CosPhi on Transformer Name Plate ? 1

[rayas91]

Friends ,


There s no "CosPhi" on the Step up rating-name plate.Do we need cosphi for transformers ? Is it neccessary?I coulndt understand excatly this.


Thank you ,

 

[ScottyUK]

Transformers are rated in VA (or KVA, or MVA). There is no power factor, just the simple product of voltage applied to the winding and current flowing in it.

 

[rayas91]

Thank you for your interest...But i just wanted to know the reason what make it unneccesary.Can you explain if you know ?

 

[waross]

The power factor may vary from close to zero at no load when there is only magnetizing current flowing to very close to the load power factor when under load.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[prc]

During the initial days of electricity transmission, transformers were also rated for KW just as motors and generators. During the turn of last century, engineers decided to make the transformer rating to KVA as performance (except voltage regulation) is not affected by the power factor of the load.

 

[rayas91]

Thank you for all of you.