Siemens SIPROTEC 7UT613 series Manual page 209

Figure 2-94 Logic diagram of the unbalanced load protection - illustrated for IEC characteristic
Thermal Stage
Pickup, Warning
7UT613/63x Manual
C53000-G1176-C160-2
With the aid of the thermal stages the unbalanced load protection can be well adapted
to the thermal loading of the electrical motor rotor during asymmetric load.
The permissible continuous load imbalance is determined with the setting „I2 Permis-
sible". If this value is exceeded, it applies as "Pickup" for the negative sequence pro-
tection. At the same time this sets the alarm stage: After a set time „T WARN" has ex-
pired, a warning message „I2> alarm"is given.
2.8 Unbalanced Load Protection
209