Basler Electric BE1-11m - Manual (Page 562)

550 9424200996 Rev L
Set the 49RTD-1 protection element as shown in Figure 381 to protect the stator winding insulation.
Voting is set to 2, meaning at least 2 RTDs must be at 155
°C or higher to result in a trip. A delay is not
required for the reason that temperatures change slowly because of the large motor thermal mass.
Figure 381. Protection, Thermal, Resistance Temperature Detector (49RTD-1) Screen
Set the 49RTD-2 protection element as shown in Figure 382 to protect the motor bearings. The maximum
bearing temperature of 95
°C is supplied in the motor manufacturer data. Voting is set to 1, which provides
a sensitive bearing overtemperature trip. Only 1 RTD must be 95
°C or higher to result in a trip.
Figure 382. Protection, Thermal, Resistance Temperature Detector (49RTD-2) Screen
Protection - Current
Five instantaneous overcurrent elements, one current differential element, and one instantaneous
undercurrent element are used in this settings example.
Instantaneous Overcurrent (50-1) - Short-Circuit Protection
Use the 50-1 protection element to protect the motor stator windings for a short circuit. Set the pickup as
low as possible without causing a trip to occur during motor starting. The pickup setting is derived using a
dc offset of 1.7, 125 percent of LRA, and a BE1-11m pickup tolerance of 2 percent. CTR is the CT ratio.
See Equation 63.
Settings Calculation Examples BE1-11m