Previous in Forum: How to Determine the Number of Cores and Core Ratio of CT's to be Used?   Next in Forum: Capacitor Bank
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
4 comments
Rate Comments: Nested
fikri.aziz
Participant

Join Date: Dec 2012
Posts: 1

Neutral Earth Resistor(NER) Indication at Switcgear

12/25/2012 11:12 PM

I have a 6.35kV NER for 33kV/11kV 10MVA Transformer. My client asking to put the NER indication and interlocking at switchgear panel . I am considering semaphore indication for monitoring but at the interlocking part I am still in not sure.

Please advise what aspect I need to look on and advise also on the connection since I am still new in designing.

Thanks in advance.
Register to Reply
Pathfinder Tags: NER
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
arifkunnath
Commentator

Join Date: Oct 2011
Posts: 95
#1

Re: Neutral Earth Resistor(NER) Indication at Switcgear

12/26/2012 2:59 AM

Please see this site

dimako.com/more-products/neutral-earthing-protection-system/
Register to Reply
debata07
Power-User

Join Date: Nov 2011
Posts: 131
Good Answers: 5
#2

Re: Neutral Earth Resistor(NER) Indication at Switcgear

12/26/2012 11:03 PM

You may provide a neutral CT for monitoring current in the NER circuit as well as earth fault protection. The CT will have two cores. One core can be connected to an ammeter or a current transducer for monitoring earth fault current on continuous basis. The second core can be connected to a earth fault relay for tripping the circuit breaker in the switchgear panel in the event of earth fault current exceeding the set point of the relay.
Register to Reply
moody
Participant

Join Date: Sep 2009
Location: EGYPT
Posts: 4
#3

Re: Neutral Earth Resistor(NER) Indication at Switcgear

12/27/2012 5:31 AM

hii fikri, if u are from egypt mail me at.

CR4 Admin - email address removed

From the CR4 Rules: Do not post phone numbers or email addresses. The CR4 Admin will delete all phone numbers and email addresses posted in threads or comments. You can share this information via the CR4 internal messaging system.

__________________
 Proudly I am MUSLIM
Register to Reply Off Topic (Score 5)
eugene344
Active Contributor

Join Date: Jun 2011
Posts: 24
Good Answers: 4
#4

Re: Neutral Earth Resistor(NER) Indication at Switcgear

12/27/2012 9:01 PM

NER interlocking usually includes tripping of the transformer/s if the neutral is not earthed (neither the NER nor direct earth connection in service.)

If this interlocking is part of the specified system, include an audible alarm for the neutral not earhed, and consider a time delay long enough for an operator to correct (i.e. reconnect the neutral earth) before the transfomer trips.
Register to Reply
Register to Reply
Have a Different Question?
4 comments
Copy to Clipboard

Users who posted comments:

arifkunnath (1); debata07 (1); eugene344 (1); moody (1)

Previous in Forum: How to Determine the Number of Cores and Core Ratio of CT's to be Used?   Next in Forum: Capacitor Bank

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 (59 right now)
Show Members
Advertisement