A solar combiner power box is of immense utility when we want to derive good power and voltage from a combination of solar cells and panels. An array consisting of a large number of solar photovoltaic cells are connected in the form of stringsto a combiner box, to ensure that the cumulative voltage reaches to the desired level. However, a need for a solar combiner box for connecting cells only arises in plants with a capacity of 500 kilowatts (kW). From 3 to 52, there can be a great many strings connected through a combiner box that also hasthe fuses that provide for input overcurrent protection. The combiner boxes have evolved and are now even more secure and useful. They may consist of the surge protection devices,DC disconnects, and even the monitoring hardware now.
Evaluating a Solar Combiner Box
A solar combiner box for the solar cells and strings may be evaluated based on many different criteria. The first of these criteria may be the housing or the enclosure itself. The enclosure should be able to protect the combiner box's internal components against the external and other elements that may deteriorate their life. Excessive heat and high temperatures, dust, moisture, and other environmental/internal factors may affect the life of the components placed within the combiner box. The National Electrical Manufacturers Association (NEMA) has the rating scale following which a combiner box may be evaluated for its protection to the internal components and the threats it can withstand. A NEMA rating of 3R is considered to be the base requirement. The rating of 4 or 4X is also appropriate for these enclosures. X here symbolizes anti-corrosive strength. Therefore, the 4X enclosure rating ensures that the box protects components against dust and moisture and can be used in environments where the corrosive elements are present. Sometimes a breather or condensation vent may also be added and integrated into the combiner box built if the region has high humidity. These vents do not disturb pressure equalization but do not allow the water molecules to penetrate inside the combiner box.
The enclosure or body of the combiner box maybe it's most crucial component and also the priciest.Itlays a direct impact on the life of the combiner box's many different components and the entire assembly.
Temperature
Higher than usual or normal temperatures reduce the life of the components placed in the combiner box and its enclosure. Approaches and inclusions, including placement of vents, may provide for the regulation of temperature better. However, other factors, including color, size,and location of the combiner box, also affect the temperatures associated with it. When the combiner box is placed outdoors, it should be of a lighter color to absorb a lesser amount of solar heat and UV radiation. When the combiner box is placed on the north wall, it will absorb a lesser amount of heat, as it is less exposed to the direct sun rays. It will reduce the temperature within the combiner box. Also, when the combiner box has a large area, higher flow and movement of air inside and temperatures will be more normal. The larger size also provides more space for wiring and helps in easy maintenance. When you want to enhance your combiner box's life and the internal components placed in it, go for the ones that have larger than adequate size.
Output Wire Bend Radius
UL(Underwriters Laboratories) and NEC(National Electric Code)lay down the requirements and guidelines for the wire bend radius spacings. The adjacent and the opposite wall requirements of the spacings follow the lug's or terminal's size to which the output wire is landing. Larger lug sizes need larger spacings.
The best manufacturers and suppliers of enclosures and combiner boxes also provide affordable maintenance plans to ensure that you make the most value for your invested money.
