Demonstrate knowledge of theory for registration of electricians by sanmelody

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Demonstrate knowledge of theory for registration of electricians

Level                             4

Credits                           3

Purpose       This unit standard covers the theory assessment required for registration as
              an electrician.

              People credited with this unit standard are able to demonstrate knowledge of:
              – basic electrical principles;
              – electrical safety and safe working practices;
              – the New Zealand electricity supply system;
              – electrical protective devices;
              – electrical cables;
              – electrical switchboards;
              – electrical testing, inspection and certification;
              – transformers and their applications; and
              – electric motor applications.


Subfield                          Electrical Engineering

Domain                            Core Electrical

Status                            Registered

Status date                       19 June 2009

Date version published            19 June 2009

Planned review date               31 December 2014

Entry information                 Open.

Accreditation                     Evaluation of documentation and visit by NZQA and
                                  industry.

Standard setting body (SSB)       ElectroTechnology Industry Training Organisation

Accreditation and Moderation Action Plan (AMAP) reference                  0003
This AMAP can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.




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Special notes

1   As part of the requirement for registration as an Electrician, candidates must pass the
    EWRB Theory Examination, which is the only valid assessment tool for this unit
    standard. Credit for this unit standard may only be granted on evidence of a pass in
    the Electricians’ Theory Examination. This unit standard is the prime reference for
    this examination.

2   This unit standard, together with Unit 1702, Demonstrate knowledge of, and apply
    electrical legislation, codes of practice, and standards, satisfies the critical
    component of the Critical Capabilities of the Essential Capabilities for registered
    electricians as specified by the EWRB.

3   References
    Electricity Act 1992;
    Electricity Regulations 1997;
    Electricity Amendment Act 2006;
    Health and Safety in Employment Act 1992;
    AS/NZS 3000:2000 Electrical installations (known as the Australian/New Zealand
    Wiring Rules);
    AS/NZS 3008.1.2:1998 Electrical installations – Selection of cables – Cables for
    alternating voltages up to and including 0.6/1 kV – Typical New Zealand installation
    conditions;
    AS/NZS 3760:2003 In-service safety inspection and testing of electrical equipment;
    Electrical Workers Registration Board, Electricity Regulations Compilation 2003.
    Available from Legislation Direct, PO Box 12 357, Wellington;
    NZECP 34:2001 New Zealand Electrical Code of Practice for Electrical Safe
    Distances;
    NZS 3019:2002 (INT) Electrical installations – In-service testing;
    Electrical Workers Registration Board and Ministry of Economic Development,
    Supervision procedures for Trainee Electricians; (April 2007),
    and all subsequent amendments and replacements.

4   The term current regulations and standards is used in this unit standard to refer to
    the requirements of the above references.

5   Definitions
    a.c. – alternating current.
    d.c. – direct current.
    e.m.f. – electromotive force.
    EWRB – Electrical Workers Registration Board.
    HRC – high rupturing capacity.
    mcb – miniature circuit breaker.
    MEN – multiple earthed neutral (system of electricity supply).
    PELV – protected extra-low voltage.
    PVC – polyvinyl chloride.
    RCBO – residual current operated circuit breaker with overcurrent protection.
    RCCB – residual current operated circuit breaker.
    RCD – residual current device.
    SELV – separated extra-low voltage.
    SRCD – socket residual current protection device.
    PRCD – portable residual current protection device.



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      SWA – steel-wire armoured.
      TPS – tough plastic-sheathed.
      VA – volt-amps.
      XLPE – cross-linked polyethylene.

6     Assessments are ‘closed-book’. Non-programmable calculators are permitted.

Elements and performance criteria
Element 1

Demonstrate knowledge of basic electrical principles.

Performance criteria

1.1        The effects of electric current are described, and energy conversions outlined.

           Range         physiological, heat, chemical, magnetic, mechanical.

1.2        The operation of a simple practical electrical circuit is explained with reference
           to current path, circuit control, load, source of e.m.f., and conductors.

1.3        Direct current circuits are analysed to determine resistance, voltage, current,
           and power in any part of the circuit.

           Range         circuits containing one source of e.m.f., up to five resistances
                         connected in any combination, one internal resistance.

1.4        Quantity and cost of energy are calculated from given data for a simple
           domestic loading, and expressed in kilowatt-hours and dollars.

