Grounding - Victron energy MPPT 150/70 Manual

120 W 120 W
12 V 12 V
240 W
24 V
10 A
To help calculate the size of the PV array configuration use the
configurations:
PV array example 24V battery with 150V solar charger:
• Minimum number of cells in series: 72 (2x 12V panel in series or 1x 24V panel).
• Recommended number of cells for highest controller efficiency: 144 cells (4x 12V panel or 2x 24V panel in series).
• Maximum: 216 cells (6x 12V or 3x 24V panel in series)
PV array example 48V battery with 150V solar charger:
• Minimum number of cells in series: 144 (4x 12V panel or 2x 24V panel in series).
• Maximum: 216 cells (6x 12V or 3x 24V panel in series).
PV array example 48V battery with 250V solar charger:
• Minimum number of cells in series: 144 (4x 12V panel or 2x 24V panel in series).
• Maximum: 360 cells (10x 12V or 5x 24 panel in series).
Provide means to disconnect all current-carrying conductors of a photo-voltaic power source from all other
conductors in a building or other structure.
Be aware that at low temperatures and depending on local conditions and cell specifications the open circuit
voltage of a solar array may exceed the array's rated maximum open circuit voltage. In that case the number
of cells in series must be reduced.
A switch, circuit breaker, or other device, either AC or DC, shall not be installed in a grounded conductor if
operation of that switch, circuit breaker, or other device leaves the grounded conductor in an un-grounded
state while the system remains energized.
Do not use solar panels with optimizers.
For MC4 models: several of the solar charger's MC4 pairs may be needed to parallel solar panel strings. Be
aware that the maximum current through a MC4 connection cannot exceed 30A.
Use flexible multi stranded copper cable for the screw connections (Tr model). See chapter
precautions [1].

4.4. Grounding

Battery grounding
The solar charger can be installed in a positive or in a negative grounded system.
Page 11
MPPT solar charger manual
120 W 120 W
12 V 12 V
240 W
12 V
20 A
Examples of series, parallel and series/parallel solar arrays.
MPPT sizing
120 W 120 W 120 W
12 V 12 V 12 V
480 W
24 V
20 A
calculator. Alternatively, use one of these PV array
Wiring safety
120 W
12 V
Installation