Single-phase and Three-phase Distribution Systems 287
foot lengths, which must be threaded for joining the pieces together. The
conduit is secured to metal wiring boxes by locknuts and bushings. It is
bulky to handle and takes a long time to install.Electrical Metallic Tubing (EMT)
EMT, or thinwall conduit, is somewhat like rigid conduit, except that
it can be bent with a special conduit-bending tool. EMT is easier to install
than rigid conduit, since no threading is required. It also comes in 10-foot
lengths. EMT is installed by using compression couplings to connect the
conduit to metal wiring boxes. Interior electrical wiring systems use EMT
extensively, since it can be easily bent, can be connected together, and can
be connected to metal wiring boxes.