E L E C T r I C I T Y I S DA N G E r O U S
This manual will present many topics. There are four main types of electrical injuries: electrocution (death due to electrical shock), electrical shock, burns, and falls. The dangers of electricity, electri- cal shock, and the resulting injuries will be discussed. The various electrical hazards will be described. You will learn about the safety model, an important tool for recognizing, evaluating, and control- ling hazards. Important definitions and notes are shown in the mar- gins. Practices that will help keep you safe and free of injury are emphasized. To give you an idea of the hazards caused by electricity, case studies about real-life deaths will be described.
❚ current—the movement of electrical charge
❚ voltage—a measure of electrical force
❚ circuit—a complete path for the flow of current
❚ You will receive a shock if you touch two wires at different voltages at the same time.
How Is an Electrical Shock received?
An electrical shock is received when electrical current passes through the body. Current will pass through the body in a variety of situations. Whenever two wires are at different voltages, current will pass between them if they are connected. Your body can connect the wires if you touch both of them at the same time. Current will pass through your body.
Wires carry current
❚ ground—a physical electrical connection to the earth
❚ energized (live, “hot”)—similar terms meaning that a voltage is present that can cause a current, so there is a possibility of getting shocked
In most household wiring, the black wires and the red wires are at 120 volts. The white wires are at 0 volts because they are connected to ground. The connection to ground is often through a conducting ground rod driven into the earth. The connection can also be made through a buried metal water pipe. If you come in contact with an