Test your knowledge of the National Electrical Code (NEC).
Created by: Michael Johnston
1. The NEC indicates which electrical systems are required to be grounded, which systems are permitted to be grounded, and which systems are not permitted to be grounded.
2. The term ______ means connected to ground or to a conductive body that extends the ground connection.
A. Bonded (bonding)
B. Grounded (grounding)
C. Grounded conductor
D. Grounding electrode
3. Grounded conductors ______ are permitted to be identified either in the same manner as that required for conductors 6 AWG and smaller or, at the time of installation, by a distinctive white or gray marking at the terminations.
A. 4 AWG or larger
B. 12 AWG or larger
C. of aluminum and smaller
D. of copper and smaller
4. A 480-volt (V), three-phase, 3-wire, delta-connected system is always required to be grounded.
5. Where 30V alternating current (AC) systems are installed outdoors as overhead conductors, they ______ be grounded.
A. are not required to
B. are required to
C. shall be permitted to
D. shall not
6. Which of the following conductors is not present when installing an ungrounded system?
A. Equipment grounding conductor
B. Grounded conductor
C. Grounding electrode conductor
D. Ungrounded conductors
7. Where a system can be grounded so the maximum voltage to ground from any system ungrounded conductor does not exceed 240V, the system must be grounded.
8. The phase-to-ground voltage of a high leg in a 240/120V, three-phase, 4-wire, delta-connected system is ______.
9. Separately derived systems supplied by transformers having a primary voltage rating of less than 1,000V are not required to be grounded if all but which of the following conditions is met?
A. Continuity of control power is required.
B. Continuity of line power is required.
C. Qualified persons service this installation.
D. This system is used for control circuits only.
10. Where a transformer secondary is 30V AC and the primary is supplied by an ungrounded source, the secondary must be grounded.