SEL 487 XFMR Differential 1

[Engineer1916]

Eng Tips Family,
DO any of you guys have any good material on calculating setpoints for differential relays? I am working on a SEL 487. Any help would be appreciated.

 

[stevenal]

IEEE C37.91 and the relay instruction manual.

 

[DBL-E]

Read the manual, SEL has good documentation so there is a specific section on setting the differential and how it works.

Additionally CT saturation is going to be the main issue to look out for so read this white paper too:

https://cms-cdn.selinc.com/assets/L...eePoint_AH_20200501_Web.pdf?v=20200504-195517