Some key general requirements in the National Electrical Code (NEC) address minimum working spaces around equipment, equipment markings and underground conduit installation depths. The authority having jurisdiction (AHJ) has significant interpretation and approval responsibilities. The NEC establishes minimum requirements.
Created by: Michael Johnston
1. According to the NEC, which of the following has the responsibility for interpreting the rules of the NEC and granting special permission?
A. Electrical engineer
D. Property owner
2. The minimum width of the required working space directly in front of a panelboard shall not be less than 30 inches, and this width does not have to be centered on the equipment.
3. Reconditioned equipment is required to be marked with the ________ by which the organization responsible for the reconditioning can be identified, along with the date of the reconditioning.
C. Other descriptive marking
D. Any of the above
4. In all cases, the working space about electrical equipment shall permit at least a ________-degree opening of hinged doors or panels.
5. What is the minimum working space required in front of a switchgear lineup if the applied voltage is 12,470 volts and there is a grounded surface in front of the switchgear?
A. 3 feet
B. 4 feet
C. 5 feet
D. 6 feet
6. What is the largest size copper grounding electrode conductor required for a direct current system if the grounding electrode is a concrete-encased electrode?
A. 6 AWG
B. 4 AWG
C. 2 AWG
D. 1/0 AWG
7. What is the minimum burial depth required for rigid metal conduit installed under a parking lot?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
8. North American Standard Pipe Taper (NPT) threaded entries into explosion-proof equipment shall be made up with not less than ________ threads fully engaged.
9. For a motor with a service factor of 1.15, a separate overload protective device shall not exceed ________ of the motor nameplate current rating.
10. Where underground conduits enter the bottom of a switchboard, they shall not rise more than ________ above the bottom of the enclosure.
A. 3 inches
B. 6 inches
C. 8 inches
D. 12 inches