Thermal Overload Protection Mpttr - ABB RELION 630 Series Applications Manual

Section 3
REM630 variants
3.3.6.2
50
disturbance recorder. An internal blocking signal available from the function
INT_BLKD is connected to the disturbance recorder.
GUID-CC6EA594-91F9-46CA-9E59-434E2680A9B0 V2 EN
Figure 18: Motor load jam and differential protection

Thermal overload protection MPTTR

The three-phase thermal overload protection function is designed to be used for
protecting electric motors from overheating. The function calculates the thermal level
on the basis of the measured motor load current, rated motor current, and calculated
negative sequence current.
When the thermal level of the motor exceeds a predefined limit, the function generates
a thermal overload alarm. If the thermal content continues to rise and reaches 100
percent, the function block generates a trip command to stop the motor. To prevent
successive restarting of the motor when the motor temperature is high, restarting of the
motor is inhibited if the thermal content exceeds the set restart inhibit level. However
it is possible to start the motor in case of an emergency. The set of three phase currents,
I3P, is connected to the inputs.
1MRS756785 G
REM630
Application Manual