IPB


Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
3 Phase Circuit, Unbalnced load
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
rseee
post Jun 5 2008, 04:04 AM
Post #1


Intermediate Member
***

Group: Full Member
Posts: 13
Joined: 9-May 08
Member No.: 4,547



what are the causes of Unbalanced load in 3 phase circuits?
How large unbalanced load causes burning of motor?
Go to the top of the page
 
+Quote Post
subrao
post Jul 17 2008, 01:04 PM
Post #2


Intermediate Member
***

Group: Full Member
Posts: 12
Joined: 16-September 07
Member No.: 3,794



There are basically two sources of unbalanced currents in a 3-phase system driving motor loads
1 From source voltage
source voltage is not perfectly balanced.Either magnitudes of the phase voltages are not exactly equal or the phase angle between them is not exactly 120 degrees
2.From load side There is unbalance in connected load
3. Defective motor
No .of turns on all phase windings are not exactly same.
windings are not distributed equally in space may be due to problem in number of slots that is number of slots not divisible by phase-pole belts.
Generally speaking a standard motor can take an unbalance voltage of 1%. Beyond this it has to be de-rated and used up to 5% unbalance. Above 5% unbalance it should not be operated
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   4 Itos 1,697 24th June 2002 - 04:02 AM
Last post by: Itos
No New Posts   1 Itos 1,447 26th June 2002 - 08:56 PM
Last post by: marke
No New Posts   3 andy 1,386 5th September 2003 - 11:55 PM
Last post by: Underling
No New Posts   0 andy 1,290 20th September 2002 - 04:44 AM
Last post by: andy
No New Posts   0 andy 475 --
Last post by: andy



RSS Lo-Fi Version Time is now: 16th October 2008 - 12:14 AM
hosted by : L M Photonics Ltd