Thread: 51 & 49 function relay
LinkBack URL
About LinkBacks- 12-01-2009 #1Junior Member
- Join Date
- Jan 2009
- Posts
- 2
- Thanks
- 0
- Thanked 0 Times in 0 Posts
51 & 49 function relay
Hi all
New to the forum, can everyone help me to explain the difference between 51 and 49 function relay incase motor protection.
Thank you------------------You can do, Do it now
- 12-01-2009 #2Senior Member
- Join Date
- Dec 2008
- Posts
- 369
- Thanks
- 0
- Thanked 0 Times in 0 Posts
Re: 51 & 49 function relay
tooo vague
Originally Posted by Tran_Lap 
- 12-01-2009 #3Senior Member
- Join Date
- Dec 2007
- Posts
- 196
- Thanks
- 0
- Thanked 0 Times in 0 Posts
Re: 51 & 49 function relay
What do you mean exactly 51 & 49??, is this on the contactor overload??
- 12-01-2009 #4Super Moderator
- Join Date
- Dec 2008
- Location
- South Wales
- Posts
- 5,525
- Thanks
- 3
- Thanked 9 Times in 4 Posts
Re: 51 & 49 function relay
Hey.
With regard to motor protection there are a number of different relays that have different jobs.
Function 49 is overload protection
Function 51 is locked rotor protection.
There are lots of others - 50 = phase fault protection
50N = earth fault protection
50 + 51N = Time overcurrent with thermal in built.
You can also get harmonic protection etc etc
Hope this helps
CheersLast edited by Lenny; 12-01-2009 at 06:56 PM.
- 13-01-2009 #5Junior Member
- Join Date
- Jan 2009
- Posts
- 2
- Thanks
- 0
- Thanked 0 Times in 0 Posts
Re: 51 & 49 function relay
my understanding 51 using for overcurrent protection, but the reason of overcurrent is overload, 49 is thermal relay and the reason is overload too. So, can I use one of them for overload protection? when do I use both ?
thank youLast edited by Tran_Lap; 13-01-2009 at 04:18 AM.
------------------You can do, Do it now
Reply With QuoteSimilar Threads
-
Trying to find a relay
By Dorian.Fabre in forum Electrical Forum | General Electrical ForumReplies: 4Last Post: 18-10-2009, 08:21 AM -
a Synchronism check relay
By bejoyengineer in forum Commercial and Industrial ElectricalReplies: 1Last Post: 29-03-2009, 04:35 PM -
low voltage relay?
By jimbo198966 in forum Commercial and Industrial ElectricalReplies: 4Last Post: 10-03-2009, 12:53 PM -
please explain relay settings
By ericsson in forum Electrical Forum | General Electrical ForumReplies: 3Last Post: 15-01-2009, 06:01 PM
Visitors found this page by searching for:
Nobody landed on this page from a search engine, yet!
Tags for this Thread
Posting Permissions
- You may not post new threads
- You may not post replies
- You may not post attachments
- You may not edit your posts
Bookmarks