Three Ct Of Alternator Brust

[rajeev]

Dear All

 

 

CT for Alternator-. One Big problem occurred due to CT.One days Power Plant was running smoothly then suddenly trip due to differential protection then checked alternator side & found that One CT was burst & neutral side also melt. Other two CT Also cracked. Then checked Alternator (8MW) thoroughly but no problem found alternator side. Then change Three CT with spare one. Now Plant is running smoothly.

 

So that I think This CT was burst internal heating .but I don’t know why three ct was burn.

 

I want to ask about this because every thing is ok but suddenly it was happen.

 

So please send me the reasons of the failure & Solution. If

 

 

[marke]

Hello rajeev

 

Welcome to the forum.

 

It sounds like the burden on the CTs does not match the rating of the CTs.

CTs have a rated burden, typically 3VA or 5VA. If you use a 3VA CT with a 10VA load, the power dissipated in the CT will be higher and the CT temperature will rise. You will also have non linearity at high loads.

 

Check the voltage across the CT secondary terminals at rated current with the load circuits connected. Multiply the voltage by the the current to get the VA and compare this with the CT rating.

 

Best regards,

Mark.