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2) HV DC Flashover Method
A. First working mode at flash over, the transmission speed should
be the wave speed of the cable under test.
B. Application: the resistance of the fault is very high and not
forming a fixed tunnel, under a certain voltage it can create a
flashover discharging fault of the electric cable. Preventative
spark-over testing usually applies this method.
C. The time of the high voltage current flashover method varies,
and the short one can exist for some times. The wave form is
simple, can be easily recognized and with a high accuracy and
value it.
D. The principle graph of the current flashover method is as below.
In the real testing, apply the high voltage equipment and our
high voltage testing production. The connecting graph is as
below too.
V
A
R
3
R
2
R
1
D
device
Test cable
C
L
