How to wire the system
The first component we are going to wire is the Charge Controller. At the bottom of the Charge Controller there are 3 signs in my charge controller. The first one from the left is for the connection of the Solar Panel having positive (+) and negative (-) signs. The second one with plus (+) and minus (-) signs is for the Battery connection and the last one for the direct DC load connection like DC lights.
Wiring of the charge controller
As per the charge controller manual always connect the Charge Controller to the Battery first because this allows the Charge Controller to get calibrated to whether it is 12V or 24V system. Connect the red (+) and black (-) wire from the battery bank to the charge controller.
Note: First connect the black / negative wire from the battery to the charge controller’s negative terminal, then connect the positive wire.
After connecting the battery with the charge controller you can see the Charge Controller indicator led lights up to indicate the battery level.
After connecting this, inverter terminals for battery charging is connected to corresponding positive and negative terminals of the battery.
Inverter AC output
Now you have to connect the solar panel to the charge controller. At the back side of the Solar Panel there is a small junction box with 2 connected wires with positive(+) and negative (-) sign. The terminal wires are normally smaller in length.
Solar panel junction box wiring
To connect the wire to the charge controller you need a special type of connector which is commonly known as MC4 connector. See the picture below. After connecting the solar panel to the charge controller the green led indicator will light up if sunlight is present.
An MC4 connector
Note: Always connect the Solar Panel to the Charge Controller while facing the Panel away from the sun or you may cover the panel with a dark material to avoid sudden high voltage coming from the solar panel to the Charge Controller which may damage it.
Safety: It is important to note that we are dealing with DC current. So the positive (+) is to be connected to positive (+) and negative (-) with negative (-) from Solar Panel to Charge Controller. If it gets mixed up, the equipment can break and may catch fire. So you need to be extremely careful when connecting these wires. It is recommended to use 2 color wires i.e. red color for positive (+) and black color for negative (-). If you don’t have red and black wire you may wrap red and black tape at the terminals.
Connect the DC load or DC light as the final step.
Additional Protection: Though charge controller and inverter have inbuilt fuses for protection, you can put switches and fuses in the following places for additional protection and isolation.
1. In between solar panel and charge controller
2. In between charge controller and battery bank
3. In between battery and inverter
After wiring all components the off-grid solar system is ready for use.