star delta 1

[jib]

if motor labeling is lost what is the best way to indetify
the six connection on a star delta motor and to recconect

 

[motorsdirect]

Hi
First, I would inspect the leads to see if there are any clues at all..sometimes the leads are bought out of the motor in groups of 3... or bound in groups of 3 giving you a hint to either side of your connection block...lets say a1,b1,c1....as one side..and c2,a2,b2..as the other.
Then, using a resistance meter, work out the three windings..there should be three seperate pairs of leads that read to each other!!
if there are no more clues at all..then, i would take an educated guess at the groups of three,,connecting your pairs to a1 & a2, b1 & b2, c1 & c2.
Then I would star the a2,b2,c2 leads..and supply a1,b1 &c1. and run the motor...being careful to listen to the motor when switching on...the only thing left could be reversed phase....if you have this...the motor wont start properly...will growl loudly..so switch it straight back off...then swap over 1 pair of leads at a time( ie...a1 & a2)...then testing again....putting them back as they were if no improvement is made!!!!
There should only be 1 pair that needs to be reversed to make the motor run correctly!!!

Hope this makes sense...
Jeff

http://www.motors-direct.co.uk

 

[jib]

many thanks this has been helpful can you reccomend any good books on star delta circuits
regards joe

 

[motorsdirect]

Hi Joe.
You could start by looking at Mark Empsons web site:

http://www.lmphotonics.com

If this is not enough for you...I have a very old but good book called 'ELECTRIC MOTOR REPAIR' its by Robert Rosenberg + August Hand...and is published by 'HRW'...whcich stands for HOLT, RINEHART AND WINSTON.

hope this helps
Jeff

http://www.motors-direct.co.uk

 

[jib]

many thanks again jeff
regards joe