A solar combiner box is generally identical to an electrical junction box which houses several wires and cables and joins those connections tightly through different ports of entry.
As the name suggests, you use the solar combiner box to bind multiple strings of photovoltaic (PV) modules into one standard bus. The fibers are subsequently attached to the PV inverter.
According to Northern Arizona Wind & Sun, for solar combiner boxes between 12 and 48 volts, it’s a must to use breakers in place of fuses. The latter is mandatory for higher-voltage systems beyond 48 volts for either battery or grid-tie.
Through this guide, you can become familiar with the steps on the proper way to wire a solar combiner box to work with your solar panels.
What’s Inside a Solar Combiner Box
Before you proceed with the wiring, accustom yourself first and observe the inside of your solar combiner box.
In most cases, you will see a particular numbered pair of MC4 connectors for solar panel input connected to the same number of circuit breakers inside. The sole purpose of a circuit breaker in a combiner box is damage prevention. These numbers may vary depending on the model of the solar combiner box.
For instance, a six-branch solar combiner box means it features six pairs of MC4 connectors for connecting your solar panel to them. Other combiner box models feature an anti-thunder module that certainly protects the device from high-voltage lightning.
If your combiner box includes this module, it’s always best practice to check its light indicator once the thunderstorm subsides so you can determine whether a replacement is necessary.
In some combiner boxes, you will see a blanket breaker with a switch. This specified breaker allows you to control the entire solar combiner box.
The Components Needed
Once you are ready, put the solar combiner box in place and prepare the following parts:
A solar battery bank (lead-acid, lithium-ion, etc.)
A solar charge controller
A solar panel
A working, direct current (DC) lamp with a switch
The Wiring Procedure
Mount the solar charge controller on top of the solar battery bank. Depending on the model, fasten one end of both positive and negative wires with screws to the correct nodes on the charge controller.
With both wires attached to the charge controller, join the other end of those cables to the appropriate nodes of the battery bank using a positive-to-positive and negative-to-negative connection. It is best to refer to solar PV combiner wiring diagrams for more details.
Plug the solar panel wire into a single pair of MC4 connectors on the combiner box.
Connect the hurting wire adjacent to the blanket breaker via the output connector. Fasten it with screws.
Pass the positive and negative output wires through the holes labeled DC Output. Connect these output wires to the blanket breaker using screws.
Wire both the solar combiner box and the solar charge controller together. Make sure that the wires do not mix up with each other.
Connect the DC lamp to the solar charge controller with a screw.
Turn on the lamp switch to test the functionality of your setup.
Finally, you know how to wire a solar combiner box correctly. With a solar combiner box, you can maximize your solar panels’ power and ensure their reliability and efficiency.