This is an online course for general workers with clear, non-technical language and a focus on practical recognition and protection. By the end of this program, you will learn;
How Electricity Can Kill and Other Hazards
This lesson explains that electricity is dangerous because the human body is a good conductor of current. It covers the physical effects of shock and the common ways accidents happen.
Key Learning Points:
The Human Circuit: A shock occurs when your body becomes part of a path for electricity to reach the ground.
The “Let-Go” Threshold: At certain current levels (approx. 10–30 mA), muscles contract so violently that a person cannot let go of the wire, prolonging the shock.
Internal & External Damage: Beyond heart failure (ventricular fibrillation), electricity causes deep internal tissue burns that may not be visible on the skin initially.
Secondary Hazards: Shocks can cause muscle spasms that throw a worker off a ladder or scaffold, leading to falls.
Understanding AC vs. DC Safety
This lesson clarifies the two types of current found in the workplace and why they behave differently when they contact the body.
Key Learning Points:
AC (Alternating Current): Found in wall outlets and power lines. It reverses direction 50–60 times per second. It is generally more dangerous at common voltages because it “grabs” the victim through rapid muscle contractions.
DC (Direct Current): Found in batteries, solar panels, and electric vehicles. It flows in one direction. While often considered “safer” at low levels, high-voltage DC is extremely dangerous because it causes a single, powerful contraction and can cause severe continuous internal heating.
Resistance: Wet skin significantly lowers your body’s resistance, making both AC and DC much more lethal.
Protection Devices (GFI, ELCB, and RCD)
This lesson teaches workers how to recognize and use safety devices designed to cut power before a shock becomes fatal.
Key Learning Points:
GFCI (Ground Fault Circuit Interrupter): A fast-acting device that monitors current balance. If it detects a “leak” (like current flowing through a person), it shuts off power in 1/40th of a second.
ELCB (Earth Leakage Circuit Breaker): An older type of safety switch that detects voltage on the metal frames of equipment. It is largely being replaced by modern RCDs.
RCD (Residual Current Device): The modern standard for “Safety Switches” that provides broad protection against leakage current to the ground.
Testing: These devices must be tested regularly using the “Test” button to ensure the internal mechanism still works.
Personal Protective Equipment (PPE) and Safe Maintenance
This lesson teaches workers how to choose, inspect, and use the correct gear to prevent contact with live electricity. PPE is the “last line of defense” when other safety measures fail.
Key Learning Points:
Voltage-Rated Gloves: Standard work gloves provide zero protection against electricity. Specialized rubber insulating gloves are classified by the maximum voltage they can handle (e.g., Class 00 for up to 500V AC).
Leather Protectors: Always wear leather gloves over your rubber insulating gloves to protect the delicate rubber from punctures or tears.
Insulated Footwear: Look for “EH” (Electrical Hazard) rated boots with non-conductive rubber soles to prevent a shock path from your body to the ground.
Arc-Rated (AR) vs. Flame-Resistant (FR) Clothing: Not all fire-resistant clothes protect against electrical “arc flashes” (explosive bursts of heat). Ensure clothing is specifically “Arc-Rated” for the energy level of the equipment.
Pre-Use Inspection: Before every use, air-test rubber gloves by rolling them up to trap air and listening for leaks. Even a pinhole can allow a lethal current to pass through.
