Which option best explains why ribbed metal conduit might be used for wiring near a refrigeration system?

• A. It provides flexibility and accounts for vibration
• B. It improves electrical insulation
• C. It reduces electromagnetic interference
• D. It increases rigidity to prevent movement

Answer: (A)

Vibration and movement from refrigeration equipment mean you want wiring protection that can flex without stressing the wires. Ribbed metal conduit is designed to be flexible, so it can absorb side-to-side movement and the expansion and contraction from temperature changes without kink­ing or pulling on the conductors. This helps prevent damage to the wires and connections in a noisy, vibrating environment while still giving solid mechanical protection and a grounded path. Insulation isn’t the main job of the conduit, and while metal raceways can offer some shielding, that isn’t the primary reason to choose ribbed conduit near a refrigeration system. Increasing rigidity would defeat the purpose, since the goal is to accommodate movement rather than oppose it.