Instruction Manual

Grounding
975-0400-01-01 Revision H 2–11
This manual is for use by qualified personnel only.
Installing a Positive-Grounded Battery System
The solar charge controller’s internal design has a built-in fuse—rated at 1 A,
600 V—which grounds both the PV negative and battery negative conductors
and provides PV ground-fault protection (PVGFP) to the system.
To avoid a short circuit, ground fault protection must be disabled before
grounding the positive battery terminal for negative voltage reference. Disabling
the PVGFP circuit in this way opens the negative-to-ground bond within the unit,
allowing for a positive battery ground connection.
If PVGFP is required, install an external protection circuit that is compatible with a
positive-grounded battery system.
Because there is no isolation between the battery and the PV array, this positive-
grounded battery configuration will bias the PV array terminals and the internal
auxiliary lines to –Batt V with respect to chassis ground.
For example, using a 100 VOC PV array and a 60 V battery bank, grounding the
positive battery terminal will make PV(–) sit at -60 V and PV(+) at +40 V. Aux(–)
will be biased at -60 V and Aux(+) at -45 V.
Figure 2-7 PV Negative Ground Jumper Location
Enabled Disabled
DANGER
ELECTRIC SHOCK AND FIRE HAZARDS
PV array terminals and auxiliary terminals must not be grounded in the
installed system.
Failure to follow these instructions will result in death or serious injury.