Combiner Box vs Recombiner: String, Array and Terminology

String, array and recombiner: one vocabulary

The words string, array, and recombiner are used inconsistently across the PV industry. A string is a series connection of modules. An array is the broader DC collection, often several strings. A recombiner is an enclosure that groups already-combined DC feeds at a higher level, typically in utility-scale plants. None of these is a fixed product standard; they describe a wiring hierarchy. Use one term per level and avoid implying a single official taxonomy.

Where each term fits

The terms describe position in the hierarchy, not a competing set of device classes. Keeping the vocabulary consistent across drawings, the bill of materials, and the commissioning report prevents the common error of ordering a recombiner when a string combiner with more inputs would do, or the reverse.

• String combiner: collects individual series strings into one DC output.
• Array combiner: a looser name for the same function at array level.
• Recombiner: combines outputs of multiple string combiners, not single strings.

Why the confusion causes mistakes

Mixing terms leads to wrong sizing and wrong protection coordination. A box labeled recombiner may simply be a large string combiner with more inputs. Read the input count, the rated current, and the busbar rating instead of trusting the label. Confirm the approved NEUTRON model datasheet before assuming a function.

Selection should follow electrical ratings, not marketing names. Where a specific feature is claimed, verify it against the approved model's listed values and test reports.

Reading the rating plate

To avoid name confusion, read the rating plate rather than the category word. The numbers that decide the application are the number of string inputs, the maximum string current, the system voltage, and the busbar rating. A correctly specified string combiner and a correctly specified recombiner can belong to the same product family; the real difference is the aggregation level they serve, which the plate shows directly.

Selection without guessing

Choose by input count, string current, and system voltage, not by name. Use the configurator and the protection coordinator as planning aids, then verify against the approved model's listed values. A clear vocabulary reduces errors more than any single product label. Where a feature such as monitoring or a disconnect is required, confirm it is listed for the exact model rather than assumed from the category.

• Match the input count to the real number of strings.
• Match the busbar rating to the aggregated string current.
• Confirm system voltage and standard edition before ordering.