17801 Demonstrate Knowledge of Single-Phase Motors for Electrical Appliance Servicing

Explanatory notes

1This unit standard has been developed for learning and assessment off-job.

2Competency under this unit standard does not entitle the candidate to legally perform prescribed electrical work withoutadequate supervisionuntil the candidate has been registered and licensed under the Electricity Act 1992.

3References

Electricity (Safety) Regulations 2010;

Electricity Act 1992;

Health and Safety in Employment Act 1992, and associated regulations;

New Zealand Electrical Codes of Practice(Ministry of Business, Innovation and Employment, ISSN0114-0663);

AS/NZS 3000:2007, Electrical Installations (known as the Australian/New Zealand Wiring Rules);

AS/NZS 3760:2010, In-service safety inspection and testing of electrical equipment including Amendment 1;

and all subsequent amendments and replacements.

4Definitions

Electrical technicians and service persons – for the purposes of this unit standard means, people who hold or who are working towards electrical registration as an Electrical Service Technician, Electrical Appliance Serviceperson (endorsed to disconnect and connect), or Electrical Appliance Serviceperson.

Industry practice – those practices which competent practitioners within the industry recognise as current industry best practice.

5Range

Electric motors – universal, shaded pole, standard split-phase, capacitor-start, capacitor-start-and-run, permanently split.

Evidence of at least two motors is required.

Outcomes and evidence requirements

Outcome 1

Explain operating principles of single-phase electric motors.

Evidence requirements

1.1Motor operating principle is explained with reference to circuit diagram, construction and connection of stator and rotor, production of rotating magnetic field, and method of starting.

Rangereference to mathematical formulae is not required;

circuit diagrams should be produced from memory.

1.2The method of reversing the direction of rotation is stated.

1.3A typical application is stated in accordance with industry practice.

1.4Overload protection is explained with reference to one type of device in accordance with industry practice.

1.5Method of speed control is explained in simple terms, with reference to a circuit diagram.

1.6A typical radio interference suppression circuit is described for one single-phase motor with reference to circuit diagram, typical component values, component ratings, and maximum permitted component values.

Outcome 2

Connect and test single-phase electric motors.

Evidence requirements

2.1Safety inspection and testing in accordance with AS/NZS 3760 confirms that the motor is safe to connect to the supply.

2.2Motor is connected to the electricity supply in accordance with industry practice and Electricity Regulations.

2.3Observation and electrical testing confirms safe motor operation in accordance with industry practice.

Rangeobservation – direction of motor rotation, smooth and quiet running, operation of centrifugal starter switches where appropriate;

tests – polarity, continuity of earthing, on/off switching, live rated-voltage, no-load current, full-load current, comparison with name plate values.

2.4Direction of rotation is reversed in accordance with industry practice.

2.5A radio interference suppression circuit is replaced on one motor in accordance with industry practice.

Status information and last date for assessment for superseded versions

This CMR can be accessed at

Please note

Providers must be granted consent to assess against standards (accredited) by NZQA, before they can report credits from assessment against unit standards or deliver courses of study leading to that assessment.

Industry Training Organisations must be granted consent to assess against standards by NZQA before they can register credits from assessment against unit standards.

Providers and Industry Training Organisations, which have been granted consent and which are assessing against unit standards must engage with the moderation system that applies to those standards.

Requirements for consent to assess and an outline of the moderation system that applies to this standard are outlined in the Consent and Moderation Requirements (CMR). The CMR also includes useful information about special requirements for organisations wishing to develop education and training programmes, such as minimum qualifications for tutors and assessors, and special resource requirements.

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