Conduit Bending and Installation Flashcards

What is the minimum bend radius for 1-inch EMT conduit according to the NEC?

Answer: 6 inches

The NEC requires a minimum bend radius of 6 times the internal diameter for 1-inch EMT, which equals approximately 6 inches at the inside of the bend.

When making an offset bend in conduit, the two bends must be made in:

Answer: Opposite directions in the same plane

An offset consists of two equal bends made in opposite directions in the same plane, creating a parallel shift in the conduit run.

What tool is used to check that a conduit bend is a true 90 degrees?

Answer: Any of the above

A torpedo level, combination square, or speed square can all be used to verify a 90-degree bend is accurate.

What is the purpose of applying a 'gain' calculation when bending conduit stubs?

Answer: To account for the conduit shortening through the bend arc

Gain is the amount the conduit effectively shortens at the outside of a bend arc, and it must be subtracted from the mark-to-end measurement.

Which type of conduit bender is most appropriate for bending large-diameter rigid conduit (2 inches and above)?

Answer: Hydraulic bender

Hydraulic benders provide the force needed to bend large-diameter rigid conduit without kinking or flattening.

When installing conduit through a fire-rated wall, what is required at the penetration?

Answer: Fire-rated caulk or a listed firestop system

NEC 300.21 requires openings in fire-rated assemblies to be firestopped with listed materials to maintain the fire rating.

What is the maximum number of quarter-bend equivalents (360 degrees total) allowed between pull points in a conduit run?

Answer: Four 90-degree bends

NEC 358.26 (and similar sections) limits conduit runs to a maximum of 360 degrees of bends between pull points, equivalent to four 90-degree bends.