1) Electrical shocks occur when electrical current passes through the body, such as touching a live wire and an electrical ground or two wires at different voltages. 2) Electrical injuries can be direct, such as electrical shock, burns, or internal damage from involuntary muscular contractions, or indirect from falls which account for 30% of electrocutions. 3) The probability of effects from electrical shocks range from a slight tingling sensation at 1mA to cardiac arrest and probable death at 10,000mA.

1. Sub-Station Equipment
Electrical Safety

2. INTRODUCTION
An electrical shock is received when
electrical current passes through the body.
You will get an electrical shock if
•a part of your body completes an electrical
circuit by…
•Touching a live wire and an electrical
ground, or
•Touching a live wire and another wire at a
different voltage

3. Electrical Injuries
• Direct:
Electrical shock;
Burns;
Internal Damages;
Involuntary muscular contraction;
• Indirect – Falls
(30 % of Electrocutions are accompanied by
fall)

4. Dangers of Electrical Shock
Current
level
(in mA)
Probable effect on human body
1 mA Perception level. Slight tingling sensation. Still dangerous
under certain conditions.
5 mA Slight shock felt; not painful but disturbing. Average
individual can let go. However, strong involuntary reactions
to shocks in this range may lead to injuries.
6-30 mA Painful shock, muscular control is lost. This is called the
freezing current or "let-go" range
50-150 mA Extreme pain, respiratory arrest, severe muscular
contractions. Individual cannot let go. Death is possible.
1000-4300
mA
Ventricular fibrillation (the rhythmic pumping action of the
heart ceases.) Muscular contraction and nerve damage occur.
Death is most likely.
10,000 mA Cardiac arrest, severe burns and probable death.

5. Causes of Electrical Injuries
• Unauthorized operation
• without or improper Earthing
• Improper Fuses
• Single insulated Cable (s)
• Improper Cable Joints
• Hanging Cables
• Without Plug Top
• DBs without protection against rain & curing water

6. Earthing
• All the Electrical equipment
shall be grounded;
• DB’s shall be provided with
double earthing;
• Earthing conductor shall be
capable of carrying of
maximum current;

7. Fuses
• Fuses are proven safety devices for
overload conditions
• Check the fuses for their current
ratings
• Never replace fuse wire with
ordinary copper or aluminium wire
• High rupturable cartridge (HRC)
fuses are now a days easily
available and has advantages over
traditional fuses

8. Cable Joints
– Joints are not to be overlapped
– One primary insulation and an overall secondary
insulation is to be done
– Proper insulation tape are to be used
And Not this

9. PPE ‘s

10. First AID – Electric Shock
• Don’t become the next victim;
• Isolate the victim from the Circuit;
– Disconnect the power supply;
– Use Insulators;
• High Voltage lines contacts are usually fatal,
better seek help from experts.
• Check for breathing;
– Artificial Respirations
• Check for pulse;
– Cardiac resuscitation

11. THANK YOU