By Susan Feldman on July 11 2017 09:36:31
In North American practice, an overhead cable from a transformer on a power pole to a residential electrical service usually consists of three twisted (triplexed) conductors, with one being a bare neutral conductor, with the other two being the insulated conductors for both of the two 180 degree out of phase 120 V line voltages normally supplied. The neutral conductor is often a supporting "messenger" steel wire, which is used to support the insulated Line conductors.
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.
Special cable constructions and termination techniques are required for cables installed in ships. Such assemblies are subjected to environmental and mechanical extremes. Therefore, in addition to electrical and fire safety concerns, such cables may also be required to be pressure-resistant where they penetrate a vessels bulkheads. They must also resist corrosion caused by salt water or salt spray, which is accomplished through the use of thicker, specially constructed jackets, and by tinning the individual wire stands.
The wiring diagram lets you define the different installation components and locations (cabinets, control panels, consoles, connection boxes, etc.) and gives you a synoptic, functional view of the installation. The terminal strips and cabling connections between locations can be defined at the beginning, during or at the end of the project design. The length of the pathways can also be defined by the user and thus serve as a default value, for all cables within the given pathway.