Evaluation Of Transient And Arcing Faults - Protrol IPC4020 Manual

Evaluation of Transient and Arcing Faults

An arcing earth fault is characterized by its transient nature. It extinguishes and then returns with a new
transient after a certain time or with a certain frequency. If the time delay is short enough, a single
transient may be sufficient for the detector to go to the TRIP state. If an error occurs and the detector
reaches the START state, the reignition timer is started. If the fault returns within the set reignition time,
the detector will indicate TRIP immediately when the START state is reached. Thus, it does not wait for the
normal time delay between START and TRIP to expire. Two consecutive starts within a certain time is
evaluated as an arcing fault. The method ensures that an arcing error does not start and reset repeatedly.
2,5
2
1,5
1
0,5
0
-0,5
-1
-1,5
10
8
6
4
2
0
Figure 9. Earth fault with arcing characteristics – after the second "START" the detector progresses immediately to
state TRIP.
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Reignition time
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