EAS Electrical Appliance Serviceperson Answer Schedule

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Erick Marcus Nicholson
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1 EAS Electrical Appliance Serviceperson Answer Schedule Notes:1. means that the preceding statement/answer earns 1 mark. 2. This schedule sets out the expected answers to the examination questions. The marker can exercise their discretion and decide on the overall accuracy of any answer that is presented in the candidate s own words. Question 1 Reference Marks Marking notes Each part in this question is worth 2 marks (a) 1 MΩ answer - (4) (b) Highest heating effect answer (3) (c) Water - gas expelled answer (1) (d) A double insulated electrical appliance answer (2) (e) 746 watts answer (2) (f) A difference in voltage exists to earth or between conductors answer (1) (g) Disconnect a large fault current answer (3) (h) Verify that the resistance is low enough to ensure protection will operate under fault conditions answer (4) (i) 0V answer - (2) (j) 230V answer (3) FINAL - EAS 1083 ANSWERS 17 JUNE

2 Question 2 Marks Reference Marking notes (a) (i) Insulation resistance tester 250V d.c * 500V d.c Any ONE of * Bridge the phase and neutral together on the plug. Test between the bridge and the frame of the appliance. * Test between the phase pin on the plug and the frame of the appliance. Test between the neutral pin on the plug and the frame of the appliance. 500V d.c Bridge the phase and neutral together on the plug. Test between the bridge and the frame of the appliance. The test voltage can be either 250V or 500V. Whichever is chosen, the applicable testing method applies 1 MΩ minimum (ii) Any ONE of: * Earth leakage tester * Clip-on ammeter Test the leakage current in the protective earthing conductor. 5 ma maximum. (b) Any ONE of: To ensure that the Protective Earthing conductor is continuous and of a resistance less than 1 ohm. To ensure that a false reading is not obtained if the Protective Earthing Conductor resistance is very high or is open-circuited. FINAL - EAS 1083 ANSWERS 17 JUNE

3 Question 3 Marks Reference Marking notes (a) A capacitor-start motor (b) 1. Start winding 2. Start Capacitor 3. Centrifugal switch 4. Run winding (c) Any ONE of: Reverse the connections of 1 - the start winding Reverse the connections of 4 - the run winding. (d) (i) The motor would not start. (ii) There is no phase displacement between the start and run windings So no rotating magnetic field is established. (e) The motor would slow down until the centrifugal switch closed. The motor will speed up again as the start winding is energised. The centrifugal switch will open at around 75% full-load speed so the motor will cycle as the switch opens and closes. FINAL - EAS 1083 ANSWERS 17 JUNE

4 Question 4 Marks Reference Marking notes (a) Any TWO of: Avoiding contact with live terminals. Wearing personal protective equipment. Ensuring that all loads have been removed from the circuit. (b) Switched off means the appliance is no longer supplied with electricity. Isolated means the appliance has been deliberately disconnected from the electricity supply. And steps taken to prevent reconnection. (c) Any ONE of: Attaching a safety warning tag. Fit a lockable cover to the plug. (d) Any FOUR of: Inspect instrument, clips, leads and probes to ensure they are in good condition. Ensure correct function is selected on the instrument. Ensure correct (or highest) range is selected on the instrument. Ensure leads are correctly connected. Ensure meter testing voltage is connected in parallel Ensure meter testing current is connected in series. (4 marks) FINAL - EAS 1083 ANSWERS 17 JUNE

5 Question 5 Marks Reference Marking notes (a) (i) Three cores Any ONE of: * Brown (3 marks) To gain marks, Light blue (or blue) one set must Green/yellow be stated accurately * Red Black Green (ii) Two Any ONE of: * Brown Light blue (or blue) * Red Black To gain marks, one set must be stated accurately (b) (i) Failure will be by melting of sheath and/or insulation deterioration due to heat build-up (ii) Any ONE of: Fully unwind the cord from the drum. Reduce the load supplied by the flexible cord. (c) It is the maximum current the cord is designed to carry safely. FINAL - EAS 1083 ANSWERS 17 JUNE

6 Question 6 Marks Reference Marking notes (a) P N (b) P N (c) (i) I = V R = = 4.35 A (ii) P = V 2 R = 230 x = 500 W (iii) RT = Product Sum = 52.9 x = Ω P = V 2 FINAL - EAS 1083 ANSWERS 17 JUNE

7 Question 6 Marks Reference Marking notes R = 230 x = 2000 W FINAL - EAS 1083 ANSWERS 17 JUNE

8 Question 7 Marks Reference Marking notes (a) (i) A clip-on ammeter. (1½ marks) (ii) The procedure must show: Turning the appliance on and selecting the correct setting. Clamping the meter around the phase or neutral conductor Recording the current drawn on each setting. (b) (i) An ammeter Or A multimeter (1½ marks) (ii) Any ONE of: The procedure must show: * Isolating the appliance using the prove-testprove method * Connecting the ammeter in series with the phase conductor * Turning the appliance on * Recording the current drawn on each setting. The procedure must show: * Isolating the appliance using the prove-testprove method * Connecting the multimeter between phase and neutral. * Recording the ohms reading on each setting. * Calculating the current drawn on each setting. FINAL - EAS 1083 ANSWERS 17 JUNE

9 Question 8 Marks Reference Marking notes (a) Current rating Voltage rating Category of duty (Rupturing Capacity) Utilisation category (fusing factor) (Class) (b) (i) The fuse could blow before the final subcircuit full-load current is reached. (ii) The current may increase to a high level causing damage to the final subcircuit before the fuse blows. (c) Any TWO of: If the fuse blows again an arc may be established between the fuse terminals causing damage or injury Cannot safely interrupt short circuit currents of much higher values. Fuse wire may protrude past the holder which creates an exposure to shock. Suitable fixing for the fuse wire is not generally available. Fuse holder is not fire proof. (d) Any TWO of: To ensure the fuse element is not accessible to touch. Under overload conditions the heat produced in the element is confined to the tunnel area. Under short-circuit conditions the arc and molten element is confined within the fuse carrier and base. FINAL - EAS 1083 ANSWERS 17 JUNE

10 Question 9 Marks Reference Marking notes (a) Means the Multiple Earthed Neutral System which is a New Zealand variant of the internationally defined TNC system of supply of electricity in which the neutral is connected to earth: (a) at the source of supply; and (b) at points on the supply system; and (c) at every electrical installation connected to that system. ESR 4 (b) In respect of electricity supplied by either as single-phase MEN system or multiple-phase MEN system, a nominal voltage of 230 volts a.c. between phase and neutral ESR 4 (c) Phase to Phase = 400V Phase to Neutral = 230V Phase to Earth = 230V Neutral to Earth = 0 V (d) Peak = 325 V RMS = 230 V seconds or 20 milliseconds Time interval correctly shown Time interval value correct Peak voltage correctly shown Peak voltage value correct RMS voltage correctly shown RMS voltage value correct Axes symmetrical Wave the correct shape FINAL - EAS 1083 ANSWERS 17 JUNE

FINAL - EST Electrical Service Technician Answer Schedule

FINAL - EST Electrical Service Technician Answer Schedule FINAL - EST 2069 - Electrical Service Technician Answer Schedule Notes:1. means that the preceding statement/answer earns 1 mark. 2. This schedule sets out the accepted answers to the examination questions.