INTRODUCTION
Modern society has produced several generations who have grown accustomed to electric�ity. This acclimatization has been made easier by the fact that electricity is silent, invisible,odorless, and has an “automatic” aspect to it. In the late 1800s, hotels had to place signs assuring their guests that electricity is harmless. By the late 1900s, signs had to be hung to remind us that electricity is a hazard. In fact, the transition of electricity from a silent coworker to a deadly hazard is a change that many cannot understand until it happens to them. Because of these facts, the total acceptance of an electrical safety procedure is a requirement for the health and welfare of workers.
Understanding the steps and procedures employed in a good electrical safety program requires an understanding of the nature of electrical hazards. Although they may have trou�ble writing a concise definition, most people are familiar with electric shock. This often painful experience leaves its memory indelibly etched on the human mind. However, shock is only one of the electrical hazards. There are two others—arc and blast. This chapter describes each of the three hazards and explains how each affects the human body.
Understanding the nature of the hazards is useless unless protective strategies are devel�oped to protect the worker. This chapter also includes a synopsis of the types of protective strategies that should be used to protect the worker.
Arc (electric)
The heat and light energy release that is caused by the electrical breakdown of and subsequent electrical discharge through an electrical insulator, such as air.
Arc energy input
The total amount of energy delivered by the power system to the arc. This energy will be manifested in many forms including light, heat, and mechanical (pressure) energy.
Arc incident energy
The amount of energy delivered by an electric arc to the clothing or body of a worker. This amount of energy will be somewhat less than the arc energy based on factors in the workplace.
Arc-resistant Metal-clad switchgear which features strengthened mechanical switchgear construction as well as pressure relief systems. Arc-resistant switchgear is designed to minimize the probability of an arc-flash as well as contain the energy in the event that one occurs
