EN
132
8.12 Verification of ground leakage
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.
8.12.1 Behaviour of a system without leakage
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:
Voc
V
t
+Vs
-Vs
NOTE –
D
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:
Volt
(+)
(-)
8.12.2 Behaviour of a system with leakage
If the voltage measured between one of the two poles and ground does not tend to 0V and stabilizes on a value, there is a ground leakage
from the PV generator.
Example: When the measurement is made between positive pole and ground, a voltage of 200V is measured.
V
200 V
300 V
t
