How would you verify the polarity of a newly installed single-phase receptacle?

• A. Visual inspection only.
• B. Use a polarity tester or multimeter to verify hot to brass, neutral to silver, earth to green.
• C. Measure resistance across live and earth.
• D. Use a clamp meter around each conductor.

Answer: (B)

Verifying polarity hinges on confirming that the hot, neutral, and earth are connected to their correct terminals. For a single-phase receptacle, that means the hot conductor should be on the brass-colored terminal, the neutral on the silver-colored terminal, and the earth/ground on the green terminal. Using a polarity tester or a multimeter provides a direct check of this mapping. A polarity tester plugs into the outlet and shows quick status indicators indicating whether hot is on the correct blade, neutral on its blade, and the earth connected properly. Alternatively, with a multimeter you can measure voltages: hot-to-neutral should read the supply voltage, hot-to-earth should read approximately the same voltage, and neutral-to-earth should be near zero. This confirms the intended connections and catches reversed or swapped wiring, which can create shock hazards or improper operation of connected devices.

Relying on a visual inspection isn’t enough because wiring can look correct yet be mixed up inside the box. Measuring resistance between live and earth isn’t a valid or safe way to verify polarity once power is present, and a clamp meter around conductors measures current, not the identity of the conductors or their arrangement. Using the proper tester or a multimeter gives a clear, safe check of the outlet’s wiring state and helps prevent hazards.