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

1 Answer

Answer :

Grounding electrode: A conductor driven in the earth and used for collecting ground current from or dissipating ground current into the earth. 

Grounding system: Comprises all interconnected grounding facilities in a specific area. 

Grounding resistance: The resistance offered by the ground when power frequency current is discharged to the ground through a particular grounding electrode or grounding system. 

Related questions

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

Last Answer : In resistance grounding system the neutral point of the load is connected to the ground to carry the residual current in case of unbalanced conditions. Resistance earthing system is done in an electric equipment in order to protect the equipment in occurrence of fault in the system.

Description : Factors on which soil resistance depends: a) depth of the electrode b) moisture c) Nacl d) all the above

Last Answer : Ans: D

Description : What is the difference between earth resistance and earth electrode resistance?

Last Answer : Only one of the terminals is evident in the earth resistance. In order to find the second terminal we should recourse to its definition:  Earth Resistance is the resistance existing between the ... the connection to it. (B) The contact resistance of the surrounding earth to the electrode.

Description : Ground resistance should be designed such that: a) grounding resistance should be as low as possible b) grounding resistance should be as high as possible c) grounding resistance should be always zero d) none of the above

Last Answer : Ans: A

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

Last 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)

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

Last Answer : It is mechanically unwide. Difficult to manufacture.  

Description : How value of grounding resistance could be kept constant?

Last Answer : While measuring of grounding resistance is more than computed design value 0.11Ω, then following are recommended to reduce it. Add in water the following highly conductive substances and pour into treated pit. ... sulphate (Cu SO4) e. Soft choke and f. Salt and charcoal in suitable proportions.  

Description : How grounding resistance could be measured?

Last Answer : There are few methods, which can give approximately true value. These are described below. a. Fall of potential method: This method is applicable for small grid or sub station where induction effect of ... method is influenced by induction  effect. d. Alternate - 2 of fall of potential method: 

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.

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 ... . Sheath of cables. d. Body of portable equipment such as iron, oven, etc.  

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.

Last Answer : Answer: A

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.

Description : How system grounding and equipment grounding achieved?  

Last Answer : System grounding is obtained by grounding the neutral through resistance, through transformer and through effective or solidly grounding. Equipment grounding is obtained by Grounding of non-current carrying metallic parts ... cables. d. Body of portable equipment such as iron, oven, etc.   

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. 

Description : The emf of a primary cell depends upon the: a) Physical dimension of the cell b) Nature of the electrolyte c) Nature of the electrode d) Both (b) and (c)

Last Answer : Ans: D

Description : The voltage at the reference electrode of the circuit shown in the illustration is applied to the input of a/an ______________. EL-0090 A. class A detector whose output drives an ... drives an 2-stage isolation transformer D. magnetic amplifier whose output controls a saturable reactor

Last Answer : Answer: D

Description : When the circuit shown in the illustration is operating correctly, the voltage at the reference electrode will be kept in the optimum range of ____________. EL-0090 A. 0.01 - 0.05 volt B. 0.80 - 0.85 volt C. 35 - 60 volts D. 100 - 115 volts

Last Answer : Answer: B

Description : What is electrode? 

Last Answer : A conducting element used for converging (centering) current to and from a medium is called electrode. There are two types of electrode. A positive and other is negative.

Description : When earth fault occurs: a) voltage potential at the earth mat increases due to grounding b) voltage potential at the earth mat decreases due to grounding c) voltage potential at the earth mat remains zero irrespective of fault d) none of the above

Last Answer : Ans: A

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

Last Answer : Ans: D

Description : The insulation of electric generators during short idle periods should be _____________. A. allowed to cool slowly to ambient temperatures B. flashed with direct current to remove any residual ... using strip or space heaters D. relieved of all capacitive charge by grounding the conductors

Last Answer : Answer: C

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

Last Answer : Answer: B

Description : If Relay #5 changed contact position grounding the 'auto' input to the 'pitch controller module', pitch control would be effected by the _________________. EL-0095 A. pitch feedback potentiometer B. Engine room thrust split potentiometer C. Engine room thrust lever only D. Bridge thrust lever only

Last Answer : Answer: B

Description : WHAT is ZIG ZAG Grounding Transformer

Last Answer : ANSWER: Three Single Phase Transformers can be connected to have a three phase Zig Zag Transformer. This system can be used for either grounding or developing a fourth WIRE from a three phase neutral. An example ... - three phase - three wire system to a 480Y/277 V - three phase - four wire system

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.

Description : What is the important of equipment grounding?

Last Answer : Equipment earthing ensures safety. 

Description : What are types of grounding?

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

Description : What is grounding?

