Тест: ПМ 5
Список вопросов
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1. 1. What is the purpose of night inspections for overhead power transmission lines? |
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| 1) D. To perform emergency measures after accidents | |
| 2) C. To measure the insulation resistance of insulators | |
| 3) B. To assess the quality of work of electricians | |
| 4) A. To visually check the condition of overhead line elements | |
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2. 2. How often are day inspections, the main type of inspections, carried out for overhead power transmission lines? |
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| 1) D. Annually | |
| 2) B. Monthly | |
| 3) C. Biannually | |
| 4) A. Weekly | |
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3. 3. What is the minimum horizontal distance required for the security zone of overhead lines up to 20 kV? |
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| 1) D. 10 meters | |
| 2) C. 5 meters | |
| 3) B. 2 meters | |
| 4) A. 1 meter | |
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4. 4. During maintenance, what is the main means of combating wood damage for wooden supports? |
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| 1) D. Measuring rotting depth with a megohmmeter | |
| 2) C. Installing repair couplings | |
| 3) B. Applying antiseptics to the support material | |
| 4) A. Tapping the support in dry weather | |
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5. 5. What is the primary disadvantage of wooden supports for overhead power transmission lines? |
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| 1) D. Cracking | |
| 2) B. Melting | |
| 3) C. Rotting | |
| 4) A. Corrosion | |
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6. 6. How is the condition of wooden supports assessed during dry and frost-free weather? |
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| 1) D. Checking with binoculars | |
| 2) C. Performing night inspections | |
| 3) A. By measuring insulation resistance | |
| 4) B. Tapping to establish rotting of the core | |
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7. 7. What is the minimum distance required from overhead lines to the ground according to the Rules of electrical installations? |
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| 1) D. 7 meters | |
| 2) B. 5 meters | |
| 3) C. 6 meters | |
| 4) A. 2 meters | |
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8. 8. What percentage of overhead line damage is attributed to insulator failures according to the text? |
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| 1) D. 40% | |
| 2) B. 20% | |
| 3) C. 30% | |
| 4) A. 10% | |
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9. 9. How is the rotting depth of wooden supports determined? |
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| 1) D. By night inspections | |
| 2) C. By piercing the support with fixation of force | |
| 3) B. By measuring with a megohmmeter | |
| 4) A. By visual inspection | |
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10. 10. What is the primary purpose of repair couplings in the context of overhead power transmission lines? |
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| 1) D. To prevent short circuits to the ground | |
| 2) C. To check the condition of insulators | |
| 3) A. To restore mechanical strength of wires | |
| 4) B. To measure insulation resistance | |
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11. 11. When is an extraordinary inspection of overhead power transmission lines typically carried out? |
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| 1) D. During day inspections | |
| 2) C. Annually | |
| 3) A. Monthly | |
| 4) B. After accidents and natural disasters | |
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12. 12. What is the main focus when inspecting reinforced concrete supports for overhead lines? |
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| 1) D. Checking the tension of braces | |
| 2) B. Identifying visible defects | |
| 3) C. Measuring insulation resistance | |
| 4) A. Monitoring insulator condition | |
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13. 13. What should be the minimum thickness of the protective wall of concrete for overhead line supports? |
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| 1) D. 15 mm | |
| 2) B. 8 mm | |
| 3) C. 10 mm | |
| 4) A. 5 mm | |
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14. 14. How is a broken insulator detected using the simplest method mentioned in the text? |
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| 1) D. By performing control inspections | |
| 2) C. By checking the presence of voltage on each element of the garland | |
| 3) B. By tapping the insulator with a metal rod | |
| 4) A. By measuring insulation resistance | |
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15. 15. What is the resistance threshold that each insulator should not fall below during insulation resistance measurements? |
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| 1) C. 300 MOhm | |
| 2) D. 400 MOhm | |
| 3) B. 200 MOhm | |
| 4) A. 100 MOhm | |
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16. 16. Which of the following parameters is used to measure the minimum leakage current that will cause the GFCI to trip? |
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| 1) C. Operating Voltage (Volts) | |
| 2) D. Conditional Short-Circuit Current Rating (Amps) | |
| 3) A. Rated Current (Amps) | |
| 4) B. Differential Current (mA) | |
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17. 17. When inspecting reinforced concrete supports, the main attention should be paid to: |
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| 1) D. Detecting the slope of the support | |
| 2) C. Checking the thickness of the protective wall of concrete | |
| 3) B. Identifying visible defects | |
| 4) A. Inspection of condition of supports | |
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18. 18. Which of these inspections is performed 1 time a year? |
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| 1) C. Control | |
| 2) D. Riding | |
| 3) A. Day | |
| 4) B. Night | |
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19. 19. Overhead line inspections are divided into ____and extraordinary. |
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| 1) D. Malfunction | |
| 2) B. Riding | |
| 3) C. Controlling | |
| 4) A. Periodic | |
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20. 20. What is the advantage of RCD? |
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| 1) D. None of them | |
| 2) C. Neutral wire dependency. | |
| 3) B. Multifunctionality. | |
| 4) A. Complex troubleshooting. | |
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21. 21. What is the rated current of GFCI? |
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| 1) C. None of the above | |
| 2) D. The medium current | |
| 3) B. The smallest current that GFCI will trip | |
| 4) A. The maximum current that GFCI can handle without tripping | |
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22. 22. The resistance of each insulator should not be less than ___MOhm. |
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| 1) C. 300 MOhm | |
| 2) D. 400 MOhm | |
| 3) B. 200 MOhm | |
| 4) A. 100 MOhm | |
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23. 23. An analysis of the operation of overhead power lines shows that about ___of overhead line damage is due to insulator failures. |
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| 1) D. 20% | |
| 2) B. 60% | |
| 3) C. 30% | |
| 4) A. 35% | |
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24. 24. Magnetizing current of __ power transformer |
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| 1) D. 5-600 kV | |
| 2) C. 4-500 kV | |
| 3) B. 6-500 kV | |
| 4) A. 7-700 kV | |
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25. 25. Neutral power transformers____kV |
