First Semester final review
High Density Polyethylene conduit larger than ___ shall not be used.
6 Inch
Where a branch circuit is protected with a fused safety switch, the ___ determines the rating of the branch circuit.
ampere rating of the fuses
When ___ touch together, this is a ground fault.
an ungrounded circuit conductor and the metal conduit
The feeder neutral load is the maximum unbalance between ___.
any one of the ungrounded conductors and the grounded conductor
Which of these panelboard installations requires a minimum of 900 mm (3 ft) working clearance in front of the panelboard? This is a Condition 2 installation.
120/208-volt, 3Ø, 4-wire
Tap conductors for household cooking equipment not exceeding a 50-ampere branch circuit shall have an ampacity of not less than ___ amperes.
20
A 3/0 AWG conductor that is connected to a circuit breaker in a 120/240-volt, 3-ph, 4-wire panelboard can carry ___ amps of current inside the panel.
200
Where the opening to an outlet, junction, or switch point is less than 8 inches in any dimension, each conductor shall be long enough to extend at least ___ inches outside the opening of the enclosure.
3
Which of the boxes shown in Figure 107.31 can be "ganged" together to form a 3-gang box?
3
The minimum working clearance at Point X in Figure 201.15 is ___ feet. The panel is 120/240-volt, 3Ø, 4W.
3.5
Which of the following conductors is the smallest size permitted for a feeder where a 200-Amp breaker protects the feeder? The feeder originates in the 120/208-volt, 3-ph, 4-wire service panel in a home.
3/0
Refer to Figure 208.51. The minimum CALCULATED dimension for "width" is ___ inches. All conductors enter the right size of the pull box and exit the bottom.
31.5
Calculating and providing the proper volume of a box is not always enough. Section ___ of the NEC® states outlet and device boxes shall be deep enough so that conductors will not be damaged when installing wiring devices or equipment.
314.24
An 8" x 8" x 5' gutter is shown in Figure 208.63. The maximum number of 4/0 AWG THWN/THHN conductors that can be installed in the gutter is ___.
39
The maximum number of 4/0 AWG THHN/THWN conductors that can be installed in an 8" x 8" wireway (a section is shown in Figure 208.61) is ___.
39
Refer to Figure 205.14. Load 1 is supplied from a 150-A circuit breaker with 1 AWG conductors. Load 2 is supplied from a 300-Amp breaker with 4/0 AWG conductors. Both loads are 3-ph, 3-wire. Where only one grounding conductor is installed in the conduit between the panel and the pull box, its minimum size is ___ AWG.
4
Refer to Figure 204.7. The smallest size wire permitted for the tap conductors between Pull Box 2 and FD #1 (Fused Disconnect for Load #1) is ___ AWG. A 175-Amp breaker is installed in the panel and 4/0 AWG conductors are installed between the breaker and Pull Box 2. The distance between Pull Box 2 and FD #1 is 21 feet. The nameplate on Load #1 indicates that it will draw 43 amps. Don't forget that the switches have 75ºC lugs so you will select your wire from the 75ºC column.
6
Conductors that are enclosed in Schedule 80 PVC ___. a.are protected from physical damage b.are capable of being removed c.both a or b d.neither a nor b
Both A and B
Where a 6' length of Type MC cable is used in Figure 208.4, support(s) ___ can be omitted.
#1, #2, and #3
Refer to Figure 210.18. The grounded conductor between the MLO panel and the source of the power can carry current during ___.I. normal operation II. a ground-fault III. a short circuit
1 & 2 & 3
The ___, or other descriptive marking by which the organization responsible for the product may be identified, shall be placed on all electric equipment. I. trademark II. cost III. manufacturer's name
1 and 3
When a receptacle is located ___, it is required to be GFCI protected. I. above the kitchen countertop and within 6 feet of a sink at a restaurant II. in a bathroom adjacent to a basin in a restaurant III. outside on the exterior front wall of an elementary school
1,2,3
A unit load of ___ volt-amperes per square foot shall be used when calculating the lighting load of a restaurant.
1.5
No conductor larger than ___ AWG shall be installed in a cellular concrete floor raceway without special permission.
1/0
Which of the following THHN/THWN copper conductors is the smallest size permitted for a feeder where a 150-A breaker protects the feeder? The feeder originates in the 120/208-volt, 3-ph, 4-wire service panel in a home.
1/0
Where cables assemblies with nonmetallic sheathes are used, the seath shall extend not less than ___ inside the box and beyond any cable clamp.
