Basic Electrical Installation Work

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Definition An UPS essentially battery supply electronically modified provide a clean and secure a. An UPS protect small network of, say, six PCs physically about the size one hard drive and usually placed under the side an operator’s desk.Electrical installations and wiring systems 331 The UPS plugged into the mains supply and the computer systems are plugged into the UPS. Fibre-optic cables are also immune electrical noise when run parallel mains cables and, therefore, the present rules segrega- tion and screening may change the future. The light pulses stay within the fibre-optic cable because sci- entific principle known ‘total internal refraction’ which means that the laser light bounces down the cable and when strikes the outer wall is always deflected inwards and, therefore, does not escape out the cable, as shown Fig. The energy transferred down the cable digital pulses laser light as against current flowing down copper conductor electrical installation terms. The energy transferred down the cable digital pulses laser light as against current flowing down cop- per conductor electrical installation terms. Laser light pulses Optical fibre cable FIGURE 14. Optical fibre cables are communication cables made from optical-quality plastic, the same material from which spectacle lenses are manufactured. Fibre-optic systems dramat- ically reduce the number cables required for control and communica- tions systems, and this will turn reduce the physical room required for these systems. Electricians intending isolate supplies for testing or modification should first check and then check again before they finally isolate the supply order avoid loss damage computer systems. It best dedicate ring radial circuit the UPS and either con- nect the computer equipment permanently use non-standard outlets to discourage the unauthorized use and overloading these special sup- plies by, for example, kettles the cleaner’s vaccum. Optical fibre cables The introduction fibre-optic cable systems and digital transmissions will undoubtedly affect future cabling arrangements and the work the elec- trician. Networks based the digital technology currently being used so successfully the telecommunications industry are very likely become the long-term standard for computer systems. Intrinsic safety described Chapter under the heading Hazardous Area Installations. Finally, remember that most premises these days contain some computer equipment and systems.c.46. There spark risk the cable accidentally cut and, therefore, such circuits are intrinsically safe. Definition Optical fibre cables are communica- tion cables made from optical-quality plastic, the same material from which spectacle lenses are manufactured. supply.46 Digital pulses laser light down optical fibre cable. . 14. The UPS is plugged into the mains supply and the computer systems are plugged into the UPS