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| 1) D. 80-160 kV | |
| 2) C. 220-380 kV | |
| 3) B. 60-110 kV | |
| 4) A. 110-220 kV | |
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26. 26. What is the purpose of a short circuit device in an electrical circuit? |
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| 1) D. To amplify electrical signals | |
| 2) C. To prevent excess current flow during a short circuit | |
| 3) B. To regulate voltage | |
| 4) A. To increase electrical resistance | |
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27. 27. How is a separator controlled? |
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| 1) D. By manual rotation | |
| 2) C. Through voice commands | |
| 3) B. By a SHPO drive | |
| 4) A. By a cooking timer | |
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28. 28. What is the function of disconnect switches in electric power systems? |
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| 1) C. Generation of electric power. | |
| 2) D. Distribution of heat. | |
| 3) B. Isolation and disconnection of equipment. | |
| 4) A. Transmission of electric power. | |
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29. 29. The duration of a time delay of AR depends on: |
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| 1) C. air gap | |
| 2) D. all of the above | |
| 3) B. nominal current of the device | |
| 4) A. voltage, cross-section and material of the wires | |
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30. 30. What is the AR time delay? |
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| 1) A. 0.2-0.5s | |
| 2) B. 0.2-0.4s | |
| 3) C. 0.2-0.3s | |
| 4) D. 0.1-0.3s | |
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31. 31. What is the primary function of an Automatic Transfer Switch (ATR) device? |
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| 1) D. Renewable energy generation | |
| 2) B. Automatic reserve input | |
| 3) C. Voltage regulation | |
| 4) A. Energy conservation | |
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32. 32. Which of the following can serve as a backup power source in an ATR system? |
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| 1) D. Diesel generator (DGU) | |
| 2) C. Geothermal energy | |
| 3) B. Natural gas supply | |
| 4) A. Solar panels | |
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33. 33. How many independent power sources do first-category power consumers typically have? |
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| 1) D. Four | |
| 2) C. Three | |
| 3) B. Two | |
| 4) A. One | |
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34. 34. In the special first category, how many mutually redundant power sources are required for consumers? |
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| 1) D. Four | |
| 2) C. Three | |
| 3) A. One | |
| 4) B. Two | |
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35. 35. What is the primary purpose of an Automatic Transfer Switch (ATS) device? |
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| 1) D. Renewable energy generation | |
| 2) C. Voltage regulation | |
| 3) B. Uninterrupted power supply | |
| 4) A. Energy conservation | |
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36. 36. How does an ATS system respond to disruptions in the main power line? |
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| 1) D. Initiates a shutdown | |
| 2) C. Quickly switches to the backup source | |
| 3) B. Monitors without taking action | |
| 4) A. Activates repeated switching | |
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37. 37. When should the disconnection of the main grid occur in relation to connecting the backup line in an ATS system? |
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| 1) D. It doesn't matter | |
| 2) C. Before connecting the backup line | |
| 3) B. Simultaneously | |
| 4) A. After connecting the backup line | |
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38. 38. What is a crucial feature regarding the action of an ATS device in the case of the same fault? |
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| 1) D. Ignoring faults for uninterrupted supply | |
| 2) C. One-time event for the same fault | |
| 3) A. Repeated activations for the same fault | |
| 4) B. Slow response for fault conditions | |
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39. 39. What conditions can trigger the automation system to command a change in the power source for an ATS device? |
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| 1) D. Noise levels exceeding a threshold | |
| 2) C. Wind speed variations | |
| 3) B. Deviations in working voltage parameters | |
| 4) A. Changes in temperature | |
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40. 40. Why is it essential for the ATS device to check for unresolved faults on the protected section before switching to a backup source? |
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| 1) D. To speed up the switching process | |
| 2) C. To increase backup source usage | |
| 3) A. To save energy | |
| 4) B. To prevent dangerous situations | |
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41. 41. Under what conditions will the ATS device return to the primary input when using two equivalent inputs? |
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| 1) D. When unresolved faults are present on the backup line. | |
| 2) C. When electrical current parameters on the primary input are restored | |
| 3) B. Only during financial losses | |
| 4) A. Whenever there is a deviation from specified parameters | |
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42. 42. What are the two main components of an ATS device from a technical perspective? |
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| 1) D. Mechanical and Protective | |
| 2) B. Decision-Making and Signaling | |
| 3) C. Logical and Switching | |
| 4) A. Logical and Operational | |
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43. 43. What is the task of the measuring section in the ATS device? |
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| 1) D. Ensuring redundancy in power supply | |
| 2) C. Constantly monitoring input parameters | |
| 3) B. Performing mechanical functions | |
| 4) A. Making necessary connections | |
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44. 44. What does the logical controller in the ATS device include for decision-making? |
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| 1) D. Sectional switch | |
| 2) C. Adjustable time delay setting | |
| 3) B. Measuring devices | |
| 4) A. Two-position relay | |
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45. 45. What is the purpose of the indicator (signaling) part in the ATS device? |
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| 1) D. Setting upper and lower limits for working voltage | |
| 2) C. Informing about changes and faults in operation | |
| 3) A. Performing mechanical functions | |
| 4) B. Making necessary connections | |
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46. 46. How is the power section in the ATS device assembled? |
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| 1) D. Using logical controllers | |
| 2) C. Using contactors or automatic circuit breakers | |
| 3) A. Using measuring devices | |
| 4) B. Using adjustable time delay settings | |
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47. 47. What is the key feature of a two-input ATS scheme? |
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| 1) D. Activation through sectional switches | |
| 2) C. Priority given to the second input | |
| 3) B. Equivalence between inputs | |
| 4) A. Both inputs being activated simultaneously | |
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48. 48. How does a two-input ATS scheme operate in normal conditions? |
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| 1) B. The second input always has priority | |
