Verification Of Ground Leakage; Behaviour Of A System Without Leakage - ABB PVS-100 Product Manual

V
erification of ground leakage
B
ehaviour of a system without leakage
The internal resistance of the
voltmeter tends to zero the voltage
present on the PV generator due
to the capacitive effect.
How to make the measurement:
In the presence of anomalies or report of ground fault (where provided),
there may be a ground leakage from the PV generator (DC side).
To check this, measure the voltage between the positive pole and ground
and between the negative pole (of the PV generator) and ground using a
voltmeter whose input accepts a voltage sufficient for the dimensions of
the photovoltaic generator.
Due to the capacitive effect of the PV generator, during the first moments
that the voltmeter is connected between one of the two poles and ground,
it will measure a voltage of about Voc/2, which will tend to stabilize to
around 0V if there is no ground leakage, as shown in the graph below:
+Vs
Voc
-Vs
- 164 -
V
8 - Maintenance
t
(-)
(+)
Volt