Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
8 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
1. a trade size 3 schedule 40 PVC Raceway contains seven 1 RHW conductors without outer cover. How many 2 thw conductors may be installed in this Raceway with existing conductors? (a) 11 conductors (b) 15 conductors (c) 20 conductors (d) 25 conductors |
(a) 11 conductors |
Area conductor fill for a trade size 3, schedule 40 PVC (RNC) Raceway: 2.907 sq in. [ Chapter 9, Table 4, 40% column] Area 1 RHW without cover: 0.1901 sq in. [ Chapter 9, Table 5] Area of seven 1 RHW conductors: 0.1901 × 7 conductors = 1.3307 sq in. Spare space : 2.907 sq in. - 1.3307 sq in. = 1.5763 Quantity of 2 THW permitted in spare space: 1.5763 sq in./0.1333 = 11.80 conductors Note: the answer is 11 conductors. We only round up to the next size when all of the conductors are the same size ( total cross-sectional area including insulation) and the calculation results in a decimal 0.80 or greater. Sea chapter 9, Table 1, Note 7. |
|
|
2. What size wire weight is required for three 400 kcmil THHN, one 250 kcmil THHN, for 4 4/0 THHN conductors, and three 8 THHN conductors? (a) A 4 in. × 4 in. wireway (b) A 6 in. × 6 in. wireway (c) An 8 in. × 8 in. wireway (d) A 10 in. × 10 in. wireway |
(b) A 6 in. × 6 in. wireway |
Conductor area[ Chapter 9, Table 5]: 400 kcmil THHN = 0.5863 sq in. × 3 = 1.7589 sq in. 250 kcmil THHN = 0.3970 sq in. 4/0 THHN = 0.3237 × 4= 1.2950 sq in. 8 THHN = 0.0366 × 3= 0.1098 Total conductor area = 3.5607 sq in.
Conductor area × 5 = required wireway minimum area: 3.5607 sq in. × 5=17.80 sq in. The why your way must not be filled over 20%, or 1/5[376.22(A)]Conductor area × 5 = required wireway minimum area: 3.5607 sq in. × 5=17.80 sq in.A 6 in. × 6 in. wireway has a cross sectional area of 36 sq in. and will be large enough. A 6 in. × 6 in. wireway has a cross sectional area of 36 sq in. and will be large enough. |
|
|
3. Determine the minimum number of cubic inches required for two 10 AWG conductors passing through a box, four 14 AWG conductor spliced in the Box, two 12 AWG conductors terminating to a receptacle, and one 12 AWG equipment bonding jumper from the receptacle to the Box. (a) 15 cu in. (b) 20 cu in. (c) 21.75 cu in. (d) 22 cu in. |
(d) 22 cu in. |
2-10 AWG passing through 2-10AWG 1-1 yoke ( receptacle ) 2-11AWG 4-14 AWG spliced in the box 4-14AWG 2-12 AWG for terminating 2-12AWG 1-12 AWG bonding jumper 0-12AWG Total: two 10 AWG conductors, four 12 AWG conductors, and four 14 AWG conductors ( note: installation type doesn't matter for box fill calculations). Volume of the conductors: [ Table 314.16(B)] 10 AWG: 2.50 cu in. × 2 conductors 5 cu in. 12 AWG: 2.25 cu in. × 4 conductors 9 cu in. 14 AWG: 2 cu in. × 4 conductors 8 cu in. Total 22 cu in. |
|
|
4. When determining the number of conductors in a box that has one 14/3 W/G NM cable, one switch, and two internal cable clamps, the count will equal _______. (a) 6 conductors (b) 7 conductors (c) 8 conductors (d) 10 conductors |
(b) 7 conductors |
[314.16(B)] Volume of the conductors: 1-14/3 3-14AWG conductors 1-Ground 1-14AWG conductor 1-switch 2-14 AWG conductors 2- clamps 1-14 AWG conductor Totals Count 7-14 conductors |
|
5. The minimum horizontal dimension for the junction box shown in the diagram and▶Figure 5-83 is__________. (a) 18 in. (b) 20 in. (c) 21 in. (d) 24 in. |
(d) 24 in. |
[314.28(A)] Straight: Left to Right: 8 × 3 in. = 24 in. Right to Left: 8 × 3 in. = 24 in. Angle: Left to Right: (6 × 3 in.) + 2.50 in. + 2 = 22.50 in. Right to Left : (6 × 3 in.) + 2.50 in. = 20.50 in. |
|
6. The minimum vertical dimension for the junction box shown in ▶Figure 5-83 is ________. (a) 16 in. (b) 18 in. (c) 20 in. (d) 24 in. |
(a) 16 in. |
[314.28(A)] Straight: None possible Top to Bottom: Angle; None possible Bottom to Top: Angle; (6 × 2 in.) + 2 in. + 2 in. = 16 in. |
|
|
7. The minimum distance between the two trade size 2 race-ways that contain the same Conductor C, as illustrated in ▶Figure 5-83 is _______. (a) 12 in. (b) 18 in. (c) 24 in. (d) 30 in. |
(a) 12 in. |
[314.28(A)(2)] 6 × 2 in. = 12 in. |
|
|
8. If a trade size 3 raceway entry (250 kcmil) is in the wall opposite a removable cover, the distance from that wall to the cover must not be less than ______. (a) 4 in. (b) 4 1/2 in. (c) 5 in. (d) 6 in. |
(b) 4 1/2 in. |
[314.28(A)(2) Ex and Table 312.6(A)] |
