Motor relay pu current?

[Riyad]

Hi all,
What is meant by the motor relay was tested at 1.0 p.u. of FLA?
and what is greater 5.5 p.u. or 1.0 p.u?

Thanks

 

[kingpb]

A simple example should help:
View attachment 434

So, in your case, they are saying the relay was tested at 100% of the motor FLA. To answer your question, 5.5 pu would then be 550% of rated motor current.

For more in depth knowledge, any good power system analysis book should discuss per unit.