MLT Inverters Nomad 80, User Manual, Page: 33 / 44

8. Ground Fault Detector Interrupter (GFDI)
A ground fault is the undesirable condition of current
flowing through the grounding conductor. The cause of
this undesirable current flow is an unintentional electrical
connection between a current-carrying conductor in the
PV system and the equipment grounding conductor.
This can create a number of hazards since the normally
grounded current-carrying conductor may no longer be at
ground potential. The Nomad physically disconnects the
PV-panels to ensure site and operator safety.
The Nomad can be configured to detect ground faults on
both positively and negatively grounded photovoltaic
arrays as well as negatively grounded battery banks.
The Nomad GFDI works by checking if there is a voltage
difference between the
Fuse + and Fuse - points. If a
ground fault exists, a current will flow through the ground
fuse causing the fuse to blow (at 600mA). Once the fuse
blow the voltage difference is detected and the Nomad will stop operation and display a warning
message indicating that a ground fault was detected.
8.1 Selecting ground fault reference
After removing the cover from the Nomad, use the
enclosed two jumpers to select the relevant four pins as
shown below.
Only bridge one of the selection strips.
Ensure that the GFDI option is enabled on the MPPT Settings configuration screen (see page 26).
Caution: Only select one of the following configurations for the Ground Fault Detector
Interrupter. Selecting more than one configuration will results in equipment damage
and is a safety risk.
8.1.1 Battery Positive
Select this option if your battery bank needs to be positively grounded.
8.1.2 Photovoltaic/Battery Negative
The most common type of solar panel is a negatively grounded panel. Select this option if your solar
panel needs to be negatively grounded.
PV1+
BAT-/PV-
BAT+
FUSE+
FUSE-
600
mA
Jumpers
PAGE
32
NOMAD USER MANUAL