Low voltage 48 VDC current under fault conditions in electrical equipment could pose which of the following electrical hazards? a. Arc blast b. Arc flash c. Electric shock d. Thermal burn
The correct answer and explanation is:
The correct answer is: c. Electric shock
Explanation:
Low voltage systems such as 48 VDC are generally considered safer than higher voltage systems regarding the risk of arc flash and arc blast. These hazardous events typically occur at higher voltages where the electrical energy is sufficient to cause explosive electrical arcs or flashes.
At 48 volts DC, the primary hazard under fault conditions is electric shock. Electric shock happens when current flows through the body, potentially causing injury or even fatality, depending on the amount of current and duration of contact. Although 48 VDC is considered low voltage, it can still deliver enough current to cause a harmful or painful shock, especially if the skin is wet or if there is a direct contact with conductive parts.
Arc blast and arc flash hazards are more common at higher voltages, usually above 120 volts AC, where the energy released can cause burns, intense light, and pressure waves that injure workers. Similarly, thermal burns can occur if there is prolonged contact with heated equipment or conductors, but these burns are less likely under low voltage fault conditions unless there is physical contact with heated components caused by electrical faults.
In summary, for a low voltage system like 48 VDC, the main electrical hazard under fault conditions is electric shock due to current flowing through a person’s body. Proper safety measures such as insulation, protective equipment, and careful handling are essential to prevent this hazard. Although the risk of arc flash, arc blast, and thermal burns is minimal at this voltage, these hazards cannot be entirely ruled out at higher voltages. Understanding the specific risks associated with different voltage levels helps ensure safe handling and maintenance of electrical equipment.