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3) Impulse High Voltage Flashover Method
A. Application: the fault point with a high resistance but already
forms a fixed a tunnel in cable. The high voltage equipment’s
capacity is in limit, if the current can not reach the certain level, it
should apply flashover method. The fault which can not be tested
out by current flashover and impulse method, the method applies it
in theory.
B.As the same, it shuold check the switch whether on the position
of flashover and the high voltage testing equipment whether has a
good water resistance and voltage divider.
C.
Connect the devices as below. The ground line works as
8.2.6 and 9.3. The capacity in it is demanded higher than 1μF, the
withstand voltage should be in demand. The other demands are
as the same of the flashover method. The inductance usually uses
as in the device 2 or device 3. Or adjust the wave form according
to the length of the tested cable.
D.
Testing method: adjust the adaptor to rise the voltage to the
burn down of the tested staff. The gap of the spheres should
account to the resistance and whether the tested voltaeg could
V
A
R
3
R
2
R
1
D
device
Test cable
C
L
