Wiring and componentsQuestion 805 of 1506

How are busbars usually made and supported?

  1. Bare copper or aluminum bars on insulating standoffs
  2. Insulated lead bars glued to a wall with no standoffs
  3. Twisted pair wire in a conduit
  4. Stranded steel wire on wooden posts
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Correct answer: Bare copper or aluminum bars on insulating standoffs

Busbars are uninsulated, so they must be held away from metal frames by insulators.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 12.2: Conductor Size

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Questions last reviewed: 18 October 2026