Previous in Forum: Wound Rotor Motor   Next in Forum: How to Size Battery Bank for UPS
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
sagor
Participant

Join Date: May 2010
Posts: 2

Circuit Breaker Parameter

09/26/2010 1:54 AM

pls tell me , what is the defination of Io, Ir, Im, Icu, Ics of circuit breaker & what is the relation between between Icu & Ics.

thanks in advance
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
wareagle
Guru
United States - Member - New Member

Join Date: Jun 2008
Location: Alabama
Posts: 1604
Good Answers: 63
#1

Re: Circuit Breaker Parameter

09/26/2010 1:27 PM

Nest time google this yourself.

http://www.neweysonline.co.uk/neweys/pdf/Merlin_Gerin_Circuit_Breaker_Application_Guide_Technical.pdf
Register to Reply
SHAMITHGAMBHIR1
Power-User
India - Member - design engineer Engineering Fields - Electrical Engineering - New Member United Arab Emirates - Member - New Member

Join Date: Feb 2010
Location: dubai,mangalore,bangalore.....
Posts: 145
Good Answers: 8
#2

Re: Circuit Breaker Parameter

09/27/2010 4:40 AM

http://www.electrical-installation.org/wiki/Circuit-breaker

__________________
 shamith gambhir, electrical engineer
Register to Reply
electricalexpert65
Guru

Join Date: Oct 2009
Posts: 2061
Good Answers: 169
#3

Re: Circuit Breaker Parameter

09/28/2010 9:32 AM

Io - Pick-up Setting of the Earth Fault Relay or Release

Ir - Pick-up setting of the Overload Relay or Release

Im = Making Current (I think it should be 'Icm' - Short Circuit Making Current)

Icu = Rated Ultimate Short Circuit Breaking Current (means that the Breaker can break the designated Rated Ultimate Short Circuit Breaking Current for 2 times (i.e.) in an O-CO duty; after this the breaker cannot be continued in Service and must be replaced immediately)

Ics = Rated Service Short Circuit Breaking Current (means that the breaker can break the designated rated service short circuit breaking current for 3 times (i.e.) in an O-CO-CO duty; after this, the breaker can still be used as a switch-cum-isolator, till replacement is arranged; but, it cannot break anymore short circuit current; one must have some short of short circuit back up device like HRC Fuses, then.

Ics can either be 25% of Icu or 50% or 75% or 100% of Icu.
Register to Reply
Anonymous Poster
#4

Re: Circuit Breaker Parameter

09/29/2010 5:43 AM

i have got my answer. thanks everyone.
Register to Reply
Register to Reply
Have a Different Question?
4 comments
Copy to Clipboard

Users who posted comments:

Anonymous Poster (1); electricalexpert65 (1); SHAMITHGAMBHIR1 (1); wareagle (1)

Previous in Forum: Wound Rotor Motor   Next in Forum: How to Size Battery Bank for UPS

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 (96 right now)
Show Members
Advertisement