| 2) C. Both inputs are activated simultaneously | |
| 3) D. Activation is controlled by measuring devices | |
| 4) A. The first input always has priority | |
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49. 49. When is a two-input ATS scheme with sectioning used? |
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| 1) D. In the absence of measuring devices | |
| 2) C. During faults in the main power grid | |
| 3) B. When power distribution is divided between two different inputs | |
| 4) A. In normal operating conditions | |
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50. 50. What ensures that both inputs are equivalent in a two-input ATS scheme with sectioning? |
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| 1) D. Measuring devices | |
| 2) B. Sectional switch | |
| 3) C. Priority settings in the logical controller | |
| 4) A. Adjustable time delay setting | |
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51. 51. What does the sectional switch provide in a two-input ATS scheme with sectioning? |
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| 1) C. Power to the de-energized section from the other input | |
| 2) D. Activation of measuring devices in case of faults | |
| 3) B. Redundancy in the logical controller | |
| 4) A. Continuous power supply to both sections | |
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52. 52. Why is cooling essential for transformers? |
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| 1) C. To dissipate excess heat generated | |
| 2) D. To improve insulation quality | |
| 3) B. To prevent dust accumulation | |
| 4) A. To reduce noise levels | |
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53. 53. Which type of transformers are suitable for the Air Natural (AN) cooling method? |
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| 1) D. Transformers up to 3 MVA | |
| 2) C. Transformers rated above 15 MVA | |
| 3) B. Dry type transformers | |
| 4) A. Oil-immersed transformers | |
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54. 54. What is the purpose of the Air Blast cooling method for transformers? |
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| 1) D. To cool transformers rated up to 15 MVA | |
| 2) C. To prevent oil contamination | |
| 3) B. To dissipate heat using forced air | |
| 4) A. To cool by natural air flow | |
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55. 55. Which cooling method is used for oil-immersed transformers up to about 30 MVA, relying on natural convection and conduction? |
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| 1) D. Oil Natural Air Natural (ONAN) | |
| 2) A. Oil Forced Water Forced (OFWF) | |
| 3) B. Oil Natural Air Forced (ONAF) | |
| 4) C. Oil Forced Air Forced (OFAF) | |
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56. 56. How is the heat dissipation improved in the Oil Forced Air Forced (OFAF) cooling method? |
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| 1) D. By applying forced oil flow | |
| 2) B. By using forced air on the dissipating surface | |
| 3) C. By natural convection | |
| 4) A. By applying forced water flow | |
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57. 57. Which cooling method is generally used for large transformers up to about 60 MVA and employs forced air with automatic starting arrangements? |
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| 1) D. Oil Forced Air Forced (OFAF) | |
| 2) B. Air Blast | |
| 3) C. Oil Natural Air Forced (ONAF) | |
| 4) A. Air Natural (AN) | |
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58. 58. What is the distinguishing feature of the Oil Forced Water Forced (OFWF) cooling method? |
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| 1) D. Employment of automatic starting arrangements | |
| 2) B. Circulation of oil through heat exchangers | |
| 3) C. Dissipation of heat through natural convection | |
| 4) A. Use of forced water flow for heat dissipation | |
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59. 59. Which cooling method is applied in very large transformers with ratings of several hundreds MVA? |
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| 1) D. Oil Natural Air Forced (ONAF) | |
| 2) C. Oil Forced Water Forced (OFWF) | |
| 3) A. Air Natural Or Self Air Cooled | |
| 4) B. Oil Forced Air Forced (OFAF) | |
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60. 60. What is the principle behind the Oil Natural Air Natural (ONAN) cooling method for oil-immersed transformers? |
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| 1) D. Natural convection of heated oil | |
| 2) C. Forced oil flow through heat exchangers | |
| 3) A. Forced air flow through the radiator | |
| 4) B. Conduction of heat through oil | |
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61. 61. When is the Oil Forced Air Forced (OFAF) cooling method typically provided for transformers? |
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| 1) D. For transformers up to about 30 MVA | |
| 2) C. For transformers rated more than 3 MVA | |
| 3) B. For higher rating transformers at substations or power stations | |
| 4) A. For transformers up to 3 MVA | |
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62. 62. What crucial roles do electrical substations play in the power grid? |
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| 1) D. Dangerous mess of wires | |
| 2) C. Essential functions in electrical distribution | |
| 3) A. Decoration | |
| 4) B. Chaotic arrangement | |
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63. 63. What is the primary function of a substation in terms of voltage levels? |
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| 1) C. Improving grid stability | |
| 2) D. Avoiding shutdowns in the entire substation | |
| 3) A. Power factor correction | |
| 4) B. Changing nature of supply voltage | |
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64. 64. How are substations classified based on voltage levels? |
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| 1) A. By geographical location | |
| 2) B. By construction features | |
| 3) C. By operational challenges | |
| 4) D. By voltage ranges | |
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65. 65. What voltage range is typically associated with Low Voltage (LV) Substations? |
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| 1) D. 2.4KV - 69KV | |
| 2) C. 0.24KV - 0.6 KV | |
| 3) B. 800KV - 1,100KV | |
| 4) A. 115KV - 765 kV | |
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66. 66. What type of substations allow switching between power lines without altering transmitted voltages? |
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| 1) D. Converting Substations | |
| 2) B. Collecting Substations | |
| 3) C. Switching Substations | |
| 4) A. Transformer Substations | |
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67. 67. Where are Power Factor Substations usually located to compensate for power losses during transmission? |
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| 1) D. At the secondary side of transmission lines | |
| 2) C. In residential areas | |
| 3) B. Near load centers | |
| 4) A. Near generating stations | |
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68. 68. What is the purpose of Mobile substations? |
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| 1) D. Industrial power supply | |
| 2) C. Power factor correction | |
| 3) B. Easy maintenance and protection from blackouts | |
| 4) A. Permanent electrical supply | |
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69. 69. Where are Industrial Substations commonly used? |
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| 1) D. Underground mines | |
| 2) C. Dedicated consumers like industries | |
| 3) A. Residential areas | |
| 4) B. Large-scale constructions | |
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70. 70. What characterizes Indoor Substations? |
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| 1) D. Surface-mounted transformers | |