1/4
Refer to Figure 203.4. This 480/277-volt, 3Ø, 4-wire service supplies an attorney's office. The minimum clearance at is ___. The overhead conductors are quadruplex cable and this area is accessible to automobiles but not trucks.
12
The minimum clearance above finished grade for overhead service conductors is ___ feet. The service is 120/240-volt, 3-ph, 4-wire. The span is over a sidewalk. The service drop uses quadruplex.
12
What is the ampacity of a 1/0 TW copper conductor?
125 Amps
At 180 VA per outlet, how many outlets can be installed on a 20-ampere circuit (120 volt) if the circuit loading is to remain within its ratings?
13
In Informative Annex D, Example D1(a), one-family dwelling, what is the calculated load for neutral?
14,550 VA / 240 V = 61 A
When the corrected ampacity of a 10 AWG copper conductor is 12.86 amps, the maximum size circuit breaker permitted to protect the conductors is ___.
15
Type AC cable shall be permitted to be unsupported where the cable is not more than ___ feet in length at terminals where flexibility is necessary.
2
What is the minimum trade size EMT permitted to be installed between two junction boxes that are 5 inches apart? The EMT will contain thirty-four 8 AWG, twenty 12 AWG, nine 6 AWG, and one 10 AWG THHN/THWN copper conductors.
2
What is the minimum trade size RMC permitted to be installed between two panelboards that are 5 inches apart? The RMC will contain four 4/0 AWG conductors and one 4 AWG ground. All conductors are THHN/THWN copper.
2
Refer to Figure 208.36. Which industrial cover/box combination will NOT violate the NEC®? All the conductors are 12 AWG. I. 4 x 11/2 square with 5.0 in3 industrial cover II. 411/16 x 11/4 square box with a 4.2 in3 industrial cover III. 4 x 21/8 square box with a 3.6 in3 industrial cover
2 and 3
Guest suites of hotels with permanent cooking provisions shall be required to have AFCI protection for the bedrooms according to ___ in the NEC®.
210.12(C)
Refer to Figure 201.15. The minimum working clearance at Point Z is ___ feet. The panel is 120/240-volt, 1Ø, 3W.
3
If the window is openable, the minimum clearance at C in Figure 203.6 is ___.
3 Feet
Refer to Figure 203.7. The minimum clearance at B is ___.
3 Feet
Refer to Figure 201.20.. The wall opposite the 120/208-volt panelboard is sheetrock. The minimum clearance from the panelboard to the opposite wall is ___ inches.
36
Refer to Figure 201.21. The minimum clearance from the 120/208-volt panelboard to the opposite wall is ___ inches. The wall opposite the panelboard is made of CMUs (cement blocks).
36
One receptacle is to be installed on a dedicated (individual) branch circuit. A receptacle rated at ___ amps could be used where the circuit is connected to a 40-A circuit breaker. I. 40 II. 50
40 & 50
The cross-sectional area of a 4 AWG BARE copper conductor is ___ cmils.
41740
Where two #18, three #16, two #14, three #12, two #10, three #8, and two #6 conductors are contained in a box, ___ cubic inches will be occupied in the box by these conductors.
43.00
A flexible cord connection is made directly to the load end terminals of a busway plug-in device. The maximum length of this cord to a tension take-up device is ___ feet.
6
A flush-mounted well light is located in the corner of a sidewalk at a house as shown in Figure 121.211. The sidewalk is 3" thick and Schedule 40 PVC will be installed for the power. This 20-amp, 120-volt circuit is GFCI protected. In inches, what is the minimum depth from the top of the conduit to the top of the sidewalk?
6
Where buildings exceed 3 stories or 50 feet in height, overhead lines shall be arranged, where practicable, so that a clear space (or zone) of at least ___ feet wide will be left either adjacent to the buildings or beginning not over 8 feet from them to facilitate the raising of ladders when necessary for fire fighting.
6
MC cable is used to connect a 2 x 4 lay-in fluorescent luminaire to a "home run" box as shown above in Figure 208.2. The length of the cable between the box and the luminaire is 26 feet. The maximum distance between the luminaire and support #2 is ___.
6 feet
Refer to Figure 201.21. The bottom of the 120/208-volt panel is at 34" AFF. The ceiling height can be no less than ___ AFF for this installation.
