Conduit Bending and Installation Flashcards

When bending a back-to-back (U-bend) in conduit, the second bend must be placed so that:

Answer: The two 90-degree bends face each other and the legs are parallel

A back-to-back bend creates a U-shape with two 90-degree bends facing each other, resulting in two parallel vertical legs.

According to the NEC, what is the maximum spacing for EMT conduit supports when run horizontally?

Answer: 10 feet

NEC 358.30 requires EMT to be supported at intervals not exceeding 10 feet for horizontal runs.

What is the primary purpose of a conduit expansion coupling?

Answer: To accommodate thermal expansion and contraction in long runs

Expansion couplings allow conduit to move axially as it expands and contracts with temperature changes, preventing buckling or stress.

When pulling wire through a conduit that has multiple bends, which technique reduces friction?

Answer: Using wire pulling lubricant (wire lube)

Wire pulling lubricant significantly reduces friction between conductors and the conduit wall, especially through bends.

Which conduit type is NOT permitted for direct burial without concrete encasement?

Answer: EMT

EMT is not listed for direct burial because its thin walls provide insufficient protection against soil corrosion and physical damage.

When bending conduit for a four-bend saddle, the center two bends should each be:

Answer: Half the angle of the outer bends

In a four-bend saddle, the outer bends are larger and the inner bends are half the outer angle, creating a symmetrical profile over the obstruction.

What is the NEC requirement for conduit installed in a wet location regarding fittings?

Answer: Fittings must be listed for wet locations

NEC 314.15 and conduit-specific articles require that fittings in wet locations be listed and identified for use in wet locations.