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Control unit for solar operation
The control unit for solar operation J355 is installed in the technical cabinet. The control unit is the link between
the 12 V electrical system and the solar panel. Even if the battery master and isolator switch E74 for the
additional battery is in the “Off” position, the solar installation continues to charge or support the additional
battery.
Due to the different solar panel areas on the Grand California 600 (104 Wp) and the Grand California 680
(174 Wp), different solar controllers are installed:
- Grand California 600: MPP 165 Duo Digital
- Grand California 680: MPP 250 Duo Digital
They differ mainly in the maximum possible charging current. AGM batteries are used as starter and second
batteries in the Grand California. The battery type is set to AGM2 14.8 V on the solar controller. This also
corresponds to the charging voltage of the on-board charger.
The control unit for solar operation automatically determines the maximum power point (MPP) of the solar
modules several times per second. It then transforms the excess voltage of the solar module to a higher charging
current for the battery. The meanings of the monitoring LEDs are described in the manufacturer’s instructions.
Wiring
*MPP – maximum power point
Control unit for solar operation J355
Solar panel
Additional battery
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