ABB REM 610 Technical Reference Manual page 129

1MRS 755537
Motor protection Relay
Technical Reference Manual
The pickup value of element 51N is calculated as follows:
5A
× ×
20% 1650A --------------- -
2000A
Thus, 51N = 16% and the 5A input is used.
The operate time of the ground-fault element is set to 50 ms when the network is
solidly grounded.
If the drive is contactor controlled, refer to section Protecting a contactor controlled
motor.
×
16% 5A
=
REM 610
129