This module offers grounding in the supply and distribution in the electrical power supplies for industrial, commercial and domestic installations. The focus is on developing the necessary techniques for the successful design of low voltage power supply, distribution, and lighting in buildings. The aim of this module is to provide the students with knowledge and skills to design and supervise the installation of electrical supply and lighting systems in buildings.
The Physics of Light: Sources of light. The Spectrum, the wave nature of light; Refraction Index; Relative Spectral Sensitivity of the Eye. Specula, diffuse, spread and compound reflection of light. Luminous flux and intensity. Illuminance: the Inverse-square and Cosine Laws. Superposition. Luminance.
Photometric Data Polar curves, zone factors. light output ratios. Spacing to mounting height ratios. Utilisation Factors. Glare index. Luminaire classification methods.
Interior Lighting Design (a) Uniform Lighting Systems. Design objectives. Design criteria. CIBSE Guide for Interior Lighting Design. The Lumen Method of Lighting Design: Room Index; Utilisation Factor tables; Luminaire maintenance and the determination of Maintenance Factor; Room surface reflectance’s and the calculation of floor and ceiling cavity reflectance’s; Determination of horizontal, wall and ceiling illuminance; Luminaire spacing, general, localised and local luminaire arrangements. (b) Non-Uniform Lighting Systems. The point source: The use of polar curves; Illuminance curves and isolux diagrams; The Cone Diagram; The spacing of point sources; Applications
Emergency Lighting Escape lighting: Main objectives; Illuminance calculations methods and location of emergency luminaries for corridors, stairways, auditorium, large open plan areas etc; Response time and duration of emergency luminaries; Escape route signs; Glare; Equipment: Electrical systems; Types of luminaires and lamps. Standby lighting.
Lamps Light production: Incandescence, electrical discharge and phosphorescence. Main types: Incandescent; low and high pressure discharge plus associated control gear. Lamp and circuit efficacy; Colour rendering and colour appearance. Applications.
Luminaires Basic design requirements: Photometric classifications; Electric shock classification; Enclosure classification; Surface temperature classification; Classification for explosive zones.
Daylighting of Buildings The benefits and problems of daylighting. Sources of daylight: Direct sunlight; the Uniform Sky; the C.I.E. Standard Overcast Sky. Daylight factor: Recommended values. Predicting the amount of daylight for side-lit and roof-lit interiors; Sky Component; Externally Reflected Component; Internally Reflected Component; Correction factors for windows, dirt and orientation. Approximate prediction of Average Daylight Factor; Predicting the quality of daylighting a side-lit room: The Limiting Depth; The No-Sky Line.
Electrical Power Electrical supplies to buildings; The national grid system, distribution voltages, forms of the supply arrangement, medium and low voltage intakes, ring main arrangements, final ring and radial circuit arrangements, accommodation requirements of intake rooms/substation rooms/transformer rooms, transformer arrangements, cooling and performance. Earthing arrangements.
IEE and ETCI Wiring Regulations 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 and discrimination. Electric shock protection, fibrillation, earthing and bonding, the functions of RCD device. Protection against indirect contact; Calculation of voltage losses in cables.
Cable 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, mould case circuit breakers, air circuit breakers; Performance characteristicscurrent / 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 board and distribution boards; Sub main system design and diversity; Final sub circuits; Lighting circuit design; Current loading and power circuits design. Distribution to motive power loads; Extensive worked examples.
Tariffs Metering arrangements; Different forms of tariff structure; Power Factor Correction.
Motors Motor principles; Induction motors; characteristics and winding arrangements; Torque speed characteristics; Frequency control. Motor protection; Characteristics and types of overload protection; co-ordination of protection; motor starting arrangements, direct, star delta and transformer start.
Final Control Elements Pneumatic and electrical actuators; Positioners valves and dampers. Air conditioning controls; Boiler and chiller controls.
Controller Mechanisms and Circuits Electronic controllers; Switching thermostats and humidistat's. Optimum start controllers; Thermostatic radiator valves
Closed-loop Negative Feedback Control Dynamic & Steady –state response of first order and second order systems. Performance specifications. Higher order systems and stability.
A variety of learning and teaching methods are employed to achieve the module learning outcomes. These include lectures, discussion, case study, problem-solving exercises, readings, project work, self-directed learning, and computer-based research.
| Module Content & Assessment | |
|---|---|
| Assessment Breakdown | % |
| Formal Examination | 60 |
| Other Assessment(s) | 40 |