By Linda Sturdivant on January 24 2018 22:13:59
Cables for industrial, commercial and apartment buildings may contain many insulated conductors in an overall jacket, with helical tape steel or aluminium armour, or steel wire armour, and perhaps as well an overall PVC or lead jacket for protection from moisture and physical damage. Cables intended for very flexible service or in marine applications may be protected by woven bronze wires. Power or communications cables (e.g., computer networking) that are routed in or through air-handling spaces (plenums) of office buildings are required under the model building code to be either encased in metal conduit, or rated for low flame and smoke production.
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.
Rubber-like synthetic polymer insulation is used in industrial cables and power cables installed underground because of its superior moisture resistance.
Some components and symbols of wiring diagram are: Capacitor, used to store electric charge. Toggle Switch, stops the flow of current when open. Push Button Switch, momentarily allows current flow when button is pushed in, breaks current when released. Battery, stores electric charge and generates a constant voltage .Resistor, restricts current flow. Ground wire, used for protection. Circuit breaker, used to protect a circuit from an overload of current. Inductor, a coil that generates a magnetic field. Antenna, transmits and receives radio waves. Surge protector, used to protect a circuit from a spike in voltage. Lamp, generates light when current flows through. Diode, allows current to flow in one direction indicated by an arrowhead or triangle on the wire. Microphone, converts sound into electrical signal. Electrical motor. Transformer, changes AC voltage from high to low or vice versa. Headphone. Thermostat. Electrical outlet. Junction box.