Reference no: EM132349625

Electrical Systems Design

Aim: This unit provides the learner with the understanding of electrical systems design using design techniques and determining system requirements. It also provides learners with the understanding needed to plan work programmes and contractual implications of electrical design

Learning outcome

1. Understand how to prepare for the installation of wiring systems

1. Describe how to plan and implement:

a. work allocations

b. duties of operatives for whom they are responsible

c. coordination with other services and personnel.

2. identify relevant sources of information which will inform electrical work

3. describe the actions required to ensure that electrical work sites are correctly prepared in terms of Health and Safety considerations

4. state why it is important to check for any pre-existing damage to customer/client property prior to commencement of any work activity

5. explain how to check for any pre-existing damage to customer/client property:

a. Equipment and components

b. Building décor and floor finishes.

6. state the actions that should be taken if pre-existing damage to customer/client property is identified

7. specify methods for protecting the fabric and structure of the property before and during electrical work

2. Understand the applications of wiring systems

1. explain the constructional features, applications, advantages and limitations of electrical cables

2. explain the characteristics of containment, support and wiring systems used in electrical installations

3. determine the size of conduit and trunking as appropriate to the size and number of cables

4. describe the factors which affect the selection of wiring systems, associated equipment and enclosures.

5. Assess and select suitable wiring systems and equipment appropriate to the situation and use

3. Understand the practices and procedures for carrying out electrical work

2. state the procedures for selecting and safely using equipment for measuring and marking out for wiring systems, equipment and enclosures

3. state the criteria for selecting and safely using tools and equipment for fixing and installing wiring systems, associated equipment and enclosures

4. state the criteria for selecting and safely using fixing devices for wiring systems, associated equipment and enclosures

5. assess and specify the installation methods and procedures to ensure that in accordance with the installation specification and statutory and non-statutory  regulations:

a. wiring systems, enclosures, cables and components are securely fixed and installed

b. a wiring system’s mechanical integrity is maintained

c. no damage to the wiring system or its components has occurred

6. specify methods and techniques for restoring the building fabric

4. Understand the characteristics and applications of supply systems and consumer's equipment

1. explain the characteristics and applications of earthing arrangements

2. explain the characteristics and applications of supply systems

3. specify the arrangements for electrical installations and systems with regard to provision for

a. Isolation and switching

b. Overcurrent protection

c. Earth fault protection.

5. Understand earthing and protection

1. explain the purpose of earthing and protective conductors

2. identify extraneous and exposed conductive parts

3. describe the requirements and measures for protection against electric shock

4. state the maximum disconnection time for different types of circuit

5. explain the earth fault loop path and earth fault loop impedance

6. specify requirements and applications of functional earthing

7. select suitably sized protective conductors in accordance with BS 7671

6. Understand protection against overcurrent

1. identify types of and reasons for overcurrent

2. explain the operating principles, applications and limitations of protective devices

3. identify fault current capacities of devices

4. outline the need for discrimination between protective devices

7. Understand electrical systems and circuits

1. describe the characteristics of standard electrical circuits

2. outline the key characteristics of particular electrical systems and circuits and the applications of these circuits and systems

8. Understand the electrical design procedure

1. state the purpose of diversity factors

2. select suitable current using equipment giving consideration to energy efficiency and relevant codes of practice for sustainability

3. determine the maximum demand (of an installation) after the application of diversity

4. determine the design current

5. select a suitably rated protective device

6. establish the installation method reference

7. determine appropriate rating factors

8. determine the minimum cross-sectional area of live conductors taking into consideration current carrying capacity and voltage drop

9. establish if the voltage drop is acceptable

10. verify if the disconnection times have been achieved

11. evaluate thermal constraints

12. interpret the requirements of sources of information in the design of an installation