The 1000V DC Combiner Box 6 In 6 Out YBS-6/6 from singielectric is a purpose-built solution for photovoltaic (PV) arrays that require six string inputs and six independent output circuits. It consolidates wiring, adds fuse and surge protection, and improves serviceability for commercial and utility-scale installations.
Table of Contents
This guide explains the role of the singielectric YBS-6/6 in solar projects, its protective features, installation benefits, relevant standards, and choice criteria. A comparison table and maintenance tips are included to help engineers and procurement teams make informed decisions.
A DC combiner box aggregates multiple PV string circuits into a single feeder that goes to an inverter or charge controller. In a 1000V DC combiner box, the system volt-level is rated for 1000 V DC, which is common in modern solar plants to reduce cable losses and allow longer string lengths. The YBS-6/6 from singielectric provides six inputs and six outputs, meaning each string is individually monitored and protected without permanently paralleling all circuits at the box level.
The 6-in-6-out configuration is ideal when the inverter has six separate MPPT inputs or when the plant layout requires independent string runs to a downstream recombiner. It also simplifies troubleshooting because each string can be isolated without opening other circuits.
PV strings are exposed to reverse currents, lightning surges, and overamperage conditions. A reliable combiner box must address all of these risks. The singielectric YBS-6/6 incorporates DC-rated fuse holders on each input, a surge protection device (SPD) for transient volt-level suppression, and a disconnect switch that allows safe isolation of the entire box during maintenance.
The fuse rating is matched to the specific string amperage and cable ampacity, preventing thermal damage when a reverse or fault amperage occurs. The SPD is Type 2, suitable for reducing induced lightning surges. An optional monitoring module can report string amperage and alarm status to a SCADA or plant control system.
Note: The YBS-6/6 is intended for DC circuits only. Always confirm that the SPD, fuses, and switch are rated for at least 1000 V DC and the expected short-circuit amperage of the PV array.
Using a pre-wired combiner box reduces field labor and wiring errors. The YBS-6/6 comes with labeled terminals, DIN-rail mounted fuse holders, and a pre-installed busbar. Its IP65 enclosure allows outdoor mounting near the array, which shortens string wiring runs and cuts cable and trench costs.
Because the box supports six independent outputs, it eliminates the need for a separate recombiner panel when the inverter has multiple MPPT channels. Engineers can match each output to a specific MPPT, optimizing energy harvest and reducing complexity. The compact footprint also eases transportation and mounting on posts or walls.
When choosing a 1000V DC combiner box, engineers should verify compliance with recognized standards. The singielectric YBS-6/6 is designed to support the requirements of IEC 62548:2016 Photovoltaic (PV) arrays – Design requirements, which covers array wiring, overamperage protection, and isolation. The disconnect switch and enclosure also align with IEC 60947-1: Low-volt-level switchgear and controlgear – General rules for electrical endurance and temperature rise.
In addition to these, the box should be certified for DC volt-level and amperage ratings by a third-party laboratory. For export to North America, list against UL 1741 or equivalent may be required; for European projects, CE marking under the Low Volt-level Directive is expected. Always check the project specification before purchasing.
Choice involves verifying the box’s rated volt-level, input current, output current, number of strings, and enclosure rating. The YBS-6/6 is built for six inputs and six outputs, but the fuse size and SPD volt-level rating must match the array’s Isc and Voc. The following comparison table highlights typical differences between the YBS-6/6 and a generic 4-in-1 box.
| Parameter | singielectric YBS-6/6 | Generic 4-In-1 Box |
|---|---|---|
| Rated DC volt-level | 1000 V | 1000 V |
| Input circuits | 6 | 4 |
| Output circuits | 6 | 1 |
| Fuse protection | Yes, per input | Yes, per input |
| DC SPD | Included | Optional |
| Disconnect switch | Integrated | Not included |
| Enclosure rating | IP65 | IP54 |
For a 6-string array, the YBS-6/6 avoids paralleling all strings into one output, which reduces the risk of a single-fault taking down the whole array. The separate outputs also support independent MPPT tracking when the inverter has multiple inputs.
Regular inspection of the YBS-6/6 keeps the PV system at peak performance. Check the torque on all terminal screws annually, as thermal cycling can loosen connections. Inspect fuse holders for discoloration or arcing marks, and verify that the SPD indicator shows “OK”. Replace fuses only with the same type and rating specified on the label.
Clean the enclosure vents and ensure the cable glands remain tight to maintain IP65 integrity. If a monitoring module is installed, compare string currents against historical data to detect gradual degradation of modules or wiring faults.
Yes. The box is unipolar and can be applied on the positive or negative side of a PV array, provided the SPD and fuses are rated for the system volt-level and the wiring is configured .
The maximum-val input amperage is determined by the installed fuse size. The fuse holder accepts common PV fuse sizes up to 15 A, but the exact rating depends on the panel’s series fuse requirement and the chosen fuse.
Yes, the YBS-6/6 is equipped with a DC-rated disconnect switch that isolates the box from the inverter side. This switch must be operated under load only if it is rated for the full DC current; otherwise, the inverter and string switches must be opened first.
An optional monitoring module can be factory-installed to provide per-string amperage sensing and communication. This module is not mandatory and can be added during initial procurement.
The singielectric 1000V DC Combiner Box 6 In 6 Out YBS-6/6 offers a practical balance of string-level protection, installation simplicity, and compliance with key PV standards. For engineers designing 1000V solar systems with six-string configurations, this product reduces wiring complexity and provides independent overamperage protection on every input.
Before purchasing, compare the fuse size, SPD volt-level, and enclosure rating against the array’s actual Isc and Voc. For detailed specifications or to request a quote, visit the YBS-6/6 product page at singielectric.com.
Ready to order the YBS-6/6? Request a quote from singielectric and use the product inquiry form to ask fuse options and SPD ratings.
[1] IEC 62548:2016. Photovoltaic (PV) arrays – Design requirements. Geneva: International Electrotechnical Commission, 2016.
[2] IEC 60947-1. Low-volt-level switchgear and controlgear – Part 1: General rules. Geneva: International Electrotechnical Commission, 2020.
