Grounding; Connection Overview - Victron energy SmartSolar MPPT 150/70 Manual

4.4. Grounding

Battery grounding
The solar charger can be installed in a positive or in a negative grounded system.
Apply a single ground connection, preferably close to the battery, to prevent system issues or ground loops.
PV array grounding
The positive and negative of the PV array should not be grounded.
Ground the frame of the PV panels to reduce the impact of lightning.
Do not connect the solar charger to a grounded PV array. Only one ground connection is allowed, and this should be near the
battery.
Ground fault detection
The solar charger does not have internal ground fault protection.
The USA National Electrical Code (NEC) requires the use of an external ground fault protection device (GFPD).
The system electrical negative should be bonded through a GFPD to earth ground at one (and only one) location.
When a ground fault is indicated, battery terminals and connected circuits may be un-grounded and
hazardous.

4.5. Connection overview

TR model.
70A MC4 model.
85A or 100A model.
Page 13
MPPT solar charger manual
Installation