| 2) B. Large area clearance between live conductors | |
| 3) C. Equipment installed within a building | |
| 4) A. Equipment exposed to hazardous chemicals | |
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71. 71. What is a characteristic of Outdoor Substations? |
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| 1) D. Equipment located outdoors with large area clearance | |
| 2) B. Equipment exposed to hazardous chemicals | |
| 3) C. Small area clearance between live conductors | |
| 4) A. Equipment located indoors | |
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72. 72. What factors determine the selection of the type of transformer? |
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| 1) A. Transformer color | |
| 2) B. Transformer weight | |
| 3) C. Location of the substation | |
| 4) D. Transformer brand | |
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73. 73. In terms of kVA, what size range is preferred for liquid-filled transformers for a 12.47kV/480V system? |
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| 1) D. 1000-5000 kVA | |
| 2) C. 750-3750 kVA | |
| 3) B. 500-1000 kVA | |
| 4) A. 0-500 kVA | |
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74. 74. What is the purpose of an Instrument Transformer? |
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| 1) C. To transform current from a higher value to a lower value | |
| 2) A. To transform voltage from a higher value to a lower value | |
| 3) D. To transform voltage from a lower value to a higher value | |
| 4) B. To transform current from a lower value to a higher value | |
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75. 75. What are the two types of Instrument Transformers mentioned in the text? |
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| 1) D. Power Transformer and Distribution Transformer | |
| 2) A. Voltage Transformer and Power Transformer | |
| 3) B. Current Transformer and Power Transformer | |
| 4) C. Voltage Transformer and Current Transformer | |
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76. 76. What does Switchgear refer to in the context of electrical substations? |
|
| 1) D. A type of transformer | |
| 2) C. A gear system for manual power transmission | |
| 3) B. Collection of devices for controlling and isolating electrical equipment | |
| 4) A. Collection of snacks for substation workers | |
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77. 77. What is the role of Monitoring Equipment in a substation? |
|
| 1) D. Monitoring and selecting protective devices | |
| 2) C. Controlling the flow of electricity | |
| 3) A. Providing emergency lighting | |
| 4) B. Designing protective relays | |
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78. 78. What is the primary function of a Bus-Bar in an electrical power substation? |
|
| 1) C. Acting as a protective relay | |
| 2) D. Transforming voltage levels | |
| 3) B. Carrying electrical current with many connections | |
| 4) A. Providing emergency power | |
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79. 79. What is the purpose of Batteries in electric power stations and substations? |
|
| 1) C. Powering industrial substations | |
| 2) D. Operating and controlling protective relay systems | |
| 3) B. Supplying power to residential consumers | |
| 4) A. Providing emergency power during blackouts | |
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80. 80. What types of batteries are commonly used in power stations and substations? |
|
| 1) D. Lithium and Nickel-metal hydride batteries | |
| 2) C. Lead acid and Nickel-metal hydride batteries | |
| 3) A. Alkaline and Lithium batteries | |
| 4) B. Lead acid and Alkaline batteries | |
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81. 81. What are Indicating and Metering Instruments used for in substations? |
|
| 1) D. Measuring atmospheric pressure | |
| 2) C. Monitoring current and power loads | |
| 3) A. Making coffee for substation workers | |
| 4) B. Controlling transformers | |
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82. 82. How is a Circuit Breaker characterized in its ability to handle current flow under normal and fault conditions? |
|
| 1) C. Power factor correction device | |
| 2) D. Instrument transformer | |
| 3) B. Voltage transformer | |
| 4) A. Mechanical isolating device | |
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83. 83. What is the purpose of a Lightning Arrestor in a substation? |
|
| 1) D. Operating circuit breakers | |
| 2) A. Diverting surges to the ground and protecting equipment | |
| 3) C. Regulating voltage levels | |
| 4) B. Generating electrical surges | |
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84. 84. What do High-Voltage Fuses primarily protect in substations? |
|
| 1) A. Batteries | |
| 2) B. Insulators | |
| 3) C. Power transformers | |
| 4) D. Bus-Bars | |
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85. 85. What is the role of a Relay in a power system? |
|
| 1) D. Isolating power transformers | |
| 2) C. Providing emergency lighting | |
| 3) A. Producing electrical surges | |
| 4) B. Protecting equipment against abnormal conditions like faults | |
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86. 86. What is the purpose of the "point check" in the installation of power transformers? |
|
| 1) D. To carry out the stabilizing process | |
| 2) C. To check the equipment type, size, and other information | |
| 3) A. To verify the working performance | |
| 4) B. To transfer the transformer to the construction site | |
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87. 87. What is the secondary handling of the transformer? |
|
| 1) B. Stabilizing the transformer | |
| 2) C. Transferring the transformer from the depot to the construction site | |
| 3) D. Filling the transformer with oil | |
| 4) A. Fixing the main parts to the construction site | |
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88. 88. When is the installation of transformer accessories carried out? |
|
| 1) C. During the secondary handling | |
| 2) D. During the point check | |
| 3) B. After stabilizing the transformer | |
| 4) A. Before stabilizing the transformer | |
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89. 89. What is the purpose of fuse disconnectors with a voltage above 1 kV in distribution networks? |
|
| 1) D. To improve internet connectivity | |
| 2) C. To regulate electrical consumption | |
| 3) A. To enhance communication systems | |
| 4) B. To protect loads from voltage surges, overloads, and short circuits | |
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90. 90. What is the role of the fusible insert in a fuse disconnector? |
|
| 1) B. Electrical insulation | |
| 2) C. Carrying the rated current and interrupting the circuit in case of overload | |
| 3) D. Quenching arcs during fuse operation | |
| 4) A. Mechanical support | |
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91. 91. How is circuit interruption achieved in a fuse disconnector? |
|
| 1) D. By using arc-quenching material | |
| 2) C. By increasing the rated breaking capacity | |
| 3) B. By melting the fusible insert | |
| 4) A. By tightening contact pressure | |
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92. 92. What is the purpose of the cartridge in a fuse disconnector? |
|
| 1) D. To prevent voltage surges | |
| 2) C. To provide mechanical support and electrical insulation | |
| 3) B. To interrupt the electrical circuit | |
| 4) A. To carry the rated current | |
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93. 93. What is the role of arc-quenching material in a fuse disconnector? |
|
| 1) C. To prevent sustained arcing and protect equipment | |
| 2) D. To provide mechanical support | |
| 3) B. To interrupt the electrical circuit | |
| 4) A. To carry the rated current | |
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94. 94. Where is the trip indicator typically mounted on a fuse disconnector? |
|
| 1) D. Near the contacts | |
