Solar Combiner Box: What Is It?



Why add to the cost of your already pricey solar power system by adding yet another component? You might wish to avoid omitting the solar combiner box from a reliable solar combiner box manufacturer. The combiner box is relatively inexpensive in comparison to all of the other pricey equipment, but it provides your system with numerous additional benefits.

Solar combiner boxes combine incoming energy into a single main feed, which is then distributed to a solar inverter. Through wire reductions, labor and material expenses are reduced. Overcurrent and overvoltage protection are built into solar combiner boxes to improve inverter protection and dependability.

Let’s have a look at what a combiner box is and the role it plays in your solar system.

What Is a Solar Combiner Box

Ground fault Solar combiner box
Source: Pinterest

The conversion of light into power in a power supply box is known as photovoltaics (PV). Semiconducting materials with a photovoltaic effect are used to achieve this. A photovoltaic array, often known as a solar array, is a cluster of solar modules that are linked together. These modules must be linked together to generate enough power to appropriately meet the needs of a home or company.

Multiple solar modules are joined in a string in a huge solar photovoltaic array. The voltage levels are improved to make them suited for the inverter. After that, several strings of solar modules are combined. The string output currents are multiplied to bigger levels for input into the inverter as a result of this.

Solar photovoltaic array combiners (solar panel combiner boxes) are frequently used to connect several solar panels (or strings of panels) to a single bus. They’re essentially junction boxes that are specifically designed for the wiring types seen in PV systems. Array combiners are often used in bigger systems, although they can also help with wiring, monitoring, and future troubleshooting in small PV systems.

For 12 to 48-volt array combiners, we recommend utilizing breakers rather than fuses. Fuse boxes are usually necessary for higher voltage systems exceeding 48 volts, whether they be battery or grid-tie.

What Is the Function of a Solar Combiner Box?

Solar combiner box 1
Source: Pinterest

The combiner box’s function is to combine the output of multiple solar strings. The output of the fused inputs is merged onto a single wire that connects the box to the inverter, and each string conductor lands on a fuse terminal. This is the most basic kind of combiner box, however, once you have one installed in your solar project, it usually comes with additional functions. Additional equipment includes disconnect switches, monitoring equipment, and remote rapid shutdown devices.

It’s similar to a junction box, which is an electrical enclosure that securely connects several wires and cables via different entrance points. For connection to the inverter, a solar combiner box combines the output of multiple strings of PV modules. It usually houses many strings’ input overcurrent protection fuse assemblies. The number of strings might be ranging from three to fifty-two.

Other components that can be included in a solar combiner box include string monitoring hardware, surge protecting devices, and DC disconnects. Selecting the best solar combiner box necessitates a thorough grasp of the task site and the level of difficulty. You should also be familiar with the other components and how they interact with the combiner.

Factors to Consider When Choosing a Combiner Box

Simple photovoltaic power system for remote home system
Source: Pinterest

Enclosure– Most solar combiner boxes are housed in exterior enclosures. NEMA 3R is the bare minimum, while NEMA 4 steel and NEMA 4X non-metallic enclosures are more prevalent. You’ll want to consider the weather. It’s a good idea to incorporate a breather or condensation vent in regions where high humidity or frequent fluctuations in humidity are common. This will allow the enclosure’s pressure to be equalized. Water molecules are likewise kept out of the solar combiner box.

Choosing the proper solar combiner box often boils down to cost and availability. An off-the-shelf solution may be ideal if you’re installing your box in a residential building. They frequently provide a variety of possible setups. The customization function allows you to save time and money by preventing you from making unneeded purchases. Although the enclosure is usually one of the more expensive components of a solar combiner box, the box needs to provide long-term service.

Where Should a Solar Combiner Box Be Mounted?

combiner box
Source: Pinterest

Your solar combiner box should ideally be installed on a north-facing wall with some shade. This reduces the quantity of direct sunshine it is exposed to. Long durations of sun exposure, as you might expect, can raise the temperature of the internal combiner. The components in the box’s effectiveness and lifespan may be harmed as a result of this. It’s also worth noting that the effectiveness of the box might depend on the power distribution box manufacturer’s efficiency.

Air volume and surface area are increased in larger enclosures. This is useful for keeping the interior components cold. Larger enclosures can make field-wiring much easier by providing more space to work in during installation and maintenance.

Between the solar panels and the inverter should be the combiner box. It can reduce power loss when properly positioned in the array. The importance of location in terms of pricing can’t be overstated. Because a combiner in a less-than-ideal location may result in increased DC BOS expenses due to voltage and power losses, placement is critical. It’s only a few cents per watt, but it’s critical to get right.


Please don’t hesitate to contact us if you have any questions regarding solar combiner boxes. It is our pleasure to supply you with high-quality products and information at Eabel.

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One Response

  1. Dear Sir,
    Thanks for this article.
    May I know which standard highlight the benefit of having a DC combiner box?

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