SecSun UBM-57260 PV Combiner Box AC/DC 6kW 2 Strings
The SecSun UBM-57260 is an AC/DC combiner box (string box) for single-phase photovoltaic systems up to 6 kW with 2 independent strings at 1000 VDC: integrated DC and AC protections. IP65, class II, EN 61439 compliant.
The SecSun UBM-57260 is a pre-wired AC/DC combiner box (string box) for single-phase photovoltaic systems up to 6 kW with 2 independent strings at 1000 VDC. It groups into a single IP65 enclosure the disconnection and protection devices between the PV strings, the inverter and the grid.
Why 1000 VDC and two independent strings?
The 1000 VDC DC rating allows longer strings (more modules in series) than a 600 V box, and the two independent strings let you connect two separate MPPT inputs or two orientations while keeping each protected on its own. The box brings the string combination, disconnection and overvoltage/overcurrent protection together, pre-wired and certified to CEI EN 61439-1/2.
Technical specifications
| Model | SecSun UBM-57260 |
| Configuration | Single-phase, 6 kW, 2 independent strings |
| DC side | 1000 VDC; string fuse-disconnectors and surge arresters |
| AC side | Differential circuit breaker (RCBO) and surge arrester |
| Protection rating | IP65, insulation class II |
| Standard | CEI EN 61439-1/2 declaration of conformity |
| Dimensions | 622 × 340 × 161 mm (H×W×D) |
Frequently asked questions
What does a combiner box do?
It concentrates the disconnection and protection devices between modules, inverter and grid in one certified enclosure — DC and AC disconnectors, fuses and surge arresters — protecting the equipment and allowing the system to be isolated at a single point.
What is the difference from the 600 VDC version?
This box is rated 1000 VDC on the DC side, so it supports longer strings than a 600 V model. Choose according to the maximum string voltage (Voc at the lowest expected temperature) of your array.
Can it be installed outdoors?
Yes. The IP65 rating protects against dust and water jets; installation shielded from direct sunlight and extreme temperatures is recommended for longer service life.
Who should install it?
Installation and connection must be carried out by a qualified electrician, respecting polarities, tightening torques and the applicable regulations.