1.5        The nature of a.c. and its generation is described, and how voltage and current
           may be out of phase.

1.6        Alternating current power terminology is explained.

           Range         true power (P, Watts), reactive power (Q, volt-amps reactive or
                         VAr), apparent power (S, VA).

1.7        The concept of power factor is explained, with reference to its importance in
           economic terms, and how it may be measured and minimised.

1.8        Calculations involving currents, voltages, and powers in three-phase systems
           are performed.

           Range         power in star and delta connected resistive loads, line and phase
                         voltages and currents.

1.9        Electrical diagrams are sketched, read, and interpreted.

           Range         diagrams – block, schematic, wiring.



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Element 2

Demonstrate knowledge of electrical safety and safe working practices.

Performance criteria

2.1       Requirements of legislation and codes of practice relating to the safety of
          electrical workers are identified.

          Range        employer and employee responsibilities, competency
                       requirements, supervision requirements.

2.2       Electrical safe working practices are outlined in accordance with the EWRB and
          related industry requirements.

2.3       Concepts relating to working safely in the vicinity of high voltage equipment and
          distribution systems are outlined.

          Range        step and touch voltages, induced voltages, creepage and
                       clearance requirements, stored energy, earthing, safe working
                       procedures.

2.4       Rescue and first aid procedures for use in electrical accidents are outlined.

          Range        rescue of person in contact with live conductors or equipment, first
                       aid for electric shock victims.

2.5       Procedures for the safe isolation of electrical equipment and systems are
          explained.

          Range        sequential steps to achieve isolation and safe working
                       environment, prove-test-prove, test before touch, switch lock-off,
                       safety tag system, written isolation procedures.

2.6       The fundamental safety principles of AS/NZS 3000:2000, Section 1 are
          outlined.

Element 3

Demonstrate knowledge of the New Zealand electricity supply system.

Performance criteria

3.1       The operation of the New Zealand transmission system from power station to
          consumer is explained with the aid of a diagram.

          Range        diagram shows – alternator, transformers, transmission lines,
                       typical voltages before and after transformation, connection details
                       for single-phase, two-phase, and three-phase consumers. The
                       diagram is fully labelled and identifies active, neutral, and earth
                       conductors wherever used.




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3.2       The reasons for earthing the neutral at multiple points are stated, and the
          implication of a missing MEN link during fault conditions is outlined.

          Range        line voltage to earth, protective devices, fault current path.

3.3       The maximum allowable neutral-to-earth resistance is stated in accordance with
          current regulations and standards.

3.4       The need for a neutral conductor on an unbalanced star-connected load is
          explained, and neutral currents are determined graphically for given star-
          connected loads.

          Range        loads – purely resistive, mixed reactive.

Element 4

Demonstrate knowledge of electrical protective devices.

Performance criteria

4.1       The meanings of circuit protection terms are explained in accordance with
          industry practice.

          Range        current rating, voltage rating, fusing current, utilisation category,
                       tripping factor, cut-off characteristic, time versus current
                       characteristic, category of duty, discrimination, backup protection,
                       rupturing capacity, prospective short circuit current, coarse excess
                       current protection, close excess current protection, sensitivity,
                       earth-fault-loop impedance.

4.2       Merits of close excess current protection are explained in accordance with
          industry practice.

4.3       Protection devices are described with the aid of diagrams and reference to
          construction, operating principles, and applications.

          Range        devices – rewirable, cartridge, and HRC fuses; fusible links; mcbs;
                       magnetic and thermal overload relays; RCD.

4.4       The properties of different types of RCDs are explained.

          Range        RCCB, RCBO, SRCD, PRCD, residual current device that
                       functions independently of line voltage, residual current device that
                       is functionally dependant on line or auxiliary voltage, residual
                       current ratings for personal protection and property protection;
                       operation with a d.c. component present; load leakage currents.

4.5       Procedures for testing and verifying the operation of RCDs are described in
          accordance with current regulations and standards.

          Range        operating time, residual current.




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4.6       Merits of using SELV and PELV systems for protection against direct and
          indirect contact are explained in accordance with AS/NZS 3000:2000.

Element 5

Demonstrate knowledge of electrical cables.

Performance criteria

5.1       Maximum demand is calculated for a domestic or non-domestic installation in
          accordance with current regulations and standards.

5.2       Cable type and size are determined for given applications in accordance with
          current regulations and standards.

