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In a US three-wire 120 V AC cable, what does black wire insulation mean?

Hot.

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  1. Neutral
  2. Equipment ground
  3. Hot ✔

Why: In US household wiring, black is the hot wire, white is neutral, and green or bare is ground. Treat black as live and dangerous.

Huh, didn't know that: Fuses and breakers in 120 V circuits go in series with the hot wire only.

The dad joke
Why did the black wire get all the attention? It was the hottest one there.
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References

Answer: Hot. In US household wiring, black is the hot wire, white is neutral, and green or bare is ground. Treat black as live and dangerous.

  1. HamStudy 2026-2030 Technician pool, section T0A hamstudy.org/browse/E2_2026/T0A
    Hot
    Checked 2026-10-09.

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