WorksheetsNCCER Electrical 2 Module 7
Total questions: 22
Worksheet time: 11mins
Which of the following provides a curved surface for the cable to follow as it passes from the tray?
Swivel plate
Splice plate
Barrier plate
Dropout plate
A cable hanger elbow is used to ___.
Support piping
Divide a section of cable tray
Suspend cables in long vertical runs
Make vertical offsets
The most desirable method of exiting cable from a cable tray is ___.
Simply piping
From the end of the tray using a dropout plate
From the end of the tray without a dropout plate
Between rungs between without a dropout plate
What kind of mounting is often used in tunnels and other underground installations?
Direct rod mounting
Wall mounting
Trapeze mounting
Center-hung mounting
The method of supporting cable trays using threaded rods and hanger clamps is known as ___.
Wall mounting
Pipe rack mounting
Direct rod suspension
Center rail support
Which of the following occurs when the load applied causes the fibers on the tension side of the rung to stretch and permanently deform
Top-edge failure
Longitudinal failure
Transverse failure
Side-rail failure
The expected weight of an installed cable tray system is 200 pounds. Each support must be capable of carrying ___.
200lbs
250lbs
300lbs
350lbs
All multi conductor cables operating at or above 1,000v must be separated by a solid divider from cables operating under 1,000v, Except for ___.
Type UF
Type USE
Type MC
Type NM
Cable tray in a corrosive location is most often constructed of _____.
Nonmetallic material
Steel
Aluminum
Copper
Symbols used to show cable tray systems on working drawings are explained in the ___.
Detail drawings
Isometric
NEC
Legend
Which of the following is an NEC requirement for grounding and bonding cable tray installation?
Cable trays may not be as an equipment grounding conductor.
Nonmetallic cable trays must be bonded with flexible bonding jumpers.
Aluminum trays may not be used as equipment grounding conductors.
Cable tray sections and fittings must be bonded.
Conductors size 4/0 and larger in cable tray must be _____.
Installed in multiple layers
Tightly bundled
Spaced one cable diameter apart
Installed in single layer
Given a cable tray that is available in standard width of 6,12,18,24 and 36 what is the minimum width of a 3-inch-deep cable tray used for the following cables they are all 4/0 or larger; two 1.75-inch cables and four 2.5-inch diameter cables?
12 inches
18 inches
24 inches
36 inches
Which of the following statements is True regarding cable splices regarding cable trays?
Splices must be insulated using NEC approved methods.
Splices must be insulated where they are inaccessible.
Splices are never permitted in cable tray.
Splices should be left unsecured to allow for expansion and contraction.
Which of the following is True requiring ampacity adjustments of conductors in cable tray?
Only an uncovered tray requires ampacity adjustments.
Conductors in cable tray use the same ampacity tables as other conductors.
Conductors in a triangular configuration are exempt from free airspace requirements.
Systems carrying 2,000V and above are not subject to derating per the NEC
A 15-degree change in cable tray elevation is most
likely to require the use of _____.
horizontal adjustment splice plates
vertical adjustment splice places
an elbow
a riser
Light-duty applications such as telephone system
wiring is most likely to be run in _____.
monorail cable tray
pipe rack cable tray
wall-mounted cable tray
trapeze-mounted cable tray
The expected weight of an installed cable tray
system (including cable) is 400 lbs. Each support
must be able to carry _____.
300 lbs
400 lbs
500 lbs
800 lbs
When inspecting a long expanse of cable tray, you
discover that the tray is buckling. This is a type of
_____.
transverse failure
rung failure
side rail failure
splice failure
Cable tray must be bonded in accordance with
_____.
NEC Section 250.96
NEC Section 300.96
NEC Section 300.21
NEC Section 392.60
A cable tray contains eight 4/0 cables, and each
cable is 1.5" in diameter. The minimum width of the
cable tray is _____.
6"
8"
10"
12"
Which of the following is least likely to result in
ampacity derating of conductors in cable tray?
Number of cables
Tight cable configuration
Covered tray
Open tray
