Which statement best describes the relationship between a residual current device (RCD) and a GFCI?

Which statement best describes the relationship between a residual current device (RCD) and a GFCI?

• A. An RCD detects imbalance between live and neutral currents and trips; GFCI is a type of RCD used in North America; both provide shock protection, but terminology varies by region.
• B. An RCD protects against overvoltage; GFCI does not provide shock protection.
• C. An RCD is used only for DC systems; GFCI is used for AC only.
• D. An RCD and GFCI are identical with no regional terminology difference.

Answer: (A)

The key idea is that both devices protect against electric shock by watching for leakage current. They monitor the same current flowing in the live and neutral conductors, and if some current escapes to earth, an imbalance appears. When this happens, the device trips and cuts power quickly. A GFCI is a specific type of RCD widely used in North America; in many other regions the same protection is simply called an RCD (or RCCB). So they describe the same protective function, with regional naming differences. The other statements misstate the function (overvoltage protection), the applicability to DC versus AC, or imply there’s no regional naming difference.

The key idea is that both devices protect against electric shock by watching for leakage current. They monitor the same current flowing in the live and neutral conductors, and if some current escapes to earth, an imbalance appears. When this happens, the device trips and cuts power quickly. A GFCI is a specific type of RCD widely used in North America; in many other regions the same protection is simply called an RCD (or RCCB). So they describe the same protective function, with regional naming differences. The other statements misstate the function (overvoltage protection), the applicability to DC versus AC, or imply there’s no regional naming difference.