Siemens siprotec SJ62 User Manual page 162

Figure 2-52 Temperature curve at the rotor and the thermal profile during repeated start-up attempts
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66)
Although the heat distribution on the rotor bars may severely differ during motor start-
ing, the different maximum temperatures in the rotor are not pertinant for motor restart
inhibit (see Figure 2-52). It is much more important to establish a thermal profile, after
a complete motor start, that is appropriate for the protection of the motor's thermal
condition. Figure 2-52 shows, as an example, the heating processes during repeated
motor starts (three starts from cold operating condition), as well as the thermal profile
in the protection relay.
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