| 2) C. On the top cover of the fuse tube | |
| 3) B. On the fusible insert | |
| 4) A. Inside the cartridge | |
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95. 95. What is the purpose of testing high-voltage fuses? |
|
| 1) D. To reduce the resistance of the fusible insert | |
| 2) C. To assess the condition of the devices and ensure compliance with specifications | |
| 3) A. To increase the rated breaking capacity | |
| 4) B. To improve fire safety | |
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96. 96. What equipment is used for testing high-voltage fuses to assess their condition? |
|
| 1) D. Infrared cameras | |
| 2) A. Oscilloscopes | |
| 3) B. Megohmmeters and resistance meters | |
| 4) C. Power drills | |
|
97. 97. What determines the operability of switching devices in high-voltage fuses? |
|
| 1) C. The material of the fusible insert | |
| 2) D. The size of the arc-quenching material | |
| 3) A. The color of the fuse tube | |
| 4) B. Nominal voltages and tripping currents | |
|
98. 98. Which equipment is used for electrical tests on high-voltage fuses? |
|
| 1) C. E6-32 | |
| 2) D. Both A and B | |
| 3) B. IFN-200 | |
| 4) A. ETL-35K | |
|
99. 99. In what sequence are measurements carried out during electrical tests on high-voltage fuses? |
|
| 1) D. Visual inspection, high-voltage testing, resistance measurement | |
| 2) C. Resistance testing, visual inspection, contact pressure verification | |
| 3) B. Nominal voltage measurement, resistance testing, tripping current assessment | |
| 4) A. Visual inspection, contact pressure verification, arc-quenching medium check | |
|
100. 100. What is the primary parameter determining the ability to disconnect the circuit in high-voltage fuses? |
|
| 1) B. Rated breaking capacity | |
| 2) C. Nominal voltage | |
| 3) D. Contact pressure | |
| 4) A. Resistance of the fusible insert | |
|
101. 101. What is the purpose of the mobile laboratory ETL-35K in testing high-voltage fuses? |
|
| 1) D. To check the integrity of the insert | |
| 2) C. To supply high voltage for testing | |
| 3) A. To measure contact pressure | |
| 4) B. To assess the operability of the fuse disconnector | |
|
102. 102. How is the integrity of the insert checked during electrical tests? |
|
| 1) C. By checking the arc-quenching medium | |
| 2) D. By using a megohmmeter | |
| 3) B. By visual inspection | |
| 4) A. By measuring the resistance | |
|
103. 103. What does the trip indicator on a fuse disconnector signify? |
|
| 1) C. The presence of sustained arcing | |
| 2) D. The necessity of contact pressure verification | |
| 3) A. The need for visual inspection | |
| 4) B. The operability of the fuse | |
|
104. 104. What is the primary purpose of circuit breakers in electrical distribution networks? |
|
| 1) D. To improve fire safety | |
| 2) A. To increase current flow | |
| 3) B. To protect against voltage surges | |
| 4) C. To regulate electrical consumption | |
|
105. 105. What components in a circuit breaker provide protective functions and open the contacts when the current exceeds the nominal value? |
|
| 1) D. Arc-quenching material | |
| 2) A. Cartridges | |
| 3) B. Releases | |
| 4) C. Fusible inserts | |
|
106. 106. What two types of releases are mentioned as providing protective functions in circuit breakers? |
|
| 1) D. Mechanical and thermal | |
| 2) C. Fusible and semiconductor | |
| 3) B. Electromagnetic and arc-quenching | |
| 4) A. Thermal and magnetic | |
|
107. 107. What is the measured parameter during the testing of circuit breakers' operation? |
|
| 1) B. Tripping time | |
| 2) C. Current flow | |
| 3) D. Resistance value | |
| 4) A. Voltage magnitude | |
|
108. 108. Why is it necessary to test circuit breakers after short-circuit events? |
|
| 1) D. To identify counterfeit products | |
| 2) C. To ensure the safety of personnel and equipment | |
| 3) B. To assess the wear on the circuit breaker | |
| 4) A. To check the plastic quality | |
|
109. 109. What conditions indicate a successful test of a circuit breaker after a short-circuit event? |
|
| 1) D. Leakage of insulating compound, weakened connections, and rough plastic | |
| 2) C. Smooth plastic, easily scratched barcode, and damaged casing | |
| 3) B. No critical wear, unchanged position of contacts, and intact casing | |
| 4) A. Critical wear, changed position of contacts, and damaged casing | |
|
110. 110. How can one identify a counterfeit ABB circuit breaker according to the provided information? |
|
| 1) D. Regular ink barcode and rough plastic | |
| 2) C. Matte plastic and glossy casing | |
| 3) B. Smooth plastic and intact casing | |
| 4) A. Laser-printed barcode and rough plastic | |
|
111. 111. What is the purpose of testing circuit breakers with voltages up to 1000 V? |
|
| 1) D. To check the plastic quality | |
| 2) A. To improve fire safety | |
| 3) B. To assess wear on the circuit breaker | |
| 4) C. To measure insulation resistance and ensure safety | |
|
112. 112. What is the acceptable tripping time for distribution circuits and circuits supplying mobile electrical equipment, given a certain resistance condition? |
|
| 1) D. Up to 10 seconds | |
| 2) A. Up to 1 second | |
| 3) B. Up to 0.4 seconds | |
| 4) C. Up to 5 seconds | |
|
113. 113. When testing circuit breakers, what should be the insulation resistance between the apparatus's pole and ground? |
|
| 1) C. At least 1 MOhm | |
| 2) D. At least 0.5 MOhm | |
| 3) B. Less than 0.5 MOhm | |
| 4) A. Less than 1 MOhm | |
|
114. 114. What is the permissible insulation resistance value during high voltage testing at 1000 V for 1 minute? |
|
| 1) D. 1 MOhm for each phase | |
| 2) C. 2500 V | |
| 3) B. 1 MOhm | |
| 4) A. 500 V | |
|
115. 115. How are semiconductor trip units typically subjected to testing regarding the protection block current? |
|
| 1) D. Tenfold | |
| 2) C. Sixfold | |
| 3) B. Fourfold | |
| 4) A. Onefold | |
|
116. 116. What is the purpose of testing the operation of circuit breakers at nominal and reduced voltage? |
|
| 1) D. To ensure correct and safe operation | |
| 2) C. To assess wear on the circuit breaker | |
| 3) B. To ensure proper installation | |
| 4) A. To identify counterfeit products | |
|
117. 117. How often should the measurement of insulation resistance be performed, and what is the minimum value specified? |
|
| 1) C. Once every 6 months, 0.5 Mohm | |
| 2) D. Once every 6 years, 0.5 MOhm | |
| 3) B. Once every 6 years, 1 MOhm | |
| 4) A. Once every 6 months, 1 MOhm | |
|
118. 118. What precautions should be taken when connecting the input terminals of the devices being tested to the current-carrying circuit? |
|
| 1) D. Disassemble the circuit breaker for better access | |
| 2) B. Ensure the presence of voltage | |
| 3) C. Use insulating overshoes, gloves, and insulated tools | |
| 4) A. None, as it is safe | |
|
119. 119. How is the insulation resistance of moving and guiding parts made of organic materials measured in oil switches with voltage up to 10 kV? |
|
| 1) D. By measuring DC resistance with a DC bridge | |
| 2) C. Through the ammeter-voltmeter method | |
| 3) B. With a 2500 V megaohmmeter | |
| 4) A. Using a high-voltage test transformer | |
|
120. 120. What devices are used to measure the DC resistance of switch poles in oil switches with an accuracy of 0.001 ohms? |
|
| 1) C. Ammeter-voltmeter method | |
| 2) D. DC bridges P333 | |
| 3) A. Megaohmmeters | |
| 4) B. Micro-meters of the F4104-M1 type | |
|
121. 121. How is the high-voltage insulation testing carried out during major repairs of oil switches? |
|
| 1) D. Disconnecting the test unit after maintaining the voltage for 1 minute | |
| 2) C. Gradually raising the voltage to the required level | |
| 3) A. By measuring the resistance of main contacts | |
| 4) B. Using a 2500 V megaohmmeter | |
|
122. 122. When is the insulation resistance measured on oil switches with pull-out elements (switch trolleys)? |
|
| 1) B. On a disconnected switch during breaking | |
| 2) C. On a fully withdrawn switch with disconnected secondary circuits | |
