ABB RELION 670 Series Technical Manual page 596

Section 8
Current protection
block
IEC12000016 V1 EN-US
Figure 316: Representation of the rotor overload protection
Each of these five sub-blocks will be described in the following sections of this document.
Current measurement
Three phase currents are measured either on the high voltage side (HV) or on the low voltage side
(LV) of the excitation transformer, see Figure317.
590
Current
measurement
block
Alarm Ripple
Detection
block
Overload
characteristic
Undercurrent
protection for rotor
winding
1MRK 502 066-UUS B
Trip logic
IEC12000016-1-en.vsd
Technical manual