          Range        types of circuits – mains, submains, final subcircuits;
                       cables may be – flexible (PVC, TPS, rubber-sheathed), fixed
                       wiring (TPS, conduit wire, neutral screened cable, XLPE, SWA),
                       underground, aerial;
                       applications may require consideration of – conductor material,
                       maximum conductor temperature, cable type, installation method,
                       maximum demand, length of run, class of excess current
                       protection, grouping, current carrying capacity, short circuit
                       capability, voltage drop, earth loop impedance.

Element 6

Demonstrate knowledge of electrical switchboards.

Performance criteria

6.1       The meanings of the terms switchboard, main switchboard, MEN switchboard,
          distribution switchboard, and switchgear are defined in accordance with current
          regulations and standards.

6.2       Switchboard circuitry is explained with the aid of sketches.

          Range        MEN switchboard, distribution switchboard, main switchboard,
                       earthing arrangements, control devices, protective devices.

6.3       Earth-fault-loop impedance and prospective short circuit current are assessed
          for a domestic installation.

6.4       Switchboard control and protective devices are selected for given applications
          in accordance with current regulations and standards.




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Element 7

Demonstrate knowledge of electrical testing, inspection and certification.

Performance criteria

7.1       The terms testing, inspection and certification are explained in accordance with
          current regulations and standards.

7.2       The checks and tests to be performed to ensure electrical installations are safe
          are identified and methods of measurement described, in accordance with
          current regulations and standards. Where appropriate, minimum and maximum
          values are quoted.

          Range         checks and tests – visual tests, continuity of the earthing system,
                        insulation resistance, polarity, correct circuit connections,
                        operation of RCDs, fault-loop impedance.

7.3       The in-service inspections and tests to be performed on electrical equipment
          are described in accordance with current legislation and standards.

7.4       Types of installations requiring inspection by a registered electrical inspector
          prior to connection to the power supply are identified in accordance with current
          legislation.

7.5       Certification documentation requirements are explained in accordance with
          current legislation.

Element 8

Demonstrate knowledge of transformers and their applications.

Performance criteria

8.1       Typical applications of transformers are described and key safety issues
          identified.

          Range         step-up and step-down of voltage and current, safety isolation,
                        safety extra-low voltage source, instrumentation, reduced-voltage
                        motor starters, variable-voltage supplies, welding equipment.

8.2       The reason for rating transformers in volt-amps rather than in Watts is
          explained.

8.3       Calculations are made involving transformer primary and secondary currents
          and voltages, turns and turns ratios, VA rating, and efficiency, for different
          winding configurations.

          Range         configurations – single-phase, star-star, delta-delta, star-delta,
                        delta-star.




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Element 9

Demonstrate knowledge of electric motor applications.

Performance criteria

9.1       The operation of motor starters is explained with the aid of diagrams, and the
          features of motor starters are compared.

          Range         block diagram of electronic starter;
                        circuit diagrams of – direct-on-line, star-delta, auto-transformer,
                        primary resistance, secondary resistance.

9.2       Characteristics of motor starters are compared.

          Range         motor starters – direct-on-line, star-delta, auto-transformer,
                        primary resistance, secondary resistance, electronic;
                        characteristics – starting current and torque, full load current and
                        torque, cost.

9.3       Protective features incorporated in electric motors and starters are described.

          Range         overcurrent, no-volt, phase reversal, phase failure, mechanical
                        stress, temperature.

9.4       Electric motors are selected for given applications.

          Range         selections to take into account any or all of – single-phase, three-
                        phase, load, torque, starting conditions, protection, environment.

Please note

Providers must be accredited by NZQA, or an inter-institutional body with delegated
authority for quality assurance, before they can report credits from assessment against
unit standards or deliver courses of study leading to that assessment.

Industry Training Organisations must be accredited by NZQA before they can register
credits from assessment against unit standards.

Accredited providers and Industry Training Organisations assessing against unit standards
must engage with the moderation system that applies to those standards.

Accreditation requirements and an outline of the moderation system that applies to this
standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The
AMAP 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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Comments on this unit standard

Please contact the ElectroTechnology Industry Training Organisation (ETITO)
reviewcomments@etito.co.nz if you wish to suggest changes to the content of this unit
standard.




                                                             New Zealand Qualifications Authority 2011

								
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