Effects of High Voltage on Human body; High voltage effects on Human Body

By -

Effects of High Voltage on the Human Body: Risks, Mechanisms, and Real-Life Incidents

Electricity is one of the most useful forms of energy, but it comes with inherent dangers—especially when dealing with high voltage systems. While household voltage (110–240V) can already be life-threatening, exposure to high voltages (above 1,000V AC or 1,500V DC) dramatically increases the severity of the risks. Understanding how high voltage affects the human body is critical for electrical engineers, workers, and the general public to ensure safety.



What is Considered High Voltage?

  • Low voltage (LV): Up to 1 kV AC (or 1.5 kV DC)

  • High voltage (HV): 1–33 kV (commonly used in distribution lines)

  • Extra-high voltage (EHV): Above 33 kV, used in long-distance transmission lines

Even though the threshold for high voltage starts at 1 kV, the human body can be severely harmed at voltages as low as 50V AC if the current path passes through vital organs.

How High Voltage Affects the Human Body

The severity of electric shock depends on four main factors:

  1. Voltage level – Higher voltage increases the potential for breakdown of skin resistance.

  2. Current path – Current through the chest (hand-to-hand or hand-to-foot) can disrupt the heart and lungs.

  3. Duration of contact – Longer exposure means greater internal damage.

  4. Frequency – AC at 50–60 Hz is particularly dangerous because it aligns with the frequency range of nerve and heart muscle excitation.

Key Physiological Effects:

  • Breakdown of Skin Resistance: At high voltages (>500V), the insulating properties of human skin collapse, allowing massive current to flow through tissues.

  • Muscle Contraction & “Lock-On Effect”: Victims may not be able to let go of a conductor due to involuntary muscle contraction.

  • Cardiac Arrest & Ventricular Fibrillation: Even a current of 100 mA through the chest can cause the heart to stop.

  • Burns and Tissue Damage: High voltage arcs cause deep burns, often requiring amputation.

  • Neurological Damage: Nerve tissues may be permanently damaged, leading to paralysis.

Real-Life Examples of High Voltage Accidents

1. Transmission Line Accidents

Many electrical workers and linemen face fatal accidents while working on 11 kV or 33 kV distribution lines without proper isolation. A momentary lapse in safety—such as touching a live conductor—can lead to instant death due to current passing through the body.

2. Railway Electrification Systems

India’s railway traction system operates at 25 kV AC overhead lines. Several unfortunate incidents have occurred where individuals climbing on train roofs came into contact with live wires. Even without touching the conductor, high-voltage arcs (flashovers) can jump across a small distance, causing severe burns or fatal injuries.

3. Industrial Substations

In substations, faults or poor insulation may lead to arc flashes—high-energy discharges that can project molten metal and cause third-degree burns. For example, workers in a 66 kV switchyard have reported injuries not from direct contact, but from standing near an arc blast.

4. Lightning Strikes (Nature’s High Voltage)

Lightning is a natural high-voltage phenomenon, with voltages exceeding 100 million volts. Survivors often suffer neurological issues, memory loss, or cardiac complications long after the strike.

Safety Measures Against High Voltage Hazards

  • Maintain Safe Distance: Never approach overhead transmission lines, even if they appear insulated.

  • Use Insulated Tools & PPE: Rubber gloves, helmets, and dielectric boots are mandatory for linemen.

  • Proper Earthing & Isolation: Always ground high-voltage equipment before maintenance.

  • Lockout-Tagout (LOTO): Ensure complete disconnection before working on circuits.

  • Training & Awareness: Workers should be educated on the “step and touch potential” near substations and towers.

Conclusion

High voltage electricity is indispensable for modern power systems but poses severe risks to human life. From burns and paralysis to fatal cardiac arrest, its effects can be instantaneous and devastating. Real-life cases—from railway overhead line accidents to lightning strikes—highlight the importance of strict safety protocols and awareness.

Electricity does not forgive mistakes. By respecting its power and adhering to engineering safety standards, we can prevent accidents and save lives.

✅ Disclaimer: This article is for educational purposes only. High-voltage systems are extremely dangerous—never attempt to handle or approach them without professional training and authorization.


Comments

Post a Comment

Popular posts from this blog

A2XWY; A2XFY Cables meaning; XLPE cables advantages over PVC cables

By -
Image
🏗 ️ Technical Specification of Aluminium Cables (IS 7098: Part 1 – 1988) When specifying aluminium cables, you will often come across codes like A2XWY . This code represents the construction, insulation, armouring, and sheath of the cable. 🔑 Cable Nomenclature Codes Code Meaning A Aluminium Conductor 2X XLPE (Cross-linked Polyethylene) Insulation Y PVC Outer Sheath W Steel Round Wire Armour F Steel Strip Armour WW Double Steel Round Wire Armour FF Double Steel Strip Armour Wa Non-Magnetic Round Wire Armour Fa Non-Magnetic Strip Armour AW Aluminium Wire Armour 👉 Example: A2XWY = Aluminium conductor + XLPE insulation + Steel round wire armour + PVC outer sheath. 📌 Note: For Copper Cables , no pref...
Read more

YWY, AYFY, AYY, AYCY, A2XCY Cables Meanings

By -
Image
📘 Cable Nomenclature Explained (PVC & XLPE Cables) Cable designations like YWY, AYFY, A2XCY might look confusing at first glance. But once you understand the logic behind each letter , reading technical specs becomes straightforward. 1. Basic Conductor Material ·          A → Aluminium conductor ·          (If “A” is absent, it means Copper conductor) 2. Insulation Material ·          Y → TROPODUR = PVC insulation ·          2X → TROPOTHEN-X = XLPE insulation 3. Armouring Types ·          W → Round Steel Wire Armouring ·          WW → Double Round Steel Wire Armouring ·          F → Flat (formed) Steel Strip Armouring ·       ...
Read more

Cable size and current carrying capacity

By -
Image
Cable size and current carrying capacity for XLPE insulated cable, non-armored, Twin or multicore cable is as below:- Conductor operating temperature is 90 degree Celsius Ambient temperature: 30 degree Celsius. Cable size and current carrying capacity for XLPE insulated, Armored, Twin or multicore cable is as below:- Conductor operating temperature is 90 degree Celsius Ambient temperature: 30 degree Celsius. For air and 20 degree Celsius for ground for installations require to comply with BS: 7671 Correction factors:- For Ambient temperature: Ambient temperature in degree Celsius Correction Factor 25 1.02 30 1.00 35 0.96 40 0.91 45 0.87 50 0.82 55 0.76 60 0.65 65 0.58 70 0.50 75 0.41 80 Ground Temperature Ambient temperature in degree Celsius Correction F...
Read more