Practice Test Geeks(E2) E2 Commercial Electrical Inspector Practice Test
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Systems and Equipment Flashcards

7 cards from real E2 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Systems and Equipment flashcards as text

  1. According to the NEC, what is the minimum clearance required above a switchboard in a commercial installation?

    Answer: 6 feet

    NEC 110.26(A)(1) requires a minimum of 6 feet of headroom above electrical equipment such as switchboards.

  2. A commercial building's emergency lighting system is required to provide illumination for at least how long upon loss of normal power?

    Answer: 90 minutes

    NEC 700.12 requires emergency lighting systems to provide at least 90 minutes of operation upon normal power failure.

  3. When inspecting a variable frequency drive (VFD) installation, which conductor issue is most critical to verify?

    Answer: Conductor ampacity derating for harmonic heating

    VFDs produce harmonics that cause additional heating in conductors, requiring ampacity derating per NEC 310.15(A)(2).

  4. Under the NEC, a motor controller must be capable of interrupting the stalled-rotor current of the motor it controls. This rating is known as the:

    Answer: Locked rotor current (LRC)

    Motor controllers must be rated for locked rotor current (LRC), which is the maximum current drawn when the motor shaft is stalled.

  5. In a commercial kitchen, a dishwasher is hardwired to a 20-ampere, 120-volt circuit. The NEC requires this circuit to be protected by a:

    Answer: Standard GFCI breaker

    NEC 210.8(B) requires GFCI protection for commercial kitchen equipment in areas where water is present.

  6. What does the NEC require for grounding electrode conductors at a commercial service entrance that uses a metal water pipe as a grounding electrode?

    Answer: A supplemental electrode must also be installed

    NEC 250.53(D)(2) requires a supplemental grounding electrode when a metal water pipe is used as a grounding electrode.

  7. A rooftop HVAC unit on a commercial building is served by a disconnect switch mounted on the unit. The NEC requires this disconnect to be:

    Answer: Lockable in the open position

    NEC 430.102(B) and 440.14 require the disconnecting means for HVAC equipment to be lockable in the open (off) position.