Why resistance grounding preferred for less than 33 kV and more than 415 V?

Why resistance grounding preferred for less than 33 kV and more than 415 V?
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1 Answer

Answer :

a) To limit the earth fault current for equipment safety else, high short ckt forces dislocate in windings/bus bars etc,

b) Over voltage due to arcing ground reduced

c) Permits earth fault protection (not possible in ungrounded system)
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Related questions

What are the types of cables used in 6.6 kV and 415 V system voltages?

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What are the interlocks between 415 V and 6.6 kV switch gear?

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What is the difference between lockout of 6.6 kV and 415 V CB’s?

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Why copper is only preferred as material for grounding?

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What are the built in protections provided in 415 V breaker?

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Why neutrals are solid grounded above 33 kV?

Description : Why neutrals are solid grounded above 33 kV? 

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Why core balance CT is preferred over residual connected CT’s to sense earth fault in 6.6 kV feeders?

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Description : Why not high resistance for earth fault than using grounding transformer & resistor 0.45 ohms?

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What is different between resistance grounding system and resistance earthing system?

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How value of grounding resistance could be kept constant?

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How grounding resistance could be measured?

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What does mean by grounding electrode, grounding system, and grounding resistance?

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How many insulator disc used for 33 kV transmission voltage line?

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Why the earthing transformer primary voltage is 16.5 kV rated in main generator even though actual voltage during the E/F is root 3 times less?

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V=100Sin (1000t+46 deg), I=2Sin (1000t+80 deg) what are the elements in the circuit a) R=30 ohm, L=30 mH b) R=30 ohm, C=33.3 micro farads c) R=40 ohm, L=30 mH d) R=40 ohm, L=33.3 micro farads

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Which of the following statements is/are true regarding requirements for receptacle outlets aboard vessels? A. Each receptacle outlet operating at 100 volts or more must have a grounding pole. B. Outlets connecting a lifeboat and the vessel's electrical system must have threaded plugs. C. Machinery spaces must contain sufficient outlets for lighting all machinery with a portable light having a 50 foot flexible cord. D. All of the above.

Description : Which of the following statements is/are true regarding requirements for receptacle outlets aboard vessels? A. Each receptacle outlet operating at 100 volts or more must have a grounding pole. B. Outlets ... machinery with a portable light having a 50 foot flexible cord. D. All of the above.

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Emulsifier protection is associated with: a) Grounding protection b) Dielectric strength protection of cables and conductors c) Lightning protection d) Fire protection

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Temporary repairs to an open DC propulsion armature coil can be made by _____________. A. connecting the coil ends directly to a pair of negative brushes B. disconnecting coil ends, insulating each, and short circuiting the two commutator bars C. grounding the coil ends and short circuiting the commutator bar D. removing the sparking brushes

Description : Temporary repairs to an open DC propulsion armature coil can be made by _____________. A. connecting the coil ends directly to a pair of negative brushes B. disconnecting coil ends, insulating ... C. grounding the coil ends and short circuiting the commutator bar D. removing the sparking brushes

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How safety could be ensured by equipment grounding?

Description : How safety could be ensured by equipment grounding?

Last Answer : In order to enumerate this, let us first find out the effects of current and voltage developed during fault condition.

What is the important of equipment grounding?

Description : What is the important of equipment grounding?

Last Answer : Equipment earthing ensures safety. 

What is the important of system grounding?

Description : What is the important of system grounding?

Last Answer : It is important because: a. Earth fault protection is based on the method of neutral earthing. b. System voltage during earth fault depends on neutral earthing. c. It is a protection against arcing grounds, unbalanced voltages with respect to earth and lighting.

What does mean by equipment grounding?

Description : What does mean by equipment grounding?

Last Answer : Grounding of non-current carrying metallic parts is called equipment grounding. For instance no-current carrying parts include the following: a. Motor body, switchgear metal enclosure, transformer tank, conduits of ... c. Sheath of cables. d. Body of portable equipment such as iron, oven, etc.

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Last Answer : There are two types a. System grounding. b. Equipment grounding.

What is difference between earthing and grounding?

Description : What is difference between earthing and grounding?

Last Answer : Both have same meaning. The term earthing is used in U.K. and grounding in U.S.A.ground means earth.

What is grounding?

Description : What is grounding?

Last Answer : It is an electrical connection with the general mass of earth through an earth electrode.