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Evaluation Methods for Solar String Combiner Box

Oct. 13, 2021

In big solar photovoltaic (PV) arrays, multiple solar components are connected in collection to develop a string to increase the voltage to an ideal level for the inverter. Several strings of solar components are then combined in alongside increase the string outcome current to a greater level for input to the inverter. Combiner box supplier shares with you.

solar system

A combiner box is a tool that merges the outcomes of multiple PV components to an inverter. It is normally made use of in larger industrial and utility scale PV plants. The combiner box typically has several strings (from as couple of as 3 to as numerous as 52 strings) of input overcurrent defense fuse settings up and a combined bus of these inputs connected to a solitary primary outcome. Today's combiner boxes can also suit a number of various other elements of the station.


There are numerous crucial elements that need very close attention when defining or evaluating a string combiner box. The initial component is the room. A lot of string combiners are available in outdoor ranked rooms, normally NEMA 3R, 4 or 4X, with NEMA 3R being the minimum demand. A lot more normal today are NEMA 4 steel or NEMA 4X non-metallic rooms. In areas of high or changing moisture, you may want to think about including condensing or venting vents to equalise the stress in the enclosure but protect against water molecules from going into.

The housing is typically one of the much more pricey components in a string combiner, however it is necessary since it has a straight impact on the life of the combiner. The installing setting, dimension and also colour of the housing straight impacts the interior temperature. Lighter colours usually take in much less solar radiation than darker colours. Installation on a north-facing wall in the color is suggested, as direct sunshine can substantially raise the temperature of the interior combiner, reducing the reliability and life of the inner elements.

ZJBENY BHSA-8 600 or 1000V DC Arc Fault Circuit Interruption (AFCI) Combiner Box

Wire bend radius

Result wire bend radius is one more aspect to pay very close attention to when defining or evaluating string combiners.The NEC and UL have needs for cord bend distance spacing within string combiners. There are wall-to-wall as well as adjacent-wall bend radius demands, depending upon the dimension of the incurable or lug to which the outcome cord is attached. Bigger lugs require even more room.

In bigger utility-scale PV sites, several installers choose to make use of aluminium conductors for huge scale outcome lines from combiner to inverter as aluminium expenses are much less than copper - specifically when taking care of hundreds of feet of conductor. However, for comparable voltage declines, aluminium conductors require a bigger scale than copper of the same length, which requires using larger terminals or lugs inside the combiner.

Bending huge conductors in the field is time consuming and frequently a waste of product, so utilizing combiner styles that can be fired directly to the result terminals without bending can save installation time and also lower mechanical stress on the inner parts of the string combiner.

With more than 30 years experience in electrical industry, ZJBENY has developed world class solar DC components in a full range. We design, produce and market different voltage levels components and solutions for solar PV protecting. You can contact our experts to get the quotes and details.