How is fault protection provided?

• A. RCDs, MCBs, overcurrent devices and earthing and bonding
• B. Only fuses and fuses
• C. Voltage stabilizers
• D. Surge protectors

Answer: (A)

Fault protection means stopping harm from electrical faults by quickly removing the supply when something goes wrong. The best way to achieve this is with a combination of protective devices and a proper earthing and bonding system. RCDs monitor the current in the live and neutral conductors and trip if there’s an imbalance, which usually means current leaking to earth—this greatly reduces the risk of electric shock. MCBs provide overcurrent protection, tripping when current is too high due to overloads or short circuits, which helps prevent overheating and fire. Earthing gives fault current a low-resistance path to the earth, so the fault current is large enough to trigger the protective devices and also keeps exposed metal parts at earth potential to reduce touch voltage. Bonding connects exposed or metallic parts to the earth so there aren’t dangerous voltage differences between them. Relying only on fuses, voltage stabilizers, or surge protectors doesn’t deliver this comprehensive fault protection, whereas the combination of RCDs, MCBs, overcurrent devices and earthing and bonding provides the necessary safety.