Distance relay

[Mohammed Ahmed]

What if the question (in NCEES#521) asks about the time delay setting if we supposed it is not instantaneous type? how can we get impednece value if zone 1 is located within 15% of line impedence.

 

[RedRaider2020]

Under most circumstances Z1 operates instantaneously. If it is delayed you would need to know why it's being delayed. If it's coordinating with another relay or element then that information would need to be provided.

100%-15%=85% of line impedance = (0.217+j0.637)(.85) = 0.184+j0.539