IPB

Welcome Guest ( Log In | Register )

Quick Register
Welcome Guest, Register to Remove this Message!
Hello and welcome to LMPForum, like most online communities you must register to view or post in our community, but don't worry this is a simple free process that requires minimal information. Take advantage of it immediately Register Now

There are many great features that are not available to guests at LMPForum
Login User Name

Login Password



Forgot Password

Tags
This content has not been tagged yet
 
Reply to this topicStart new topic
Short Curcuit Current
Digg this topic · Save to del.icio.us · Slashdot It · Post to Technorati · Post to Furl · Submit to Reddit · Share on Facebook · Fark It · Googlize This Post · Add to ma.gnolia · Tag to Wink · Add to MyWeb · Add to Netscape
HienN
post Mar 3 2010, 03:26 PM
Post #1


Junior Member
**

Group: Full Member
Posts: 8
Joined: 25-July 09
Member No.: 5,969



Hi guys,

Could you enlighten me on this case?

1. If I calculate the SC current in power system and it showed 17kA.
2. What will happen when I choose the MCCB with SC current rated at 10kA if there is SC in the system?
3. What wil happen when I choose the MCCb with SC current rate at 40kA if there is SC in the system?
4. What exactly is the SC current for the MCCB here?
5. Overcurrent protection will do nothing in this SC case?
6. What exactly the SC current on the MCCb's nameplate means?

Regards,


Go to the top of the page
 
+Quote Post
asif
post Mar 6 2010, 10:16 AM
Post #2


Intermediate Member
***

Group: Full Member
Posts: 20
Joined: 20-August 06
From: INDIA
Member No.: 1,814



QUOTE (HienN @ Mar 3 2010, 08:56 PM) *
Hi guys,

Could you enlighten me on this case?

1. If I calculate the SC current in power system and it showed 17kA.
2. What will happen when I choose the MCCB with SC current rated at 10kA if there is SC in the system?
3. What wil happen when I choose the MCCb with SC current rate at 40kA if there is SC in the system?
4. What exactly is the SC current for the MCCB here?
5. Overcurrent protection will do nothing in this SC case?
6. What exactly the SC current on the MCCb's nameplate means?

Regards,


Hi HienN,
10kA rating of a MCCB is the maximum short circuit current it can interrupt. If the fault level is more than 10kA, then MCCB won't be able to extinguish the arc fully & there is chance of burnt off contacts & in some cases, explosion due to heat developped inside case. Better you can go for 25kA rating MCCB.

If it is 40kA rated MCCB, then there is no problem unless you are not concerned about cost of MCCB. You may still get MCCB of 25kA rating which will be less costly than 40kA.

The basic difference between OC & SC operation is time factor. Short time delay & Long time delay are different for both operations.

Short circuit current on the MCCB's name plate is the capacity of MCCB to interrupt a fault of that level safely.

Thanks & Regards,
Asif Mansoori
Mumbai


Go to the top of the page
 
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



Collapse

> Similar Topics

    Topic Title Replies Topic Starter Views Last Action
No New Posts   1 -shahbaz ali- 4,881 28th August 2002 - 09:32 AM
Last post by: marke
No New Posts   0 -shahbaz ali- 2,162 --
Last post by: shahbaz ali
No New Posts   10 theDOG 2,740 25th September 2002 - 10:39 AM
Last post by: marke
No New Posts   1 tom 5,631 15th August 2003 - 04:00 PM
Last post by: merajdab
No New Posts   5 d-mark 2,366 29th January 2003 - 06:23 PM
Last post by: marke


RSS Lo-Fi Version Time is now: 3rd September 2010 - 04:51 PM
hosted by : L M Photonics Ltd
LMPhotonics Home  Power factor  Motor Control  Single Phase Motors  Slipring Motors  Motor Starters  Soft Starters  Variable Speed  Energy Savers