AM2E Pre-April 2010 - Testing and Safe Isolation Unit

What will I learn?

This is NOT a training course, it is an assessment of competencies

For this unit, you’ll need to carry out three safe isolation tasks and then carry out a visual inspection of an installation and complete a series of tests following practices and procedures that take into account electrically sensitive equipment.

Maximum Time Allowed:

• Safe Isolation: 30 minutes plus 5 minutes to read and prepare
• Testing: 3 hours 30 minutes, plus 20 minutes to read and prepare

Safe Isolation Task:

The safe isolation procedure will be observed by the Centre Assessor. To demonstrate occupational competence, you will have to carry out safe isolation in the correct sequence to allow for the following tasks:

Note: for Tasks 1 & 2 all other circuits must remain energised.

• Task 1: To replace a single-phase piece of equipment
• Task 2: To replace a three-phase piece of equipment
• Task 3: To isolate the distribution board in your fault diagnosis bay

SAFE ISOLATION PROCEDURE

• Identify your point of isolation
• Inform the customer that you will be isolating the supply
• Operate the isolator and lock off and fit warning notice
• Select approved test equipment and prove that it is working
• Test on the outgoing side of isolator all combinations:
  • L1 and L2
  • L1 and L3
  • L1 and Neutral
  • L1 and Earth
  • L2 and L3
  • L2 and Neutral
  • L2 and Earth
  • L3 and Neutral
  • L3 and Earth
  • Neutral and Earth
• Re-prove your test equipment is working

Testing, Inspection and Certification Task:

This section will be observed by the Centre Assessor. You will be provided with the following documentation for use throughout the section:

• BS 7671 Requirements for Electrical Installations
• IET Guidance Note 3. Inspection & Testing
• IET On-Site Guide

To demonstrate occupational competence, you’ll carry out a visual inspection of your installation and complete the following tests:

• Continuity of protective conductors, including main and supplementary bonding
• Continuity of ring final circuit conductors
• Insulation resistance
• Polarity
• Earth fault loop impedance
• Additional protection (effectiveness of RCDs)
• Prospective fault current
• Check of phase sequence
• Functional testing

You also need to correctly complete an Electrical Installation Certificate, Schedule of Circuit Details and Schedule of Test Results and verify selected results comply with BS 7671, using the documentation provided.

You can download blank template forms if you wish to familarise yourself with these documents before your assessment.

You’ll be expected to follow practices and procedures that consider the presence of voltage sensitive equipment.

Industry placement, field trips and guest speakers

None