Which IEC category is described as Receptacle outlet circuit; plug-in loads?

• A. II - Receptacle outlet circuit; plug-in loads
• B. I - Protected Electronic circuits
• C. III - Distribution wiring including mains
• D. IV - Origin of installation at the Utility level

Answer: (A)

In IEC surge protection categories, categories describe where protection sits along the path from the utility to the device. Category II is the level that covers receptacle outlet circuits and plug-in loads—the energy that flows through wall outlets to consumer devices. This includes things like power adapters, lamps, and appliances that you plug into a regular outlet.

Category II sits after the main distribution but before the devices themselves, which is why it’s described as receptacle outlet circuits and plug-in loads. The other levels cover different parts of the system: Category I relates to protected electronic circuits not directly tied to mains; Category III covers distribution wiring inside the building including mains and panels; Category IV refers to the origin at the utility service entrance. So the description fits Category II precisely.