ABB REM 610 Technical Reference Manual page 117

1MRS 755537
Motor protection Relay
Technical Reference Manual
Example 1
Start-up current of the motor
Start-up time of the motor
One hot start allowed
Ambient temperature
At an ambient temperature of 40°C the internal FLA equals the FLA of the motor.
Thus, the start-up current of the motor is 6.2 x the internal FLA.
The safe stall time setting is calculated or selected from the trip curves at prior load
1 x FLA. In the figure below, a safe stall time of 30 seconds is selected, permitting
a start-up time slightly longer than the one stated by the motor manufacturer; see the
figure below.
Fig. 5.1.2.2.-1 Selected safe stall time 30 s
Example 2
Start-up current of the motor
Start-up time of the motor
One hot start allowed
Ambient temperature
At an ambient temperature of 20°C the internal FLA is 1.09 x FLA of the motor.
Thus, the start-up current of the motor is 6.2/1.09 = 5.69 x the internal FLA.
6.2 x FLA
11 s
40°C
6.2 x FLA
11 s
20°C
REM 610
117