SCQF Level 8


40 Hours over 6 Months


30 Aug 2019




  • Engineering

Why take this course?

This Unit has been designed to provide you with an opportunity to develop your knowledge and understanding of the design of electrical installations. If you already have some working knowledge of electrical installations, some of these design concepts may be familiar to you. If, on the other hand, this is your first contact with electrical installations and their design, the Unit should provide you with an understanding of the design methods and their relationship to the relevant British Standard, current BS 7671.

What you will experience

A key factor in any Unit related to the use of electrical energy is safety, and this emphasised in the design of an electrical installation. The design of an electrical installation must provide for the safety of the persons using the electrical equipment in the facility and must also protect the facility itself against the risk of fire. In order to achieve this, the ‘Wiring Regulations’ current (BS 7671) set out various requirements relating to the methods of installation of cables, conductors and equipment and to the protection of circuits against overheating should faults occur. An important addition to this is also the protection of persons against the risk of electric shock.

Outcome 1 deals at length with the terminology used in relation to overcurrent protection and an analysis of the devices used to protect circuits against currents above the expected value for that circuit. It considers the factors to be taken into account when choosing the most appropriate overcurrent protection device.

Outcome 2 considers the requirements for earthing the installation as one method of reducing the risk to persons of electric shock. It outlines the requirements of current BS 7671 in relation to an analysis of shock prevention and considers how this is achieved in practice.

Outcome 3 analyses the factors to be considered when selecting cables for given load and environmental conditions. The cable must have a sufficient cross-sectional area to carry the circuit current and the type of cable and its method of installation must be such that it will not suffer damage or degradation during its normal lifetime. The requirements of current BS 7671 are also very important in the choice of cables for given conditions and emphasis is placed on these requirements.

Outcome 4 brings together all the strategies and concepts developed in the previous Outcomes and allows you to carry out a simple design exercise. You will be given a limited specification for part of an installation and asked to select the cable sizes, types of cable, switchgear, earthing arrangements and installation methods and to produce documentation to support your work. This design exercise will be assessed and will give you the confidence to undertake installation design under practical working condition.