Electrical Principles

This unit is expiring
The expiry date of this unit is 31/07/2024.

Overview

Framework:
Access to HE
Level:
Level 3
Unit No:
QU007906
Credits:
3
Guided learning hours:
Not available

Qualification Grading Type

Graded

Grade Descriptors

  • GD1-Understanding the subject
  • GD3-Application of skills
  • GD7-Quality

Unit Learning Outcomes

1

Understand waveforms and determine the main parameters used to describe and measure them.

Assessment Criteria

  • 1.1
    Define the terms amplitude, period, frequency, instantaneous, peak-to-peak, r.m.s., average in relation to alternating (sinusoidal and non-sinusoidal) and unidirectional waveforms.
  • 1.2
    Define form factor and determine the approximate average and r.m.s. value of given sinusoidal waveforms.
2

Be able to apply phasor and algebraic representation of sinusoidal quantities.

Assessment Criteria

  • 2.1
    Define a phasor quantity.
  • 2.2
    Determine the resultant of the addition of two sinusoidal voltages by graphical and phasor implementation.
  • 2.3
    Explain the phase angle relationship between the two alternating quantities.
  • 2.4
    Define a sinusoidal voltage in the form v = Vmsin(omega t + phi).
3

Be able to apply the basic theory of balanced three-phase circuits to the solution of problems.

Assessment Criteria

  • 3.1
    Describe the nature of, and summarise the reasons for, a three-phase supply network, with reference to the National Grid distribution system.
  • 3.2
    Explain the need for star and delta connections for power distribution and distinguish between delta and star (3 wire and 4 wire) methods of connection.
  • 3.3
    Apply the basic relationships between line and phase quantities under balanced conditions to solve single problems.
  • 3.4
    Explain the power dissipation in a three-phase load is the sum of the single-phase powers and that the power in a balanced three-phase load is: square root of 3.VLINE.ILINE.COS phi.