Flexible Metal conduit (FMC) is used wherever good flexibility is required due to movement or vibration of equipment, or where bends and offsets would be difficult with rigid conduit.
To meet various physical or chemical requirements, flex is made of galvanized steel, aluminum, brass, or bronze.
The flexible metal conduit cannot be used in wet locations unless conductors are of the lead-covered type or of another type specially approved for the conditions.
The flexible metal conduit can be used for lighting fixture connections, above suspended ceilings.
Liquid-tight is another type of spiral flexible metal armor and an outer plastic jacket has been added, that plastic being both liquid-tight and sunlight resistant.
Liquid-tight carries no marking for wire size, insulation, or voltage rating because wires must be pulled as needed.
The difference between flexible metal conduit (FMC) and Liquid-tight flexible metal conduit is that PVC coated on LFMC.
Its use in residences is quite limited. It is generally used in short runs for wiring outdoor air conditioning equipment or for wiring disposals under kitchen sinks.
The sizes of liquid tight metal conduit must be electrical trade sizes ½ inch to 4 inches, inclusive.
Provides good protection from entry of water, Oil, dust, etc.
It is used in short runs for wiring outdoor air conditioning equipment or for wiring disposals under kitchen sinks. Its use in residence is quite limited.