The unit applies to a wide variety of generators/alternators and both electro-mechanical and specialist electronic regulating apparatus, and the testing and rectification work associated with 12, 14, and 36 volt charging systems on vehicles, plant and stationary equipment.

All work is carried out to legislative and regulatory requirements.

If specialist electronic skills are required, appropriate competency units should be selected.

This unit should not be selected with any of the following units: MEM18045B (Fault find/repair electrical equipment/components up to 250 volt single phase supply) or Unit MEM18046B (Fault find/repair electrical equipment/components up to 1000 volts a.c./1500 volts d.c.).

If soldering of wires is required, see Unit MEM05001B (Perform manual soldering/desoldering - electrical/electronic components).

Band: A

Unit Weight: 2

Path 1

MEM09002B

Interpret technical drawing

MEM12023A

Perform engineering measurements

MEM18001C

Use hand tools

MEM18002B

Use power tools/hand held operations

MEM18030B

Diagnose and rectify low voltage electrical systems

MEM18055B

Dismantle, replace and assemble engineering components

ELEMENT

PERFORMANCE CRITERIA

1. Assess generator/alternator operation

1.1. Magnetism, induced voltage and electromagnetism principles are understood.

1.2. Alternating and direct current generating principles, voltage/current regulation methods, and diode/condenser types and action are understood.

1.3. Charging system performance is checked and variances from system specifications are accurately recorded.

2. Test and rectify generators/alternators

2.1. Generators/alternators are dismantled and assembled correctly.

2.2. Charging faults are determined to component level.

2.3. Testing is performed to determine shorts to ground, turn shorts and winding continuity etc.

2.4. Alternator/generator is tested for normal and maximum output.

2.5. Voltage and/or current regulators and cut-outs and relays are correctly tested and adjusted to specification.

2.6. Condition of power/exciter diodes is correctly determined.

2.7. All faulty components are replaced according to manufacturers' recommendations i.e.: brush gear, bearings, diodes, contacts, relays, etc.

2.8. Charging system is free of excessive voltage drops and connections are correctly soldered, tightened and insulated.

Required skills

Look for evidence that confirms skills in:

reading, interpreting and following information on written job instructions, specifications, standard operating procedures, charts, lists, drawings and other applicable reference documents

planning and sequencing operations

checking task-related information

checking for conformance to specification

testing the charging system for correct operation

recording variations from system specifications

dismantling and reassembling given generators/alternators

identifying charging faults in given generator/alternator systems

conducting short circuit and winding continuity tests

testing the given alternator/generator output for conformance to specification

testing given voltage and current regulators, cut-outs and relays for correct operation and conformance to specifications

determining the condition of given power/exciter diodes

replacing faulty components

checking the given generator/alternator charging system for excessive voltage drops

undertaking calculations and numerical operations within the scope of this unit

recording and reporting service activities

Required knowledge

Look for evidence that confirms knowledge of:

the concepts of magnetism, electromagnetism and induced voltage

the construction of generators

the principles of operation of generators and alternators

the methods of generating alternating and direct current for low voltage systems

the methods of regulating voltage and current generated

the function of diode and condenser types of regulator

the tests that can be used to check the performance of the charging system

the test procedures

the hazards associated with testing the performance of the charging system, including housekeeping

the charging system specifications

the test equipment to be used in checking low voltage charging systems

the procedures for recording charging system performance/variations from specifications

the procedures for dismantling and reassembling generators/alternators

the tools and equipment to be used in dismantling and reassembling generators/alternators

the safety precautions and work procedures to be followed when working with generators/alternators

the procedures and test equipment for identifying charging faults

the procedures and test equipment for testing short circuits and winding continuity

the specifications of generator/alternator output

the test equipment and procedures to be used to determine alternator/generator output

the procedures for testing voltage and current regulators, cut-outs and relays

the methods of adjusting voltage and current regulators, cut-outs and relays

the operational specifications of voltage and current regulators, cut-outs and relays

the test equipment to be used to check the operation of voltage and current regulators, cut-outs and relays

the procedures for testing diodes and the test equipment to be used

the precautions to be taken when testing diodes

the components of generators/alternators that can be replaced

the specifications of the faulty generator/alternator components

the effect and causes of voltage drops on charging system operation/ performance

the procedures for checking charging systems for excessive voltage drops

the effect of loose, poorly soldered and/or inappropriate insulation on charging system operation

the specifications of all circuit connections

safe work practices and procedures

The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.

Overview of assessment

A person who demonstrates competency in this unit must be able to diagnose and rectify low voltage charging systems. Competency in this unit cannot be claimed until all prerequisites have been satisfied.

Critical aspects for assessment and evidence required to demonstrate competency in this unit

Assessors must be satisfied that the candidate can competently and consistently perform all elements of the unit as specified by the criteria, including required knowledge, and be capable of applying the competency in new and different situations and contexts.

Context of and specific resources for assessment

This unit may be assessed on the job, off the job or a combination of both on and off the job. Where assessment occurs off the job, that is the candidate is not in productive work, then an appropriate simulation must be used where the range of conditions reflects realistic workplace situations. The competencies covered by this unit would be demonstrated by an individual working alone or as part of a team. The assessment environment should not disadvantage the candidate.

This unit could be assessed in conjunction with any other units addressing the safety, quality, communication, materials handling, recording and reporting associated with diagnosing and rectifying low voltage charging systems, or other units requiring the exercise of the skills and knowledge covered by this unit.

Method of assessment

Assessors should gather a range of evidence that is valid, sufficient, current and authentic. Evidence can be gathered through a variety of ways including direct observation, supervisor's reports, project work, samples and questioning. Questioning techniques should not require language, literacy and numeracy skills beyond those required in this unit of competency. The candidate must have access to all tools, equipment, materials and documentation required. The candidate must be permitted to refer to any relevant workplace procedures, product and manufacturing specifications, codes, standards, manuals and reference materials.

Guidance information for assessment

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

Unit sector

Maintenance and diagnostics

This unit contains employability skills.