines, often based on OSHA (1910.333 and 1910.269) standards or slightly stricter internal rules for worker safety.

General Safe Distance Rules 

Up to 50 kV (including 33 kV, 34.5 kV, 69 kV lines) → Minimum 10 feet (≈ 3 meters)

Above 50 kV (69 kV to 230 kV, 380 kV transmission lines) → Minimum 20 feet (≈ 6 meters) or more, depending on exact voltage

380 kV (common in Saudi transmission) → ≈ 8–9 m (26–30 ft) or calculated per IEC

Aramco and SABIC sites usually enforce the 10 ft (50 kV or below) and 20 ft (above 50 kV) rule very strictly for all non-electrical work.

Cranes, excavators, trucks, scaffolding, etc. must maintain these distances — many serious accidents happen due to violation.

Always follow the "10/20 rule" electrical safety as a safe starting point, and never take chances — electricity does not give second chances! If in doubt, stop work and consult site safety officer.

Why can you get an electric shock from high-tension (HT) wires even without touching them?

High-tension power lines carry extremely high voltage, which creates a very strong electric field around the wires. This field is so powerful that it can ionize (break apart) the air molecules nearby, turning normal insulating air into a partial conductor. This process is called air ionization or corona discharge.

Under normal conditions, air is an excellent insulator and prevents electricity from flowing through it. But when the voltage is high enough, the electric field strips electrons from air molecules, creating charged particles (ions). This makes the air slightly conductive, especially during humid/wet weather.

How Electricity Reaches Your Body Without Direct Contact

When a person (or any grounded object like a crane, ladder, or even a tall person standing on the ground) gets too close to a high-voltage line, the huge voltage difference between the wire (high potential) and the ground (zero potential through your body) causes the electric field to become extremely intense.

This can lead to:

• Electric Arc (or Arc Flash): Electricity "jumps" through the air in a bright, hot plasma channel (like a mini lightning bolt). The arc can bridge the gap between the wire and your body, delivering a severe or fatal shock, severe burns, or explosion-like energy.
• The arc doesn't need you to touch the wire — it forms when the air breaks down and creates a conductive path.

How Close is Too Close? Approximate Arcing / Danger Distances

The exact distance where an arc can jump depends on factors like voltage, humidity, altitude, air pressure, and pollution. But here are approximate safe approach distances (where arc risk becomes serious) commonly referenced in safety guidelines (these are rough for general awareness; always follow local standards like SABIC, ARAMCO, OSHA):

1. 11 kV → Danger starts around 30–60 cm (about 1–2 feet)
2. 33 kV → Around 1 meter (3–4 feet)
3. 132 kV → 2–3.5 meters (6–11 feet)
4. 220–400 kV (common transmission lines) → 4–7 meters (13–23 feet) or more

These are not exact "arc jump" distances (which can be shorter in bad conditions), but practical minimum approach distances where the risk of shock or arc without touching is very high. For unqualified people, many utilities recommend staying much farther, always follow "10/20 rule" in electrical safety.

Real-life example: Crane operators or workers with long tools often get shocked or killed when the boom or tool gets within a few meters of 132 kV or 400 kV lines — the arc jumps the remaining gap.

Safety Rule to Remember

• "The closer you go, the shorter your life becomes."
• High-voltage electricity doesn't wait for you to touch it — it can reach out and grab you through the air!
• Stay far away from overhead power lines.
• Assume all lines are live and dangerous.

Conclusion 

If work must be done near them, get proper clearance, use qualified personnel, and follow strict safety protocols (permits, PPE, spotters).

Electricity is invisible, silent, and unforgiving — respect the distance, respect life! ⚡

Always follow "10/20 rule" in electrical safety