5-148 M60 Motor Protection System GE Multilin
5.6 GROUPED ELEMENTS 5 SETTINGS
5
Figure 5–56: STANDARD MOTOR CURVES
During the interval of discontinuity, the longer of the two trip times is used to reduce the chance of nui-
sance tripping during motor starts.
In some applications, the shape of the motor thermal damage curve substantially deviates from the standard. Further-
more, the characteristics of the starting (locked rotor and acceleration) and running thermal damage curves may not
correspond smoothly. In these cases, it may be necessary to use a custom curve so the motor can be started success-
fully and used to its full potential without compromising protection. For these conditions, it is recommended that the
OF x FLA
8xOFxFLA
x1
x15
100000
10000
1000
100
10
1.00
0.10 1.00
Multiples of Pickup ( Pickup = OF x FLA)
Time To Trip in Seconds
10 100
833003A2.CDR
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