1. See air duct.
2. In electric systems, a metallic or nonmetallic tube, (usually circular, oval, rectangular, or octagonal) for housing wires or cables; may be underground or embedded in concrete floor slabs.
1. See air duct.
2. In electric systems, a metallic or nonmetallic tube, (usually circular, oval, rectangular, or octagonal) for housing wires or cables; may be underground or embedded in concrete floor slabs.