| 3) D. During major repairs of switches | |
| 4) A. On a completely deflated and disconnected switch | |
|
123. 123. How is the resistance measurement of the full pole of the pull-out element performed? |
|
| 1) C. With a 2500 V megaohmmeter | |
| 2) D. Gradually raising the voltage to the required level | |
| 3) A. Using microohmmeters or DC bridges | |
| 4) B. Through the ammeter-voltmeter method | |
|
124. 124. What is the test voltage for secondary circuits and control electromagnets during insulation testing, provided these devices are designed for at least 60V? |
|
| 1) C. 1 kV | |
| 2) D. 60 V | |
| 3) A. 2500 V | |
| 4) B. 10 kV | |
|
125. 125. How is the condition of the contact system of the switch evaluated during testing? |
|
| 1) D. By measuring the resistance of main contacts | |
| 2) A. By measuring insulation resistance | |
| 3) B. By comparing measured resistance with normalized values | |
| 4) C. Using microohmmeters | |
|
126. 126. What is the purpose of gradually raising the voltage during high-voltage insulation testing of oil switches? |
|
| 1) D. To use DC bridges | |
| 2) B. To decrease the voltage after maintaining for 1 minute | |
| 3) C. To perform the ammeter-voltmeter method | |
| 4) A. To ensure reliable contact with the measured circuit | |
|
127. 127. How often should the insulation resistance measurement be performed on oil switches 6-10 kV during repair work in the cells? |
|
| 1) C. Once every month | |
| 2) D. Once every 2 years | |
| 3) B. Once every 6 years | |
| 4) A. Once every 6 months | |
|
128. 128. What is used to measure the insulation resistance of secondary circuits and control electromagnets when these devices are disconnected? |
|
| 1) C. DC bridges P333 | |
| 2) D. Megaohmmeters at 2500 V | |
| 3) B. Microohmmeters | |
| 4) A. High-voltage test transformers | |
|
129. 129. What is the initial step in testing power transformers, and what components are inspected externally? |
|
| 1) D. Checking dielectric losses; moisture content | |
| 2) C. Phasing of the transformer; voltage measurements | |
| 3) B. External inspection; seals, oil quantity, grounding, etc. | |
| 4) A. Measuring insulation resistance; windings and oil | |
|
130. 130. Why is it essential to dry or heat a transformer exposed to moisture before energizing? |
|
| 1) D. To measure dielectric losses | |
| 2) C. To decrease capacitance | |
| 3) A. To reduce the oil quantity | |
| 4) B. To meet insulation standards | |
|
131. 131. When should the insulation characteristics of dry transformers be measured after oil filling? |
|
| 1) D. During the oil sampling process | |
| 2) C. When the temperature is below 10°C | |
| 3) B. At least 12 hours after oil filling | |
| 4) A. Immediately after oil filling | |
|
132. 132. What is the operating voltage of the megohmmeter used to measure the insulation resistance of transformer windings? |
|
| 1) D. 5000 V | |
| 2) B. 220 V | |
| 3) C. 2500 V | |
| 4) A. 10 V | |
|
133. 133. How is the tangent of the angle of dielectric losses measured for oil-filled transformers? |
|
| 1) D. Using an alternating current bridge | |
| 2) C. At 220 V | |
| 3) B. At a voltage exceeding 2/3 of the specified test voltage | |
| 4) A. At the manufacturer's specified test voltage | |
|
134. 134. Why are capacitance measurements performed at frequencies of 2 Hz and 50 Hz during electrical testing? |
|
| 1) D. To check the correctness of phasing | |
| 2) B. To determine the moisture content | |
| 3) C. To measure dielectric losses | |
| 4) A. To check winding connections | |
|
135. 135. How is the correctness of winding connections in a transformer determined? |
|
| 1) C. Measuring capacitance | |
| 2) D. Determining the transformation ratio with two voltmeters | |
| 3) B. Phasing with signal lamps | |
| 4) A. Using a wattmeter | |
|
136. 136. What do current and no-load losses characterize in a transformer? |
|
| 1) D. Dielectric losses | |
| 2) C. Moisture content | |
| 3) B. Hysteresis and eddy current losses | |
| 4) A. Insulation resistance | |
|
137. 137. How is the phasing of a transformer performed, and what is the verification method? |
|
| 1) D. Applying a high voltage test; recording in the protocol | |
| 2) C. Phasemeter or direct current method; voltmeter or indicators | |
| 3) B. Measuring capacitance; special indicators | |
| 4) A. Using a voltmeter; checking dielectric losses | |
|
138. 138. What is the final step after completing the testing of a power transformer, and when is the transformer put into operation? |
|
| 1) D. Conducting a high voltage test on the oil; ensuring correct phasing | |
| 2) C. Checking winding connections; measuring capacitance | |
| 3) B. Recording data in the protocol; conforming to standards | |
| 4) A. Measuring the tangent of the angle of losses | |
|
139. 139. What information is crucial to include on the Low Voltage Circuit Breaker Data Sheet? |
|
| 1) D. Electrically operated breaker specifications | |
| 2) C. Job number, nameplate data, and test results | |
| 3) A. Megger insulation test results | |
| 4) B. Weather conditions during testing | |
|
140. 140. What is the satisfactory test result for the Megger insulation test on a rebuilt 480V circuit breaker? |
|
| 1) D. 480 mega ohms | |
| 2) C. 200 mega ohms | |
| 3) A. 50 mega ohms | |
| 4) B. 100 mega ohms or higher | |
|
141. 141. Why is the Contact Resistance Test (Ductor Test) performed on low voltage circuit breakers? |
|
| 1) D. To check under voltage devices | |
| 2) C. To ensure solid and equal contact surfaces | |
| 3) B. To verify the operation of the Y relay | |
| 4) A. To test the blown fuse device | |
|
142. 142. How should electrically operated circuit breakers be tested, specifically regarding the charging motor and tripping mechanism? |
|
| 1) D. By tripping the circuit breaker from the primary disconnects | |
| 2) B. By closing the circuit breaker from the primary disconnects | |
| 3) C. By applying voltage at the secondary disconnects | |
| 4) A. By applying voltage at the primary disconnects | |
|
143. 143. What is the purpose of high current injection testing on circuit breakers? |
|
| 1) C. To test the blown fuse device | |
| 2) D. To check the reliability of the trip units | |
| 3) A. To verify operation of the Y relay | |
| 4) B. To ensure solid and equal contact surfaces | |
|
144. 144. What percentage of the breaker's normal load rating is typically used for testing a circuit breaker's long-time function during high current injection testing? |
|
| 1) D. 300% | |
| 2) B. 100% | |
| 3) C. 150% | |
| 4) A. 50% | |
|
145. 145. What information should be recorded on the Low Voltage Circuit Breaker Data Sheet during high current injection testing? |
|
| 1) D. Contact resistance test results for each phase | |
| 2) A. Weather conditions during testing | |
| 3) C. Electrically operated breaker specifications | |
| 4) B. Manufacturer's curves for the specific circuit breaker | |
|
146. 146. What is the first step in the installation of power transformers, and who participates in the point check of the equipment? |
|
| 1) D. Installing transformer accessories | |
| 2) A. Stabilizing the transformer | |
| 3) B. Secondary handling | |
| 4) C. Joint check by installation, supply, and construction companies | |
|
147. 147. What does the secondary handling of the transformer involve, and what tools are necessary for this step? |
|
| 1) D. Testing the working performance of the transformer; oil filter | |
| 2) C. Transfer from the depot to the construction site; specialized handling tools | |
| 3) B. Fixing main parts to the construction site; construction drawings | |
| 4) A. Filling the transformer with oil; specialized handling tools | |
|
148. 148. When is the stabilizing step of the transformer carried out, and what does it involve? |
|
| 1) D. After installing accessories; completing overall assembly | |
| 2) A. Before the point check; checking equipment type and size | |
| 3) B. After secondary handling; fixing main parts to the construction site | |
