NEC Quiz: Article 240 Answers

by Mark Lamendola

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  1. [240.4(A)]. This is a trick question. Actually, you don't install OCPDs on a fire pump (see Article 695). OCPDs aren't required where interruption of the circuit would cause a hazard.
     

  2. [240.4(G)]. Yes. See Table 240.4(G).
     

  3. [240.12]. They are coordinated short-circuit protection and overload indication based on monitoring systems or monitoring devices.
     

  4. [240.30(A)(1)]. Install them in enclosures, cabinets, cutout boxes, or equipment assemblies; or
    Mount them on open-type switchboards, panelboards, or control boards that are in rooms free from dampness (and from easily ignitable material) and are accessible only to qualified personnel.
     

  5. [240.93(C)]. You can't use it if:
    1. Motors are connected on the load side of the higher-rated OCPD and on the line side of the lower-rated OCPD, and
    2. The sum of the motor full-load currents exceeds 1 percent of the interrupting rating of the lower-rated OCPD.