By Diane Oneil on February 10 2018 05:32:25
Cables usually are secured with special fittings where they enter electrical apparatus; this may be a simple screw clamp for jacketed cables in a dry location, or a polymer-gasketed cable connector that mechanically engages the armour of an armoured cable and provides a water-resistant connection. Special cable fittings may be applied to prevent explosive gases from flowing in the interior of jacketed cables, where the cable passes through areas where flammable gases are present. To prevent loosening of the connections of individual conductors of a cable, cables must be supported near their entrance to devices and at regular intervals along their runs. In tall buildings, special designs are required to support the conductors of vertical runs of cable. Generally, only one cable per fitting is permitted, unless the fitting is rated or listed for multiple cables.
Generally, single conductor building wire in small sizes is solid wire, since the wiring is not required to be very flexible. Building wire conductors larger than 10 AWG (or about 6 mm²) are stranded for flexibility during installation, but are not sufficiently pliable to use as appliance cord.
Essential for pre-study works, the wiring diagram allows the cable list to be produced. If the wiring diagram is useful during the pre-study phase, it is also an important tool for the design of the installation functional scheme. Starting with the wiring diagram, the user can start producing his installation as a pre-study, and then launch his study during the installation cabling, allowing a reduced production time.
A schematic shows the plan and function for an electrical circuit, but is not concerned with the physical layout of the wires. Wiring diagrams show how the wires are connected and where they should located in the actual device, as well as the physical connections between all the components.