CEA Wiring Methods and Materials 2

Question 1

What is the maximum number of 90-degree bends allowed in a single run of conduit between pull points according to the NEC?

Accepted Answer

Four 90-degree bends

Answer

NEC 358.26 limits conduit runs to a maximum of four quarter bends (360 degrees total) between pull points.

Question 2

Which wiring method is specifically listed for use in wet locations and is identified by a 'W' rating?

Accepted Answer

TW

Answer

TW conductors have a 'W' suffix indicating they are rated for wet locations, with a 60°C temperature rating.

Question 3

When installing flexible metal conduit (FMC), what is the minimum trade size permitted for general use?

Accepted Answer

1/2 inch

Answer

NEC 348.20 permits 3/8-inch FMC only in limited applications; 1/2-inch is the minimum for general use.

Question 4

Rigid PVC conduit (Schedule 40) must be supported at intervals not exceeding how many feet for trade sizes 1/2 to 1 inch?

Accepted Answer

3 feet

Answer

NEC 352.30 requires Schedule 40 PVC conduit 1/2 to 1 inch to be supported every 3 feet.

Question 5

Which conductor insulation type is rated for use in both wet and dry locations at 90°C?

Accepted Answer

THWN-2

Answer

THWN-2 is rated 90°C in both wet and dry locations, making it one of the most versatile insulation types.

(CEA) Certified Electrical Apprentice Practice Test