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Evidence Guide: MEM18031B - Diagnose and rectify low voltage starting systems

Student: __________________________________________________

Signature: _________________________________________________

Tips for gathering evidence to demonstrate your skills

The important thing to remember when gathering evidence is that the more evidence the better - that is, the more evidence you gather to demonstrate your skills, the more confident an assessor can be that you have learned the skills not just at one point in time, but are continuing to apply and develop those skills (as opposed to just learning for the test!). Furthermore, one piece of evidence that you collect will not usualy demonstrate all the required criteria for a unit of competency, whereas multiple overlapping pieces of evidence will usually do the trick!

From the Wiki University

 

MEM18031B - Diagnose and rectify low voltage starting systems

What evidence can you provide to prove your understanding of each of the following citeria?

Assess starting motor operation

  1. Magnetism, induced voltage and electromagnetism and electric motor principles are understood.
  2. Starting motor component functions and multi-pole/winding/shunt wiring arrangements are understood.
  3. Cranking motor drive mechanism is correctly performance tested.
  4. Starter locked armature current, voltage and torque are correctly determined.
Magnetism, induced voltage and electromagnetism and electric motor principles are understood.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Starting motor component functions and multi-pole/winding/shunt wiring arrangements are understood.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Cranking motor drive mechanism is correctly performance tested.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Starter locked armature current, voltage and torque are correctly determined.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Test and rectify starting motors

  1. Starting motors are dismantled and assembled according to manufacturers' recommendations.
  2. Testing is performed to determine shorts to ground, turn shorts, winding continuity, etc.
  3. Solenoid, relays and over-temperature devices are correctly tested.
  4. Starter engagement mechanism is tested and adjusted where possible i.e.: pinion clearance.
  5. Starting system is free of excessive voltage drops.
  6. Starting and charging circuit connections are correctly made, tightened and insulated.
  7. Starter locked armature current, voltage and torque are correctly determined.
Starting motors are dismantled and assembled according to manufacturers' recommendations.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

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

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Solenoid, relays and over-temperature devices are correctly tested.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Starter engagement mechanism is tested and adjusted where possible i.e.: pinion clearance.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Starting system is free of excessive voltage drops.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Starting and charging circuit connections are correctly made, tightened and insulated.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Starter locked armature current, voltage and torque are correctly determined.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Assessed

Teacher: ___________________________________ Date: _________

Signature: ________________________________________________

Comments:

 

 

 

 

 

 

 

 

Instructions to Assessors

Evidence Guide

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 test and rectify low voltage starting 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 testing and rectifying low voltage starting 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

Required Skills and Knowledge

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

identifying the construction of electric motors

testing the cranking motor drive mechanism

using appropriate tools, techniques and equipment to dismantle and assemble given starting motors in accordance with manufacturers' recommendations/procedures

checking given starting motors for electrical faults

testing the solenoids, relays and over-temperature devices for given starting motors, for conformance to specification

checking operation and conformance of the engagement mechanism for given starting motors

checking the starting system of given starting motors for excessive voltage drops

checking conformance of all circuit connections to specifications for given starting motors

testing the repaired/overhauled starting motor to ensure that the locked armature current, voltage and torque conform to specifications

Required knowledge

Look for evidence that confirms knowledge of:

the concepts of magnetism, electromagnetism and induced voltage

the principles of operation of electric motors

the components and functions of common starting motors

the effect of multi-pole/winding/ shunt wiring arrangements on starting motor performance

the tests and test procedures that can be used to check the performance of the cranking motor drive mechanism

the hazards and control measures associated with testing the performance of cranking motor drive mechanisms, including housekeeping

the concept of 'locked armature' in terms of current, voltage and torque

the starter locked armature specifications

the procedures, tools and equipment for determining locked armature current, voltage and torque

the manufacturers' recommended dismantling/assembling procedures, tools and equipment for given starting motors

the range of electrical tests that can be applied to starting motors and the purpose of these tests

the equipment and procedures required to carry out the tests

the function of solenoids, relays and over-temperature devices

the procedures for testing solenoids, relays and over-temperature devices for correct operation

the operational specifications of the solenoids, relays and over-temperature devices

the procedures for testing and adjusting starter engagement mechanisms

the specifications of the starter engagement mechanism

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

the procedures for checking starting systems for excessive voltage drops

the effect of loose, poorly joined and/or inappropriate insulation on starting motor performance/operation

the specifications of all circuit connections

safe work practices and procedures

Range Statement

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.

Starting motor

Axial and coaxial type starters with drive arrangements such as Dyer, Positork, Sprag clutch, overrunning clutch and inertia drive