Electrical Connections - Victron energy MPPT 150/70 Manual

Apply a single ground connection, preferably close to the battery, to prevent system issues or ground loops.
Chassis grounding
A separate ground path for the chassis ground is permitted because the chassis is isolated from the positive and the negative
terminals.
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 on 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. Electrical connections

Make all electrical connections in the following order:
• Confirm correct battery polarity, then connect the battery (this will allow the solar charger to recognize the system voltage).
Torque moment 2.4Nm.
• Connect the remote on/off terminal (if applicable).
• Connect the programmable relay terminal (if applicable).
• Connect the VE.Direct communication cable (if applicable).
• Connect the VE.Can communication cable and VE.Can terminator (if applicable).
• Confirm correct PV polarity, then connect the solar array.
Torque moment TR model 2.4Nm
If accidentally connected in reverse polarity, the PV voltage will drop and the controller will heat up but will not charge the
battery.
• In case a MPPT WireBox is used:
First: Secure all electrical cables as indicated in the WireBox installation instructions
Then: Place the WireBox plastic cover over the solar charger connection area and secure it.
See below figure for an example of the solar charger connections:
Page 12
MPPT solar charger manual
Installation