A/503/9950 Describe how electricity is generated and transmitted for domestic and industrial/commercial consumption.

Principles of Electrical Science

Aim: The aim of this unit is to enable the candidate to understand the principles of electrical science related to AC theory, machines, devices and systems. This understanding is applied when designing wiring systems for clients and fault diagnosis.

Learning outcome.

1 Understand electrical supply systems.

1. describe how electricity is generated and transmitted for domestic and industrial/commercial consumption.

2. specify the features and characteristics of a generation and transmission system.

3. state the basic operating principles of other sources of electricity.

4. describe the main characteristics of:

a. single phase electrical supplies.

b. three phase electrical supplies.

c. three phase and neutral supplies.

d. sub-station transformers.

5. identify types of transformers.

6. describe the operating principles, applications and limitations of transformers.

7. determine by calculation and measurement:

a. primary and secondary voltages.

b. primary and secondary current.

c. kVA rating of a transformer.

2 Understand how different electrical properties can affect electrical circuits, systems and equipment.

1. explain the relationship between resistance, inductance, capacitance and impedance.

2. determine electrical quantities in alternating current circuits.

3. explain the relationship between kW, kVAr, kVA and power factor.

4. calculate power factor.

5. explain what is meant by power factor correction.

6. specify methods of power factor correction.

7. determine the neutral current in a three-phase and neutral supply and why systems should be balanced.