| 4) C. Before secondary handling; transferring the transformer from the depot | |
|
149. 149. What are the last three steps of transformer installation mainly focused on, and what do they aim to achieve? |
|
| 1) D. Stabilizing; transferring to the construction site; completing overall assembly | |
| 2) A. Secondary handling; stabilizing; filling with oil | |
| 3) B. Installing accessories; filtering transformer oil; ensuring normal operation | |
| 4) C. Test steps; checking working performance; guaranteeing normal operation | |
|
150. 150. Why is filtering transformer oil important, and what issues can arise if it is not done correctly? |
|
| 1) B. To ensure the quality of the installation; avoiding personal injuries | |
| 2) C. To guarantee normal operation; preventing impurities and density errors | |
| 3) D. To avoid fires during installation; ensuring a closed space for filtering | |
| 4) A. To prevent debris from falling into the tank; impact on the power transformer system | |
|
151. 151. What is the primary concern during the installation of power transformers, and what precautionary measures should be taken? |
|
| 1) D. Ensuring the correct density of oil; monitoring installation site in real-time | |
| 2) B. Personal injuries; assign additional personnel for supervision | |
| 3) C. Filtering transformer oil; using a specific oil filter | |
| 4) A. Falling debris; use of advanced air filters | |
|
152. 152. Why is fire prevention crucial during the installation of power transformers, and what precautionary measures are recommended? |
|
| 1) D. To avoid impurities in the oil; use of advanced air filters | |
| 2) C. To ensure the correct density of oil; deployment of oil proportioning | |
| 3) B. To avoid fires due to flammable liquids; preparation of fire extinguishing equipment | |
| 4) A. To prevent personal injuries; use of specialized handling tools | |
|
153. 153. What can happen if debris falls into the tank during the installation of power transformers, and how is this issue addressed in the market? |
|
| 1) C. Paralysis of the transformer; preparation of fire extinguishing equipment | |
| 2) D. Threat to staff's life; assignment of additional personnel for supervision | |
| 3) B. Contamination of the oil; real-time monitoring at the installation site | |
| 4) A. Impact on the power transformer system; use of advanced air filters | |
|
154. 154. What is one potential cause of personal injuries during the installation of power transformers, and how can it be prevented? |
|
| 1) D. Filtering transformer oil; assignment of additional personnel for supervision | |
| 2) A. Leakage of electricity; use of advanced air filters | |
| 3) B. Falling debris; preparation of fire extinguishing equipment | |
| 4) C. Fires due to flammable liquids; real-time monitoring at the installation site | |
|
155. 155. What is the role of additional personnel during the installation of power transformers, and why are they assigned to the site? |
|
| 1) D. To filter transformer oil; use specialized handling tools | |
| 2) C. To test the working performance; check for impurities in the oil | |
| 3) B. To supervise the site; react immediately to incidents and guarantee normal installation | |
| 4) A. To complete overall assembly; ensure normal operation | |
|
156. 156. What is emphasized as a key element in maintaining the efficiency and prolonging the lifetime of electric motors? |
|
| 1) A. Major repairs | |
| 2) B. Predictive maintenance | |
| 3) C. Minor checks and maintenance | |
| 4) D. Reactive maintenance | |
|
157. 157. Which type of electric motor is mentioned as the most commonly used in the article, and what contributes to its lower maintenance requirements? |
|
| 1) A. Synchronous motors; advanced features | |
| 2) B. DC motors; simplicity | |
| 3) C. Stepper motors; precision | |
| 4) D. Induction motors; simple and rugged construction | |
|
158. 158. Why are induction motors considered almost maintenance-free, and what can be traced back as the cause of most induction motor failures? |
|
| 1) C. They undergo major repairs regularly; voltage variations | |
| 2) D. They can be eliminated by simple and minor checks; bad ventilation, loosened terminals, and over-temperature | |
| 3) A. They require frequent checks; misalignment issues | |
| 4) B. They have complex constructions; lack of lubricants | |
|
159. 159. What are some reasons mentioned in the article that can lead to motor failure if not addressed through regular checks? |
|
| 1) B. Loosened terminals and preventive maintenance | |
| 2) C. Bad ventilation, over-temperature, and misalignment | |
| 3) D. Sufficient cooling and predictive maintenance | |
| 4) A. Predictive maintenance and over-temperature | |
|
160. 160. Why is reactive maintenance considered the most costly, and what does it involve? |
|
| 1) D. It involves major repairs; repairs done after facing a failure | |
| 2) B. It aims to keep the motor running at the highest efficiency; minor maintenance | |
| 3) C. It involves predictive maintenance; repairs done before facing a failure | |
| 4) A. It prevents failures; repairs done after facing a failure | |
|
161. 161. What is the importance of motor cooling, and what problems can high temperatures cause for electric motors? |
|
| 1) D. It leads to noise analysis problems; motor windings failure | |
| 2) C. It increases motor efficiency; bad ventilation | |
| 3) B. It ensures sufficient cooling; bearing or windings failure | |
| 4) A. It prevents misalignment; over-temperature | |
|
162. 162. What is the significance of maintaining the cleanliness of motor ventilation paths, and how can it vary based on the environment? |
|
| 1) D. It ensures bad ventilation; importance varies with dust concentration | |
| 2) C. It reduces humidity; less cleaning in clean areas | |
| 3) A. It avoids misalignment; constant cleaning is required | |
| 4) B. It prevents noise analysis problems; frequent cleaning in dusty areas | |
|
163. 163. What are some minor troubles highlighted in the article that can be fatal to electric motors if not handled properly? |
|
| 1) C. Voltage variations and under-voltages | |
| 2) D. Motor cooling, cleanliness of ventilation paths, and loosened terminals | |
| 3) A. Noise analysis problems and overvoltage issues | |
| 4) B. Predictive maintenance and misalignment | |
|
164. 164. What are the environmental factors mentioned in the article that can influence the importance of checking and cleaning ventilation paths? |
|
| 1) A. Noise analysis and misalignment | |
| 2) B. Dust concentration and debris | |
| 3) C. Voltage variations and humidity | |
| 4) D. Over-temperature and preventive maintenance | |
|
165. 165. What is a potential consequence of water particles condensing around a motor? |
|
| 1) C. Loosened terminals | |
| 2) D. Increased motor efficiency | |
| 3) A. Overheating | |
| 4) B. Vibration issues | |
|
166. 166. Which component should be regularly checked to prevent water from entering the motor? |
|
| 1) D. Power contactor terminals | |
| 2) C. Bearings | |
| 3) A. Cooling fan | |
| 4) B. Ventilation paths | |
|
167. 167. What is a common outcome of misalignment between the motor and the driven system? |
|
| 1) D. Better lubrication | |
| 2) A. Increased motor efficiency | |
| 3) B. Improved coupling elements | |
| 4) C. Vibration issues | |
|
168. 168. What can improper mounting of a motor lead to? |
|
| 1) D. Reduced vibration | |
| 2) C. Improved coupling | |
| 3) B. Misalignment | |
| 4) A. Increased motor efficiency | |
|
169. 169. Why is checking and maintaining bearings crucial for motor health? |
|
| 1) C. To prevent vibration issues | |
| 2) D. To avoid bearing and motor failures | |
| 3) B. To reduce noise levels | |
| 4) A. To increase motor efficiency | |
|
170. 170. How can single phasing impact a motor? |
|
| 1) D. Leads to motor burnout | |
| 2) C. Improves motor longevity | |
| 3) B. Causes protection system activation | |
| 4) A. Enhances motor performance | |
|
