The aim of this module is to provide Building Services Engineers with an understanding of electrical services with regard to power applications and distribution systems.
Electrical Supplies to buildings: the national grid system, distribution voltages, forms of the supply arrangement, high voltage intakes, low voltage intakes, ring main arrangements and radial arrangements, accommodation requirements of intake rooms/sub station rooms/ transformer rooms; transformer arrangements, cooling arrangements, performance, intake earthing arrangements. ETCI / NSAI wiring rules: introduction to safety and protection, overcurrent protection, influence of ambient temperature, grouping and thermal insulation on maximum rated current, cable sizing procedure and examples; short circuit protection, fault calculations, discrimination; electric shock protection, effects of electric shock, earthing and bonding, the function of the RCD device; protection against indirect contact; calculation of voltage losses in cables. Cable management systems: types of cables, types of conductor, insulation and protection, cable support and housing systems, cables run in void spaces, current rating of cables. Protective equipment: fuses, miniature circuit breakers, moulded case circuit breakers, air circuit breakers, performance characteristics – current/time graphs and description of operation, fault energy I2 t, overload and short circuit operation, discrimination and circuit breakers, fault calculations. Wiring distribution: electrical distribution schematics, construction of main boards and distribution boards, sub-main system design and diversity , final sub circuits, lighting circuit design, circuit loading, power circuits design, distribution to motive power loads, extensive worked examples.
