Final answer:
The NFPA 70E standard prioritizes the elimination of electrical hazards, with an emphasis on using a hierarchy of risk control methods when elimination is not feasible. Safety systems like circuit breakers, fuses, and the three-wire grounding system are critical for preventing thermal and shock hazards. Plastic insulation on live/hot wires is used to prevent both shock and thermal hazards by providing a protective barrier.
Step-by-step explanation:
The NFPA 70E standard considers elimination to be the first priority when addressing electrical hazards. This means identifying potential sources of electrical danger and removing them entirely as the foremost method of hazard prevention.
When elimination is not possible, the standard outlines a hierarchy of risk control methods, including substitution of less hazardous materials or processes, engineering controls to isolate people from the hazard, awareness through warning labels or signs, administrative controls like safety practices and procedures, and finally, the use of personal protective equipment (PPE) as a last line of defense.
Electrical safety systems and devices are essential in mitigating risks where hazards cannot be completely eliminated. Devices such as circuit breakers and fuses are utilized to prevent thermal hazards by interrupting excessive currents.
Additionally, the three-wire grounding system is an effective measure that guards against both thermal and shock hazards by using live/hot, neutral, and earth/ground wires to ensure appropriate grounding of the neutral wire and the case of the appliance.
Plastic insulation on live/hot wires is a preventive measure against both shock and thermal hazards. While it serves as a barrier to prevent electric current from passing to a person, which would cause a shock hazard, it also insulates the wires to prevent the overheating and potential thermal dangers that can occur with exposed or damaged wiring. Therefore, employing comprehensive safety systems and awareness of the hazards associated with electricity is paramount to effective electrical safety management.