Previous in Forum: Power Generator Sizing   Next in Forum: Grounding Under/Below 10 Ohms!
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
3 comments
Rate Comments: Nested
Anonymous Poster

DG Neutral Earthing

08/05/2010 12:58 PM

I have a system of 3 Dg Sets of 1000 KVA .

The DG neutrals are grounded through neutral contactor which operates on a logic that only one neutral is closed in case of multiple DG Sets synchronised running.

My question is that when neutral of only one DG Set is closed and neutral of other DG Sets are not earthed , then how does the earthfaultrelay of the DG Sets who,s neutral is not earthed act in case of earth fault in those DG Sets .

or is it that the earthfault relay of the DG who,s neutral is closed will always act irrespective of whichever DG has earh fault
Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Good Answers:

These comments received enough positive votes to make them "good answers".
2
msamad
Guru

Join Date: Feb 2009
Location: Houston, USA
Posts: 946
Good Answers: 244
#1

Re: DG Neutral Earthing

08/05/2010 8:18 PM

First of all, the neutral is grounded not for only the earth fault (or ground fault) within the generator; it is mostly used for earth fault of the system. When the generators run in parallel, they all are connected to the same bus and same neutral. So, if any earth fault occurs in the system including within any of the generators (even their own neutral is not grounded), the current flows through the neutral and the system trips.

These previous threads also may help:
http://cr4.globalspec.com/thread/36055

http://cr4.globalspec.com/thread/50263

- MS

__________________
 "All my technical advices in this forum must be consulted with and approved by a local registered professional engineer before implementation" - Mohammed Samad (Linkedin Profile: http://www.linkedin.com/in/msamad)
Reply Good Answer (Score 2)
No more Good Answers.
giri
Power-User

Join Date: May 2009
Location: Some where on Earth !!!.
Posts: 243
Good Answers: 2
#3
In reply to #1

Re: DG Neutral Earthing

08/09/2010 1:43 PM

Dear Msamad, A nice explanation by you in the older post...Thank you....I have a doubt here but.How the other DGS were protected against the winding fault if it's given a restricted earth fault protection.?

__________________
 "Know something about everything and everything about something"
Reply
Energy Conservation
Active Contributor

Join Date: Jul 2010
Posts: 11
#2

Re: DG Neutral Earthing

08/07/2010 2:50 AM

check this thread also http://cr4.globalspec.com/thread/36055
Reply
Reply to Forum Thread
Have a Different Question?
3 comments

Good Answers:

These comments received enough positive votes to make them "good answers".
Copy to Clipboard

Users who posted comments:

Energy Conservation (1); giri (1); msamad (1)

Previous in Forum: Power Generator Sizing   Next in Forum: Grounding Under/Below 10 Ohms!

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
Electrical Engineering:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (92 right now)
Show Members
Advertisement