Electrical conduit is a protective tube or raceway that houses and protects electrical wires from physical damage, environmental exposure, and unauthorized contact. Common types include rigid metal conduit (RMC), intermediate metal conduit (IMC), and polyvinyl chloride (PVC) conduit. HVAC installations use conduit to route wiring between disconnect switches, control panels, and outdoor equipment.
Technical Details
Conduit diameter depends on the number and gauge of conductors contained within it. NEC Article 344 and 352 specify fill percentages: no more than 53% of conduit cross-section for three or more conductors. Rigid metal conduit provides superior protection in high-traffic areas and outdoor installations, while PVC conduit offers corrosion resistance in salt-air environments. Bending radius minimums range from 6 to 10 times conduit diameter depending on type.
Practical Significance in HVAC
Properly installed conduit extends equipment lifespan by shielding wires from UV radiation, moisture, and mechanical damage. Local electrical inspectors verify conduit sizing and installation before energizing HVAC systems. Flexible metal conduit (Greenfield) provides convenient routing around equipment, though it requires grounding per NEC standards.