CGLI 2330 Certificate in Electrotechnical Technology Level 2 Installation Technology: Unit 205 – Installation (Buildings & Structures)
Unit 02 – Types, Components & Function of Electrical Installations
Types, Components & Function of Electrical Installations Unit Aims By the end of the unit participants should be able to:
State types of electrical installation, components and related functions a) Lighting - providing functional levels of illumination in buildings and structures b) Heating - providing space and water heating and heating of commercial and industrial applications c) Power - providing circuits to drive electrical equipment, systems and components d) Environmental control - providing circuits and components to control heat/air e) Emergency management systems - providing circuits to support lighting/power in the event of a failure in the primary system f) Security and alarm systems - providing access/intruder controls and fire alarms g) Closed Circuit TV, communication and data transmission systems – providing specialised cabling for communication systems (Syllabus Reference: 4.3.01)
Types, Components & Function of Electrical Installations There are man different types of electrical installations with most having components unique to them. In this section we will investigate some of the more common types of electrical installation along with their components and function. Lighting Installations Lighting circuits provide functional levels of illumination in buildings and structures. These functional levels of illumination will depend on the use of the building or structure. For example, a watchmakers’ workshop will require a high level of illumination if the work is to be carried out effectively and efficiently. On the other hand, a hotel lounge would generally have more subdued illumination levels to produce a more relaxing environment for guests.
Try This: In the following list, determine whether each example requires a high, medium or low level of illumination: Living room:
Bedroom:
Engineering workshop:
Clothes shop:
Jewellers:
Warehouse:
Office:
School classroom:
Public house
Restaurant eating area:
Restaurant kitchen:
Laboratory:
Street lighting:
Storage yard:
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Unit 02 Page 1
August 2011
CGLI 2330 Certificate in Electrotechnical Technology Level 2 Installation Technology: Unit 205 – Installation (Buildings & Structures)
Unit 02 – Types, Components & Function of Electrical Installations Components of Lighting Circuits: The components generally found in lighting circuits are as follows:
Protective device (fuse, circuit breaker)
Cables
Means of controlling the circuit (switch)
Means of converting electrical energy into light (luminaire).
Heating Installations Heating circuits provide space (that is, warming a room or area), water heating and heating for cooking operations as well as heating of commercial and industrial applications. Space heating sources include convection heaters, fan heaters, under-floor heating and oil-filled radiators. Water heating sources include immersion heaters, instantaneous water/shower heaters and electrode boilers. Cooking operations include filament elements, induction heating, halogen elements and microwave. Commercial and industrial heating include larger scale versions of domestic heating as well as specialist heating, e.g. induction heating in steel mills. Components of Heating Circuits: The components generally found in heating circuits are as follows:
Protective device (fuse, circuit breaker)
Cables
Means of controlling the circuit (switch)
Thermostat
(Sometimes) a timing device
Means of converting electrical energy into heat.
Power Installations These provide circuits to drive electrical equipment, systems and components. In its simplest form this is accomplished by use of a plug and socket wired into a socket circuit. In commercials and industrial systems it will provide power to machinery and equipment including electric motors. Components of Power Circuits: The components generally found in power circuits are as follows:
Protective device (fuse, circuit breaker)
Cables
Means of controlling the circuit (switch, starter)
(Sometimes) means of easily connecting/disconnecting equipment
Load.
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CGLI 2330 Certificate in Electrotechnical Technology Level 2 Installation Technology: Unit 205 – Installation (Buildings & Structures)
Unit 02 – Types, Components & Function of Electrical Installations Environmental Control These provide circuits and components that will be used to monitor and control the environmental conditions, i.e. heating and air condition. This includes devices that can measure temperature and humidity for example and, in some modern applications, detecting when the sun is shining through windows so that shades or blinds can be automatically brought into operation. Components of Environmental Control Circuits: The components generally found in environmental control circuits are as follows:
Protective device (fuse, circuit breaker) Cables Sensors (thermostat, humidity sensor, light sensor) Relays.
Emergency Management Systems These are circuits that support lighting and/or power in the event of a failure in the primary supply system. In its simplest form this includes back-up supplies for individual equipment, e.g. uninterruptible power supply (UPS) for an individual computer ranging right the way up to provide a complete back-up supply for a whole installation. Other typical examples include emergency & standby lighting and, very important, back-up supplies for hospitals. Components of Emergency Management Systems: The components generally found in emergency management systems are as follows:
Protective device (fuse, circuit breaker) Cables Batteries Charging equipment Prime mover generator Means to detect supply interruption/restoration.
Security and Alarm Systems These are circuits that provide access/intruder controls and fire alarms. Included in this are intruder detection systems, entry systems (card entry, code entry, manual systems) and fire detection, alerting and fire fighting systems. Components of Security and Alarm Systems: The components generally found in security and alarm systems are as follows:
Protective device (fuse, circuit breaker) Cables Detectors/sensors Batteries Charging equipment Alerting devices Entry equipment (key pad, card reader, intercom).
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Unit 02 Page 3
August 2011
CGLI 2330 Certificate in Electrotechnical Technology Level 2 Installation Technology: Unit 205 – Installation (Buildings & Structures)
Unit 02 – Types, Components & Function of Electrical Installations Closed Circuit TV, Communication and Data transmission systems These provide specialised cabling for communication systems. Because of the complex signals sent down these cables they need to be very special types. Components of Closed Circuit TV, Communication and Data transmission Systems: The components generally found in these systems are as follows:
Protective device (fuse, circuit breaker) Cables Fibre optic cables Connection and relay units Stabilised ‘clean’ power supplies.
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August 2011