How do you determine if a circuit requires RCD protection by regulations?

• A. RCD protection is always optional.
• B. Regulations and risk assessment; many circuits require RCD protection in domestic installations.
• C. RCD protection is only for outdoor circuits.
• D. RCDs are only for industrial premises.

Answer: (B)

RCD protection is determined by safety regulations and by a risk assessment of how the installation will be used. The idea is to check what the rules require and also consider the real risk of electric shock in the given situation. In a domestic installation, regulations typically mandate RCD protection for many circuits—especially socket outlets, outdoor circuits, and other areas where dampness or contact with liquid increases shock risk. A risk assessment helps decide where extra protection is needed beyond the basic rules, ensuring circuits that pose higher hazards are covered. The other statements miss the reality that RCD protection is not universally optional, is not limited only to outdoor circuits, and is not something that applies only to industrial premises.