TN LLE Raceway and Box Fill

Question 1

Per NEC Chapter 9, Table 1, what is the maximum conduit fill percentage for one conductor installed in a raceway?

Accepted Answer

53%

Answer

NEC Chapter 9, Table 1 permits 53% conduit fill when only one conductor is installed in a raceway.

Question 2

What is the minimum depth of a 4-inch square metal box commonly used at junction points?

Accepted Answer

2-1/8 inches

Answer

A standard 4-inch square (4S) box commonly used at junction points is 2-1/8 inches deep, providing 30.3 cubic inches of volume.

Question 3

Per NEC 314.28(A)(1), what is the minimum length of a pull box for a straight pull with 2-inch conduit?

Accepted Answer

16 inches

Answer

For a straight pull, NEC 314.28(A)(1) requires the box length to be at least 8 times the trade size of the largest raceway. 8 x 2 = 16 inches.

Question 4

Per NEC 314.16(B)(5), how many volume allowances does a single-gang yoke or strap with a device (switch or receptacle) count as?

Accepted Answer

Two volume allowances

Answer

NEC 314.16(B)(5) counts each device or yoke/strap as two volume allowances of the largest conductor connected to the device.

Question 5

What is the maximum number of quarter bends (90 degrees) permitted between pull points in a conduit run per NEC 344.26?

Accepted Answer

Four (360 degrees total)

Answer

NEC 344.26 limits bends between pull points to a total of 360 degrees, equivalent to four quarter bends.

TN LLE - Tennessee Limited Licensed Electrician Practice Test