Properly Securing Wiring
All Answers relate to NFPA 70, 2017 Edition
1. EMT shall not be permitted to be used as an equipment grounding conductor.
A. True
B. False
2. Conductors in vertical raceways shall be supported if the vertical rise exceeds the values in ________________.
A. Figure 317(B)
B. Table 300.19(A)
C. Exhibit 725.25
D. Section 725.25
3. What is the required amount of “free conductor,” measured from the point in the box where it emerges from a raceway?
A. 12 in.
B. 3 in.
C. 6 in.
D. An amount enough to work on the wires and still be able to push it back into the box without damage to the conductors.
300.14
4. Trade size one-inch Rigid Metal Conduit must be supported within ___________ of each outlet box, junction box, device box, cabinet, conduit body or other conduit termination.
A. 1 ft.
B. 6 in.
C.3 ft.
D. 5 ft.
344.30(A)
5. The maximum allowable size for LFNC is ______________.
A. Metric designator 12
B. Trade size 1.5
C. Metric designator 6
D. Trade Size 4
Feedback: 356.20 (B)
6. Unlike EMT, LFNC does not have a maximum number of bends.
A. True
B. False
7. The ends of EMT must be reamed or otherwise finished to remove rough edges after threading.
A. True
B. False
EMT is not to be threaded.
8. Installations employing a flush type cover or faceplate shall be done so that the front edge of a box, plaster ring, extension ring or listed extender will not be set back from the finished surface more than _____________ mm.
A. 1
B. 2
C. 4
D. 6
9. Non-combustible surfaces that are broken or incomplete around a box must be repaired so that there are no gaps greater than ______ at the edge of the box.
A. 1/4 in.
B. 3 mm
C. 7.5 mm
D. ½ in
10. A nonmetallic cable tray shall be permitted in corrosive areas and in areas requiring voltage isolation.
A. True
B. False
11. In underfloor raceways, the combined cross-sectional area of all conductors or cables shall not exceed __________ percent of the interior cross-sectional area of the raceway.
A. 53
B. 40
C. 25
D. 66
12. The minimum cover requirements for a nonmetallic raceway listed for direct burial without concrete encasement, in a one- and two-family dwelling driveway is ____________ inches.
A. 4
B. 6
C. 12
D. 18
300.5
What’s Wrong With This?
Here is a PoE camera mounted on a suspended ceiling. Can you identify a problem with this installation?
Click here to see the answer.
Answer to Can You Identify This?:
Although the photo made it challenging to recognize what might have been incorrect about this installation, there is actually nothing wrong here. Many readers might have answered that it was either screwed to the ceiling grid or was installed without the use of a bar and box assembly clipped to the gridwork. The camera is mounted to a UL-listed tee bar hanger. This device makes installation of the camera much easier and in compliance with regulations. The termination is an RJ45 completed inside the camera itself.
