Wireways and Raceways

If an auxiliary gutter contains splices and taps, the conductors, including the splices and taps shall not fill the gutter to more than __________ percent of it’s area.

75 % 366.44(A)

What is the minimum width ladder cable tray that may be used if it will contain twenty one (21) 250 kCMIL XHHW conductors.

9 inch .3904 x 21= 8.1984 square inches from

Table 5 Column one of Table 392.10(A) allows a 9

inch cable tray to contain 9.5 square inches of cables.

392.10(A)(2)

A unbroken length of surface nonmetallic raceway shall be permitted to pass transversely through dry walls provided ____________ is provided on both sides of the wall.

Access to the conductors 388.10(2)

Lighting busway shall be installed generally at least ______________ feet above the floor or working platform.

8 feet 368.12(E)

A metallic wireway is installed with a 3” conduit on one end and a 3” conduit on the other end. The wireway shall be used as a pull box for (4) 250 kCMIL THHN conductors. What is the minimum required length of this wireway?

24” 376.23(B) 314.28 3 X 8= 24

A nonmetallic extension shall be permitted to be run in any direction from an existing outlet as long as it is not within ___________ inches from the floor.

2 inches 382.15(A)

What is the minimum standard cross section dimensions required for an auxillary gutter if it is to contain the following conductors?

(15) 6 AWG THWN conductors (22) 8 AWG TW conductors (6) 2/0 AWG THHN conductors

(15) 6 AWG THWN .0507 x 15= .7605 (22) 8 AWG TW .0437 x 22= .9614 (6) 2/0 AWG THHN .2223 x 6= 6.8646Sum of the areas = 8.5865 square inches divided

by .20 (20 percent)= 42.9325 square inchesThe square root of 42.9325 is 6.5523 inches

An 8” by 8” minimum gutter will be required as there are no 7” standard sized gutters.

366.22(A)

The maximum sized conductor that can be installed in a cellular concrete floor raceway is __________________.

1/0 AWG 372.10

What is the minimum standard size Strut-Type Channel raceway that may be used if it is contain (9) 10 AWG THHN conductors? The raceway utilizes internal joiners.

10 AWG THHN .0211 x 9= .1899 Table 384.22 using the 25% Area column

allows up to .222 square inches of fill in a 1 5/8” by 13/16” strut-type channel.

384.22

Assuming all other requirements are met what is the minimum allowable area of a steel cable tray used to house conductors for a circuit protected by a 600 A dual element time delay fuse?

1.50 square inches Table 392.7(B)

What is the ampacity of a 500 KCMIL THHN conductor that is installed in a ladder cable tray in accordance with 392.10 if the cable tray is covered for a distance of 12” with a solid, unventilated cover?

700 amperes x .60= 420 amperes

392.11(B)(2) and T 310.17

How many markers are required to be installed in cellular metal floor raceways for locating cells in the future?

A suitable number

374.8