6'-10"
Measured from the point in the box where the conductors emerge from the conduit in the back of the junction box, shown in Figure 207.13, the minimum length of the conductors is ___". The junction box has a depth (d) of 4" and is 6" wide by 6" high.
7
In a dwelling, it shall be permissible to apply a demand factor of ___ percent to the nameplate rating load of four or more appliances fastened in place.
75
A bare ___ can be used as an equipment grounding conductor. I. busbar II. wire
Both
A 3-pole, 250-volt safety switch can be used as the disconnecting means for ___ motor circuit. a.a 2-wire, 120-volt, 1-phase b.a 2-wire, 208-volt, 1-phase c.a 3-wire, 208-volt, 3-phase 2020 NEC: 110.4 d.a 3-wire, 240-volt, 3-phase e.any of these
Any of these
Loads computed for dwelling unit ___ circuits shall not be permitted to be included with the general lighting load and subjected to the demand factors permitted in Table 220.42 for the general lighting load.
Appliance
The conductors and equipment required or permitted by this Code shall be acceptable only if ___.
Approved
Generally, circuit breakers ___ permitted to be connected to a neutral conductor.
Are not
Two 20-ampere small appliance circuits ___ supply more than one kitchen of a dwelling.
Cannot
When doing voltage-drop calculations, where is the cross-sectional area in circular mils located?
Chapter 9, Table 8
A unit of an electrical system, other than a conductor, that carries or controls electric energy as its principal function is referred to as a(n) ___.
Device
Refer to Figure 210.7, shown above. The conductors between Panel A1-1 and the switch are ___ conductors.
Feeder
Shown above is a 42 Circuit Panelboard. Where connected to breaker 14, a conductor is permitted by the NEC® to be ___ in color. This is a 120/208-volt, 3Ø, 4-wire panel. I. black II. purple III. orange
I or II or III
4 AWG conductors can be spliced inside an LB type conduit body using ___. I. crimp connectors II. screw-type splice connectors III. wire nuts
I or II or III
A branch circuit conductor is connected to breaker 21 in a 120/208-volt, 3Ø, 4-wire panel. The NEC® permits this wire to be ___ in color. A 42-circuit panelboard is shown above. I. black II. purple III. orange
I or II or III
Figure 201.71 shows the plan view of a room in a private club. A receptacle ___ required to be installed in the 18" wall space in the NW corner of the plan.
Is Not
Using a wire nut, a neutral that enters a box is connected to another neutral that exits the box. A pigtail is also connected under the wire nut and goes to a receptacle in the box. This pigtail ___ counted in the box fill calculation per 314.16(B)(1).
Is Not
A gas water heater is to be installed in the attic of a home to supply hot water for bathing, clothes washing, dish washing, etc. Which of the following are required to be installed in the attic near the water heater? I. a convenience receptacle II. a luminaire
Luminaire
You need to get power to a 208-volt load. Your available power is from a 120/240-volt, 3Ø, 4-wire panelboard. Is it permitted for you to run a branch circuit from the neutral bar and a 1-pole circuit breaker installed in breaker space #4? The CB has a 120-volt rating.
No
Rigid Metal Conduit (RMC) is generally made of galvanized steel or aluminum. Aluminum is considered to be a ___ metal.
Nonferrous
Where it is unlikely that two dissimilar loads will be in use simultaneously, it shall be permissible to ___ of the two in computing the total load of a feeder.
Omit the smaller
Where raceways are exposed to widely different temperatures, they shall be ___.
Sealed
Raceways on exterior surfaces of buildings shall be arranged to drain and shall be ___ for use in wet locations.
Suitable
Refer to Figure 204.6. The 8 AWG conductors in Conduit I are ___ conductors.
Tap
Refer to Figure 207.8, shown above. The conductors from Conduit X are permitted to occupy the junction box with the conductors from Conduit Z.
True
___ equipment is constructed so that water (in the form of moisture) will not enter it.
Watertight
Refer to Figure 108.014. This kitchen is in a house. Does the NEC® permit receptacle 11 to be connected to one of the 20-amp small-appliance branch circuits?
Yes
Wiring methods permitted in ducts or plenums specifically fabricated to transport environmental air include ___.
electrical metallic tubing
Informational Notes ( I-Notes ) in the National Electrical Code® are ___.
explanatory information (not mandatory)
The scope of Article 250 covers all of the following topics, except for ___.
grounding requirements for surge protection
The "hot" conductor of a circuit is referred to as the ___ conductor in the NEC®.
ungrounded
