What are the 3 basic measures used to avoid electric shock?

• A. Isolation, Insulation, Ground
• B. Containment, Shielding, Bonding
• C. Isolation, Bonding, Grounding
• D. Containment, Grounding, Insulation

Answer: (A)

The key idea is the three fundamental ways to keep someone from getting shocked: isolation, insulation, and grounding. Isolation means removing the energizing source or physically separating the hazard from people so exposed conductors aren’t reachable. Insulation involves using nonconductive barriers and materials to prevent current from passing through a person if contact occurs. Grounding provides a low-impedance path for fault current to flow to earth, keeping exposed conductive parts at earth potential and enabling protective devices to trip quickly to stop the shock.

Note that “ground” and “grounding” are often used interchangeably in practice, and both refer to the same safety goal of directing fault current away from people and towards the earth.