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Electrotechnology 2009 HSC Specimen examination – Sample marking guidelines

Section II, Question 20

Competencies assessed: UEENEEE004B

Marking guidelines

Criteria	Marks
Correctly calculates the value of the unknown resistor	2
Makes progress in calculating the value of the unknown resistor, such as calculating the voltage VRX	1

Sample answer/Answer may include:

If the motor is to operate with a voltage of 6 volts, then the voltage drop across the resistor RX must also be 6 volts.

From Ohm’s law:

Question 25 (d)

Competencies assessed: UEENEEE002B

Marking guidelines

Criteria	Marks
Demonstrates a thorough understanding of procedures to be followed in dismantling and reassembling a fan motor, and indicates the most appropriate tools for each step in the procedure	5
Demonstrates a substantial understanding of procedures to be followed in dismantling and reassembling a fan motor, and indicates several appropriate tools for the procedure	4
Demonstrates a basic understanding of procedures to be followed in dismantling and reassembling a fan motor, and indicates one or two appropriate tools for the procedure	3
Lists ONE or TWO steps in dismantling or reassembling a fan motor, or one or more tools required for this procedure	1–2

Sample answer/Answer may include:

Step 1: Remove all dirt or grease from the motor – rags, scraper and degreasers
Step 2: Remove the drive pulley from the drive shaft – allen key and bearing puller
Step 3: Remove fan cover and fan – screwdrivers, allen keys and bearing puller
Step 4: Check axial float of the shaft – ruler
Step 5: Install location marks on the end shields – hammer and centre punch
Step 6: Remove end shield holding screws, then end shields – screwdrivers, soft drift, softfaced mallet and wedges.
Step 7: Withdraw the rotor from the motor starter
Step 8: Remove the old bearings from the rotor – bearing puller
Step 9: Thoroughly clean all parts – rags and degreaser
Step 10: Fit new bearings, grease if not sealed – bearing heater, soft drift / tube, soft-faced hammer
Step 11: Reverse from Step 6 to reassemble the motor.

Section III, Question 27

Competencies assessed: UEENEEE001B, UEENEEE005B

Marking guidelines

Criteria	Marks
Demonstrates a clear understanding of risk management and the hierarchy of risk control Provides a comprehensive description of risk control measures that could be implemented in the given situation Communicates ideas and information effectively in a well-reasoned, cohesive response, using language appropriate to the audience and purpose Uses appropriate electrotechnology examples of risk control measures using correct industry terminology	13–15
Demonstrates an understanding of risk management and the hierarchy of risk control Provides a detailed description of several risk control measures that could be implemented in the given situation Communicates ideas and information using language appropriate to the audience and purpose Uses some examples of risk control measures using correct industry terminology	10–12
Demonstrates some understanding of risk management or the hierarchy of risk control Provides an outline of several risk control measures that could be implemented in the given situation Communicates using some language appropriate to the audience and purpose Uses some examples of risk control measures using general terminology	7–9
Demonstrates limited understanding of some aspects of risk management or the hierarchy of risk control Lists a few risk control measures of varying relevance to the given situation Communicates using non-technical language	4–6
Lists one or two risk control measures Limited written communication skills demonstrated	1–3

Sample answer/Answer may include:

The first step is to perform a risk assessment that will identify and assess any hazards that require controlling. We must then try to eliminate the identified hazards, if this is not possible we must minimise the risks associated with the hazards or use other controls such as PPE.

The following is a list of hazards:

• electric arc furnace – heat, noise, dust, possibility of sparks and flames, flammable materials
• overhead and mobile machinery working in the area
• other people working in the area
• hydraulic and electrical equipment need to be isolated.

A hierarchy of risk control measures can be applied to the hazards as follows:

Level 1 – Elimination: the first control option to be considered is whether it is feasible to completely remove all the hazards. In this case it is not possible to eliminate all hazards, so we need to proceed to the next level which is to minimise the risk.

Level 2 – Minimisation: several measures should be considered, such as:

• isolating the hazards (electric arc furnace etc) by introducing a restrictive work area to prevent other people working in this area
• substituting – you can substitute the work practice with a procedure that has less potential to cause injury. In this is situation it is not practical, so I would proceed to the next level.

Level 3 – other controls including: Personal Protective Equipment is used as a means of shielding workers from potential hazards. In relation to the hazards you would wear ear protection, eye protection, hard hat, protective gloves, steel capped boots, dust mask and leather jacket.

When deciding on the methods of controlling the hazards it is important that an evaluation of the processes and procedures chosen is carried out to guarantee that these types of control will not introduce new hazards. Information and training needs to be provided to all concerned employees to ensure they are safe from injury and risks.

Finally the control measures implemented should be monitored and reviewed.