Practice question

What component in a NEMA cabinet provides the AC-line isolation point and is required to remove all 120 VAC field output power for safe bench work on the back panel?

  1. The CMU/MMU reset button
  2. The police panel auto/flash switch
  3. The signal bus main circuit breaker (or main disconnect)
  4. The detector rack power switch

Answer: C — The signal bus main circuit breaker (or main disconnect)

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