ABB REF615 Applications Manual page 153

1MRS756378 D
REF615
Application Manual
to turn the directional characteristic, if the expected fault current angle does not
coincide with the polarizing quantity to produce the maximum torque. That is,
RCA is the angle between the maximum torque line and polarizing quantity. If the
polarizing quantity is in phase with the maximum torque line, RCA is 0 degrees. The
angle is positive if operating current lags the polarizing quantity and negative if it
leads the polarizing quantity.
Example 1.
The "Phase angle" mode is selected, compensated network (φRCA = 0 deg)
=> Characteristic angle = 0 deg
GUID-57B7D22F-221A-480D-9145-614002A423A2 V1 EN
Figure 69: Definition of the relay characteristic angle, RCA=0 degrees in a
compensated network
Example 2.
The "Phase angle" mode is selected, solidly earthed network (φRCA = +60 deg)
=> Characteristic angle = +60 deg
Section 5
Protection functions
147