20.1.1 | List the basic principles or factors thatneed to be considered during design of a power distribution system.
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20.1.2 | Describe how a shunt capacitor can be used to improve voltage regulation on a distribution network
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20.1.3 | List thecategories of equipment that areused in power networks.
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20.1.4 | List the different electrical faults that can occur in a power system and use a diagram to illustrate these.
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20.1.5 | Calculate the magnitude of the short-circuit current in a single-phase circuit with a nominal open circuit voltage of 1000V if the equivalent source impedance is 5 milli (5 x 10-3) Ohms (NB show all calculations)
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20.1.6 | What assumptions are usually madewhen performing simplified fault current calculations?
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20.1.7 | Describe three main functions of switchgear.
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20.1.8 | Briefly describe the characteristics of the following MV switchgear: - Switches
- Isolators/disconnectors
- Circuit breakers
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20.1.9 | Compare the advantages and disadvantages of the following types of switchgear insulation: (a) Oil (b) Air break (c) Sulphur-Hexaflouride (SF6) (d) Vacuum
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20.1.10 | What factors should be considered when selecting switchgear for a specific application.
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20.1.11 | List the functions of a typical modern protection relays.
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20.1.12 | In what applications would the following types of cable be used. - XLPE
- PILC
- PVC
- Elastomeric
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20.1.13 | What factors need to be considered when selecting a cable for a specific application?
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20.1.14 | Describe what methods can be used to calculate the voltage drop in a length of cable.
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20.1.15 | Describe how a cable is selected to ensure it can safely carry a fault current.
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20.1.16 | How do environmental conditions influence the current rating of cables?
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20.1.17 | Describe the precautions should be taken when installing cables to ensure the maximum service life?
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20.1.18 | With the use of a diagram illustrate how a delta/star transformer can be connected to give standard polarity and standard phase sequence. | (3) |
20.1.19 | List three methods how transformer neutrals can be earthed and comment on their prospective fault current.
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20.1.20 | Compare the advantages and disadvantages of forced and natural transformer cooling.
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20.1.21 | Whattypes of faults transformer faults can occur in power transformers?
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20.1.22 | What is differential protection? Describe how it is used to protect a power transformer.
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20.1.23 | Use an illustration to explain the concept of power factor.
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20.1.24 | List the effects of sustained low power factor on equipment.
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20.1.25 | What methods can be used to improve power factor?
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20.1.26 | Are there any economic benefits of power factor correction? Explain.
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20.1.27 | Discuss the fundamental reasons why equipment and structures are grounded/earthed.
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20.1.28 | Describe how equipment grounding can reduce the shock hazards to personnel.
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20.1.29 | Describe the zoned protection approach to mitigation of lightning and switching surges.
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20.1.30 | Illustrate the principles of core balance protection using a diagram.
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20.1.31 | Compare the advantages and disadvantages of solid earthingwithresistance earthing systems Please see section 2 below. | (3) |