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

Description : Why neutral breaker used in DG neutral grounding?

Last Answer : In case of high earth fault currents it is therefore normal practice to install a circuit breaker in the neutral of the generator in order to reduce the total fault clearance time. 

Description : How neutral grounding adopted? 

Last Answer : For above 3.3 kV and below 22 kV resistance grounding is preferred. In this voltage level capacitive ground current is not large, so reactance grounding is not used. For below 3.3 kV ... in transmission lines, generators etc. to neutralize capacitive current by adding reactive current.  

Description : What are the types of Grounding? 

Last Answer : Equipment grounding is the grounding on non-current carrying metal parts. This is done for personnel safety of the operator and for the equipment safety by blowing the fuse when earth fault current flows ... Mainly there are three types of neutral earthing a) Directly b) Resistance c) Reactance 

Description : In case new installation is to be done, what basic guidelines should be followed for grounding?

Last Answer : a. Earthing conductors in outdoor areas shall be burried 500 mm below finished grade level unless stated otherwise.  b. Minimum 6000 mm spacing between rod pipe electrode shall be provided unless ... pipe or plate electrode treated earth pit, which in turn shall be connected to station earthing.  

Description : Why copper is only preferred as material for grounding?

Last Answer : An advantage of use of copper is in addition to their high conductivity, has the advantage of being resistant to underground corrosion. Copper is cathodic with respect to other metals that are ... and zinc reduces by about 50% and practically eliminates this potential with respect to lead.   

Description : What are the specifications for procurement of grounding conductor and grounding rods?

Last Answer : Grounding conductor, pad, rods etc. should have following specifications: a. Copper : 91.8 to 94.9% b. Zinc : 2.0 to 3.0% c. Tin : 0.8 to 1.5% d. Lead : 2.0 to 2.5% e. Iron : 0.5 to ... : 0.3% maximum. b. Antimony : 0.3% maximum. c. Manganese : 0.04% maximum. d. Phosphorous : 0.04% maximum. 

Description : Why fences grounding are important?

Last Answer : Because the most dangerous touch contacts involves and outside the fence are usually accessible to the general public. In order to minimise the effect of step potential and touch potential ... either case, the perimeter ground conductor and fence are bonded electrically at frequent intervals.  

Description : Why grounding mat is important near ground switch operating handle and disconnecting switch operating handle?

Last Answer : Equipment operating handles deserve special attention because of the higher probability for co-incidence of adverse factors. For example, a. Hand operation equipment such as grounding switches and disconnecting ... both in order to bring down the values of touch potential and step potential.  

Description : Why grounding of power cable is needed? How it should be done?

Last Answer : a. The magnetic fluxes produced by the three phases in a multi core power cable almost cancel put each other, since the vector sum of these currents at any instant is zero and practically ... . The sheaths of shielded control cables should be grounded at both ends to eliminate induced potentials.  

Description : Why grounding is necessary?

Last Answer : The purpose of grounding is to maintain the surface under and around a station ate as nearly zero potential as possible with reference to absolute earth so that operating staff who walk in the ... equipments are ate earth potential and when faults occur there is safety to staff and equipments. 

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. 

Description : What is the important of equipment grounding?

Last Answer : Equipment earthing ensures safety.  

Description : What are types of grounding?

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

Description : What is grounding? 

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

Description : Explain briefly about grounding of cable trays. 

Last Answer : Cable trays are grounded because to avoid any shocks to personnel incase of leakage. A grounding wire runs at the side of tray through a parallel groove clamp through out the length of the cable tray. If ... another we can loop up the grounding wire to the tray below. This saves extra ground wire. 

Description : What is the purpose of grounding secondary of the control transformer? 

Last Answer : To protect the operating personnel from high induced voltage.  

Description : Pick out the wrong statement. (A) Seam welding, projection welding & spot welding are the classification of electrical resistance welding (B) Electrode tip in spot welding is of copper and the ... joined are overlapped and placed between two electrodes (D) Mild steel sheet cannot be spot welded

Last Answer : (D) Mild steel sheet cannot be spot welded

Description : Material of construction of the electrode used in the electric resistance welding is (A) Stainless steel (B) Graphite (C) Copper (D) Steel

Last Answer : Option C

Description : Earth resistance comprises of   A. Resistance of soil away from electrode.   B. Contact resistance between electrode and soil.   C. Resistance of metal electrode   (a) A only  (b) A and B only   (c) A and C only  (d) A, B and C together 

Last Answer : D

Description : From the point of view of safety, the resistance of earthing electrode should be   (a) Low (b) High (c) Medium (d) The value of resistance of earth does not affect the safety 

Last Answer : A