171. 171. What is the impact of over and under voltages on a motor's lifetime? |
|
| 1) A. Increases motor efficiency | |
| 2) B. Reduces motor temperature | |
| 3) D. Enhances motor performance | |
| 4) C. Decreases motor longevity | |
|
172. 172. Which of the following is a recommended preventive check for motor maintenance? |
|
| 1) D. Temperature analysis | |
| 2) A. Noise analysis | |
| 3) B. Vibration analysis | |
| 4) C. Cleaning motor from dust | |
|
173. 173. Why should the alignment of the motor be regularly checked? |
|
| 1) D. To improve bearing performance | |
| 2) C. To enhance coupling elements | |
| 3) B. To avoid misalignment issues | |
| 4) A. To reduce motor temperature | |
|
174. 174. What analysis can help identify potential motor issues through sound patterns? |
|
| 1) D. Performance analysis | |
| 2) C. Temperature analysis | |
| 3) B. Noise analysis | |
| 4) A. Vibration analysis | |
|
175. 175. What is the main purpose of the AR (Automatic Re-closing) in an electrical system? |
|
| 1) D. To delay power supply intentionally | |
| 2) B. To restore the operation of the system after a shutdown | |
| 3) C. To prevent any electrical malfunctions | |
| 4) A. To permanently shut down the system | |
|
176. 176. What is a prerequisite for the existence of the APV (Automatic Re-closing)? |
|
| 1) D. Specific activation conditions | |
| 2) C. Regular activation intervals | |
| 3) B. Absence of a ban on the second activation | |
| 4) A. Permanent ban on reactivation | |
|
177. 177. What are the main types of malfunctions that may cause a shutdown of the electrical system? |
|
| 1) D. Excessive power consumption | |
| 2) C. Voltage spikes | |
| 3) A. Software glitches | |
| 4) B. Short circuits, wire collisions, icing of wires | |
|
178. 178. What is the typical time delay for the operation of the AR? |
|
| 1) A. Several minutes | |
| 2) B. Instantaneous | |
| 3) C. 1-2 seconds | |
| 4) D. 0.2 – 0.5 to several seconds | |
|
179. 179. How does the response time of the AR vary with voltage? |
|
| 1) D. Response time is constant for all voltages | |
| 2) C. Voltage has no effect on response time | |
| 3) B. Higher voltage, shorter time delay | |
| 4) A. Higher voltage, longer time delay | |
|
180. 180. What factor influences the duration of the AR device's operation? |
|
| 1) D. Temperature | |
| 2) C. Frequency of malfunctions | |
| 3) B. Cross-section and material of wires | |
| 4) A. Voltage | |
|
181. 181. What distinguishes single-phase AR from three-phase AR? |
|
| 1) A. Voltage level | |
| 2) B. Time delay | |
| 3) C. Number of phases involved | |
| 4) D. Type of malfunction | |
|
182. 182. How are three-phase ARs further classified based on power supply? |
|
| 1) D. Synchronous and non-synchronous | |
| 2) C. Low-speed and high-speed | |
| 3) B. With one-way and two-way power supply | |
| 4) A. Single-phase and three-phase | |
|
183. 183. What is the characteristic of two-way AR with synchronism detection? |
|
| 1) D. Reactivates only one high-voltage switch | |
| 2) B. Supplies power first from one side, then from the other | |
| 3) C. Delays power supply intentionally | |
| 4) A. Simultaneous input of switches on both sides | |
|
184. 184. What is the purpose of high-speed AR? |
|
| 1) D. To prevent short circuits in the electrical network | |
| 2) C. To re-enable the system in the shortest possible period | |
| 3) B. To detect synchronism in the system | |
| 4) A. To cause intentional delays in reactivation | |
|
185. 185. What is the key consideration for the performance of Automatic Re-closing (AR)? |
|
| 1) D. Planned work schedule | |
| 2) C. Category of the consumer | |
| 3) A. Voltage levels | |
| 4) B. Transition speed and dissipation of electric arc | |
|
186. 186. What is emphasized regarding the resistance to emergency mode for Three-phase AR and backup protection devices? |
|
| 1) D. Delayed response time | |
| 2) C. Maintaining protection actions | |
| 3) B. Independence from electrical values | |
| 4) A. Rapid reduction in electrical values | |
|
187. 187. Why is selectivity of the AR important in an emergency automation system? |
|
| 1) D. To increase the speed of response | |
| 2) C. To coordinate with other emergency automation devices | |
| 3) A. To maximize operational shutdowns | |
| 4) B. To minimize planned work interruptions | |
|
188. 188. What precaution is advised when conducting planned work after operational shutdowns? |
|
| 1) D. Allow uncontrolled multiple AR for efficient operation | |
| 2) C. Remove AR from the circuit to prevent inadvertent voltage supply | |
| 3) B. Disconnect other protections to avoid interference | |
| 4) A. Maintain AR in the circuit for continuous protection | |
|
189. 189. What action is expected in case of an unsuccessful AR? |
|
| 1) D. Unblock multiple AR for better protection | |
| 2) A. Maintain the switching device in the on position | |
| 3) B. Automatic return to the on position | |
| 4) C. Keep the disconnected position for safety | |
|
190. 190. What is the primary function of a disconnector in an electrical system? |
|
| 1) D. Power disconnection for safety | |
| 2) B. Voltage stabilization | |
| 3) C. Power supply initiation | |
| 4) A. Current regulation | |
|
191. 191. How is a disconnector different from a circuit breaker? |
|
| 1) D. Circuit breakers are mainly for under-voltage conditions. | |
| 2) C. Disconnectors are for load current operations only. | |
| 3) B. Circuit breakers are used for visible gap creation. | |
| 4) A. Disconnectors have arc extinguishing devices. | |
|
192. 192. What is the purpose of disconnectors in outdoor installations during icy conditions? |
|
| 1) D. To regulate magnetizing currents | |
| 2) B. To destroy the ice crust | |
| 3) C. To extinguish load currents | |
| 4) A. To create a visible gap | |
|
193. 193. What distinguishes three-pole disconnectors from single-pole disconnectors? |
|
| 1) B. Lever drive control | |
| 2) C. Nature of movement | |
| 3) D. Equipped with horns | |
| 4) A. Operational isolation rod | |
|
194. 194. Why are insulation partitions installed between the poles of disconnectors? |
|
| 1) D. To facilitate outdoor installation | |
| 2) A. To decrease the on and off current | |
| 3) C. To increase the on and off current | |
| 4) B. To stabilize voltage changes | |
|
195. 195. What is the function of horns on the contacts of outdoor disconnectors? |
|
| 1) D. To destroy the ice crust formed during ice | |
| 2) C. To increase the on and off current | |
| 3) B. To facilitate turning off equalizing currents | |
| 4) A. To create a visible gap | |
|
196. 196. What kind of currents are allowed for disconnectors of 6-10 kV in closed switchgears? |
|
| 1) D. Over-voltage currents | |
| 2) B. Ground fault currents only | |
| 3) C. Charging currents and magnetizing currents | |
| 4) A. High load currents | |
|
197. 197. How does the installation of insulation partitions impact on and off currents for disconnectors of 6-10 kV? |
|
| 1) D. It decreases on current and increases off current. | |
| 2) B. It increases both on and off currents. | |
| 3) C. It has no impact on currents. | |
| 4) A. It decreases both on and off currents. | |
|
198. 198. What types of currents have disconnectors of 6-10 kV been confirmed to handle? |
|
| 1) D. Ground fault currents only | |
| 2) C. Charging currents and equalizing currents | |
| 3) B. Magnetization currents only | |
| 4) A. Only load currents | |
|
199. 199. What is the significance of turning on and off equalizing currents with disconnectors of 6-10 kV? |
|
| 1) D. To manage load redistribution during disconnecting or switching on electrical communication | |
| 2) C. To facilitate ground fault currents | |
| 3) A. To initiate power supply | |
| 4) B. To regulate magnetizing currents | |
|
200. 200. What is the primary function of a separator in a high-voltage circuit? |
|
| 1) B. To extinguish electric arcs | |
| 2) C. To disconnect damaged sections automatically | |
| 3) D. To regulate voltage transformers | |
| 4) A. To create artificial short circuits | |