If a 11/4" EMT raceway containing three conductors is already filled to 20% of its allowable fill, what is the raceway’s remaining conduit fill cross-sectional area in square inches?

If a 11/4" EMT raceway containing three conductors is already filled to 20% of its allowable fill, what is the raceway’s remaining conduit fill cross-sectional area in square inches?

• A. 1.496
• B. 1.1968
• C. .2992
• D. .4784

Answer: (D)

Conduit fill is limited to a percentage of the raceway’s interior cross‑section. For EMT with three conductors, the allowable fill is 40% of the interior area. The problem uses the standard maximum fill value for an 11/4" EMT with three conductors as 0.598 square inches. If the raceway is already at 20% of that allowable amount, the used area is 0.2 × 0.598 = 0.1196 in^2. The space left for conductors is the remainder: 0.598 − 0.1196 = 0.4784 in^2. So the remaining conduit fill is 0.4784 square inches.

Conduit fill is limited to a percentage of the raceway’s interior cross‑section. For EMT with three conductors, the allowable fill is 40% of the interior area. The problem uses the standard maximum fill value for an 11/4" EMT with three conductors as 0.598 square inches. If the raceway is already at 20% of that allowable amount, the used area is 0.2 × 0.598 = 0.1196 in^2. The space left for conductors is the remainder: 0.598 − 0.1196 = 0.4784 in^2. So the remaining conduit fill is 0.4784 square inches.