Hybrid Solar Wind Turbine System
Electrical Distribution Parts
A combiner/circuit breaker box is a key piece of equipment that begins to bring the system production together that allows you to generate electricity. NEC (National Electrical Code) says that each series of strings of panels are to be wired to its own circuit breaker. Midnite Solar and OutBack combiner boxes make this task easy providing a breaker to turn off and on each string for any purpose. The combiner box is usually located directly under a ground mount array or on the wall directly below the roof-mounted solar array in conjunction with a locally supplied junction box at the edge of the roof Arran. (Transition to conduit down to the combiner in that circumstance.
Wire size and breakers are the final items in your hybrid solar wind design to consider, but no less important. To have a safe off-grid system, you will need to install breakers and choose the right size wire. If you select one of our pre-wired power systems with your kit, we do all the heavy lifting for you because right size breakers are pre-engineered and pre-wired into each of our power centers. You simply have to hang and connect it following our wire diagram which is supplied with all our kits. It is no accident you will only find Midnite Solar and OutBack combiner boxes built into our off-grid systems. They are reliable, UL listed and simple to install.
The distance between the combiner box, which is usually located near the solar panels, and the charge controller will be a factor in choosing the best string voltage for the charge controller and battery system. The higher the input voltage the smaller the wire can be for any given amount of power. For example, a system with a 12-volt battery and solar panels consisting of four 6.75 amp 12 volt DC nominal modules located at a distance of 40’ from the batteries could have the modules wired in series, parallel or series and parallel. Input design possibilities in this example are 12, 24, and 48 volts DC. If the panels was configured with the panels wired in parallel the input voltage would be 12 volts DC with an input current of 26 amps. The same panels wired in series would have an input voltage of 48 volts DC and an input current of 6.5 amps. In this example #1, the 26 amp 12 volts DC panels #1/0 wire, which is prohibitively expensive, would be required to limit voltage drop to 2% which is recommended for 12 volt DC systems. The same panels wired for 48 volts dc would only require a #8 wire. With the #8 AWG wire, the 12-volt dc panels would have to be within 7’ of the batteries. The distance that #8 wire can be used is over 5 times greater at 48 volts DC than 12 volts DC.
The amount of current (amps) traveling through any electrical circuit depends on the size of the wire (AWG), the voltage of the array or battery bank, and the one-way distance of the wire run. Lower AWG gauge wire has less resistance than larger gauge wire. The longer the distance of your wire run while using lower voltage the larger gauge wire you are going to need. That is the reason we highly recommend a 48VDC battery-based system.