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Section 2 Installation
Frequently, FMC is used with EMT or rigid
conduit. It is substituted where bends are
needed. Instead of making complicated bends
and angles in EMT or rigid conduit, a section
of FMC can be inserted. There are special bush-
ings, locknuts, and couplings to connect FMC
to the other forms of conduit. There are also
length limits as stated in the NEC.
Liquidtight Flexible
Metal Conduit
Liquidtight fl exible metal conduit (LFMC)
is similar to FMC, but LFMC is covered with a
continuous plastic sheath. This system is easy
to install and can be used in most locations.
In residential installations, LFMC is typically
used to connect a central air conditioner unit
to a disconnect. See Figure 4-31. Its extreme
fl exibility makes LFMC an optimum choice
to connect machinery that is portable or may
vibrate during normal operation. LFMC is also
permitted as a service wiring method up to 6’
in length. Use of LFMC requires use of some
special fi ttings and connecting procedures.
Surface-Mount Raceways
Surface-mount raceway is an assembly of
two sections, a base and a cover, that is gener-
ally rectangular or a fl attened oval. Sections are
10′ long and range from 3/8″ to 3″ high and
Liquidtight Flexible Metal Conduit: Type LFMC — Article 350
Locations Allowed
Dry
Wet
Direct burial (where listed and marked)
Sizes
1/2″
through
4″
Maximum Mounting Distance
12″
4 1/2′
Figure 4-31. This air conditioner is connected to the disconnect with LFMC.