Kewtech KT64, Instruction Manual, Page: 20 / 44

17
8 . 1 . 2 Capacitive Current
The insulation between conductors which have a potential difference between
them behaves as the dielectric of a capacitor, the conductors acting as
the capacitor plates. When a direct voltage is applied to the conductors, a
charging current will flow to the system which will die away to zero (usually
in less than a second) when the effective capacitor becomes charged. This
charge must be removed from the system at the end of the test, a function
which is automatically performed by the KT
64 . If an alternating voltage
is applied between the conductors, the system continuously charges and
discharges as the applied voltage alternates, so that there is a continuous
alternating leakage current flowing to the system.
8 . 1 . 3 Conduction Current
Since the insulation resistance is not infinite, a small leakage current flows
through the insulation between conductors. Since Ohm's Law applies, the
leakage current can be calculated from
applied voltage (V)
Leakage current (
μ
A)
＝
insulation resistance (M
Ω
)
Fig. 12
Fig. 13
Insulation