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In one of the industrial site, the no earthed system has been chosen in electrical designing stage. Therefore nobody anticipated a strong earth fault current in the system.
Author : Hamid - From: Iran
According to IEEE 665 – section page 27, it is important for the ground conductor to run as close as possible to the phase circuit conductors; since it will cause the fault current return path reactance to be reduced.
Author : Hamid
The electronic control systems in one power plant are digital base and separated "one point" grounding system is considered for it.
Author : Hamid
We have 25 earthing pits in telecom building these earthing pits conneted with each other with a lop could any one tel me in detail.
Author : maamir from pakistan
A design query on earthing trafo.
An earthing trafo installed on a 11 kv switchboard is rated for 381 kva , 11 kv/ 110v in a star - broken delta arrangement. A resistor rated 1.14 ohms is connected across the broken limb. ...
Author : Guest
Is there any potential hazard in bringing the neutral of several 11kV/400V Dyn11 transformers to a common earth bar and then connecting to the earth pits?
Author : Mohan
How to design a neutral grounding resistor for 5 MW generator and what are the points to be considered before design a NGR for generator? Kindly give some design methods or articles regarding this.
Author : T.Kailash Kumar
I was going through 11kV schemes.For every phase R,Y,B there is an individual Potential transformer for the outgoing feeder.
Author : GUEST
According to electrical basic design of one industrial plant, contractor shall supply suitable grounding transformer with an additional NGR in its neutral connection for limitation of ground fault current system to 400 A.
Author : Hamid - From: Iran
What is the origin of neutral bar voltage and how we can reduce it?
Author : Reza - From: IRAN
What is the advantage and disadvantage of combination of power transformers MV/LV grounding systems? Whether can we use the cable armor as grounding conductor in power system?
Author : SABA - From: IRAN
How can we choose the neutral wire size in various grounding system? Is there any guideline for non liner loads conditions?
Author : Ebrahim - From: IRAN
Recently we have carried out the periodic inspection in a manufacturing plant. This plant has a 6.6kv network supplying 3 remote buildings each with transformers. We found that the Zs readings throughout the installation in one of the buildings were high compared to previous inspection reports.
Author : Dale - From: England
We have a 11kV/400V 4MVA trafo with 97kA short ckt rating. Can u suggest for the neutral grounding methodology keeping high shrt ckt rating of the system
Author : san - From: INDIA
What consideration shall be taken in lightning protection grounding systems? Are there any estimation for lightning current surge?
Author : Hamed - From: Iran
i want to know how do u calculate the ohmic resistance value of ngr for transformer protection,say if i do provide u primary seconday voltage ,current of transformer.
Author : bipul pandey - From: india
In parallel operation of generators, Sometimes the neutral point of one of them is grounded and other not. Are there any technical reason for this operation way?

Author : Mohammed amin - From: Egypt
What is advantage and disadvantage of various grounding systems such as solidly, low impedance or high impedance grounding systems?
Author : Guest - From: Syria

What amount of grounding impedance shall be considered in grounding system planning stage?
Author : S.O - From: Turkey
Why do we ground positive terminal of electro-static-precipitator (ESP)?
Author : Yogi - From: India
Is there any technical guide for choosing  the best grounding system between IT,TT or TN systems?
Author : Reza - From: Iran
I urgently need the main earthing conductor sizing calculation of 132kV substation
Author : Asif - From: Abu dhabi
Is it possible to connect such a transformer solidly grounded ( 10/0.4 kv Dyn11 auxilary transformer ) in same grounding as individually high resistance grounded 10kV generator units?
Author : Guest
In my house we do not have access to earth, can we use neutral wire instead of earth electrode for grounding of metal enclose of electrical equipments?
Author : Javad
I was interested in finding the suitable cross sectional area of the MV lightning arrestor ground electrode. Any adeas?
Author : Vajira Wijekoon - From: Sri Lanka
wire size for one megawatt ac generator for grounding
Author : Yasir - From: Pakistan
Any one can sugguest for neutral cable size for 75mva, 66/22kv, delta/ star)?.my neutral cable is connecting thro NGR value is 6.5 ohm. fault level is31.5kA. lv cable size is 3x(3x1c 630).provide sample calculation also.
Author : skr - From: india
Inside of an Electrical Room (ER) there are MV and LV equipments. Is it correct joining the ground bars of MV and LV circuits?
Author : Luis Milla - From: Peru
What are the components used in providing an earth monitoring system in a hospital?Where else we need an earth monitoring system?How many types of earth monitoring systems are available?Give drawings and basics of each system.
Author : Sinnadurai Sripadmanaban - From: Srilanka
What are the additives recommended to improve resistivity of earth for various kinds of ground conditions like type of soil,moisture content,minerals,salt,dyes  etc ...
Author : Sinnadurai Sripadmanaban - From: Srilanka
Grounding Of Neutrals Of generators in parallel..... what could be the level of problem
Author : Kshitij Pandey - From: India
Is it necessary to connect star point of Primary of VT (Y-Y) to earth in a resistance grounded system?
Author : Mahesh - From: India
When two source have their own NGR ( Wye ground)- Zero sequence can not be detected correctly. ...
Author : Roxy - From: India
Why Neutral is used in Electrical System?
Author : Fayaz - From: India
What will be the value of ground fault current?
Say, I have a substation which is fed from a 630kVA, 11/0.433kV, 4% impedance, Dyn11, solidly grounded neutral transformer. ...
Author : Bishu - From: India
We are using grounding transformer of following specs
rated voltage 33 kV, connection Zn(zigzag) , fault current/ph -266.7/30s, Zo=52.7ohms/ph Po=1244 W , Io=0.07 A
Author : Sunil - From: India
How do i calculate the number ground rods for different grounding systems? is it possible to make only one grounding system for electrical, equipment, instrumentation and lightning protection grounding?
Author : Deusdedit malulu - From: Tanzania
I wonder if we can use one NGR for six 9 MW Alternators having 11 kV Gen voltage? can some one help out, how to design/calculate the Resistor value
Author : Aijaz - From: Pakistani
Explain the grounding methods of Instrument Transformers in  EHV  Substation
Author : soman - From: India
Explain the Grounding methods and affecting parameters in EHV  UG  cable joints.
Author : Soman - From: India
I have seen one video in which a man standing at the top of the train get shock after touching the conductor (man immediately dies) however ....
Author : Deepak
Grounding of 3nos  l.v 400v orif it is for m.v 13.8kv generators
is it better to have separated individual earth pit for each gen , better than collecting ....
Author : mohammed hasssen - From: Egypt
Six No 11kv star connected generators are paralleled with each other on common bus through dedicated bus. Common Low resistor NGR with ....
Author : Muhammad Waqas - From: Pakistan
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