Drawing and diagrams. Block diagrams. This type of diagram provides
information about a sequence. What type of electrical information may be
presented in ...
Chapter 3: Storage and retrieval of technical information
Electrical installations Level 2 3.1 Indentifying sources of technical information
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Chapter 3: Storage and retrieval of technical information
Storage and retrieval of technical information • In which ways can technical information be stored? • What are the advantages of electronic filing compared to paper-based archives? • What are the disadvantages?
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Chapter 3: Storage and retrieval of technical information
Circulation of technical information • In which ways can technical information be sent? • What are the advantages of electronic circulation compared to paper-based archives? • What are the disadvantages?
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Chapter 3: Storage and retrieval of technical information
Drawing and diagrams In which ways can technical information be shown? • • • • • •
block diagrams circuit diagrams wiring diagrams schematic diagrams assembly drawings site plans
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Chapter 3: Storage and retrieval of technical information
Drawing and diagrams Block diagrams This type of diagram provides information about a sequence. What type of electrical information may be presented in this way?
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Chapter 3: Storage and retrieval of technical information
Drawing and diagrams Circuit diagrams These will show detail on how the circuit works, with component detail. In what types of situations would circuit diagrams be most useful?
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Chapter 3: Storage and retrieval of technical information
Drawing and diagrams Wiring diagrams In what way is this type of diagram different from a circuit one? In what type of situations would wiring diagrams be more useful than circuit diagrams?
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Chapter 3: Storage and retrieval of technical information
Drawing and diagrams Schematic diagrams These are used to demonstrate how a system works in sequence. In what way is this type of diagram different form a block diagram?
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Schematic diagrams don’t necessarily show connection details but how the process works. In electrical drawings, schematic diagrams are similar to block diagrams but show more detail. Ask the students if they can give an example of information that would be best represented by a schematic diagram. e.g: for showing how a large installation’s distribution system works.
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Chapter 3: Storage and retrieval of technical information
Drawing and diagrams Assembly drawings Can you give an example of information that would be best represented by a 3D drawing of this kind?
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These are usually 3D drawings showing how equipment can be put together.
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Chapter 3: Storage and retrieval of technical information
Drawing and diagrams Location drawings What do you think an ‘as fitted’ location drawing is? Can you explain what the scale of a location drawing is?
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These are 2D drawings showing a building layout. Ask the students if they can give an example of information that would be best represented by a 2D drawing of this kind. They give a bird’s eye view of a particular floor within a building. When building work is complete and drawings are made to show the finished building plan together with final locations of equipment, the drawing is called the ‘as fitted’ drawing.
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Chapter 3: Storage and retrieval of technical information
Drawing and diagrams Location drawings: scale If the scale of this drawing was 1:100 then the arrow representing a dimension of 5m would be 5cm long. Having an incorrect scale could be very costly. Why?
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All location drawings will have a scale. The scale indicates how large any particular dimension from the drawing is in reality. If the scale of this drawing was 1:100 then the arrow representing a dimension of 5m would be 5cm long. For example, if a drawing had a scale of 1:50, it would indicate that every 1mm measured from the drawing would equal 50mm in reality. The same could apply to centimetres or metres, providing you use the same unit from the drawing in reality. If the scale of this drawing was 1:100 then the arrowed line showing a dimension of 5m would actually measure, on the drawing, 5cm Tip: when working out a drawing scale, measure a single door. As most doors are just under 1 m wide, this will give you a good idea that you have the right scale. Having an incorrect scale could be very costly. Why?
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Chapter 3: Storage and retrieval of technical information
Drawing symbols What are the general symbols for the following items? • • • •
switch lighting outlet fluorescent luminaire socket
A
B
C
D
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BS 60617 is a comprehensive library of drawing symbols. These symbols should always be used to minimise confusion.
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