SolaX X3-PRO-15K-G2 Three-phase Inverter 15 kW

The SolaX X3-PRO-15K-G2 inverter is a 15 kW three-phase string photovoltaic inverter for workshops, farms, hospitality facilities and large residential systems. It is the size where the X3-PRO G2 range changes character: efficiency increases, forced ventilation is introduced and, above all, it exceeds the regulatory threshold that triggers the need for an interface panel.

Beyond 11,08 kW: what changes in the connection procedure

With 15 kW nominal power and 16,5 kVA maximum apparent power, the system exceeds the 11,08 kW threshold required by CEI 0-21. From this point on, the interface protection integrated in the inverter is no longer sufficient: an interface panel with SPI relay, an external interface device (DDI) and the test report to be attached to the connection documentation are required. This must be included in the quotation together with the inverter, not discovered on site: it amounts to several hundred euros and is an item the distributor checks.

SolaX X3-PRO-15K-G2 technical specifications

Two MPPTs for 22,5 kWp: the design constraint

The 15 kW accepts up to 22,5 kWp of photovoltaic array but manages them with only 2 MPPT trackers, 2 strings each and 32 A per tracker. This is about 50 modules of 450 Wp distributed over a maximum of four strings: it means long strings, therefore high voltages, and above all only two independent orientations. On a dual-pitch roof it is perfect; on a fragmented roof or one with partial shading on different sides, it is worth considering a 3 MPPT size or two smaller inverters.

Forced ventilation: where to install it

From 15 kW upwards, SolaX moves away from natural cooling and adopts smart ventilation, with fans that activate only when needed. The benefit is power density with the same footprint: the same enclosure as the 10 kW, with 5 kW more. The cost is acoustic emission, which rises to below 55 dB compared with 35 dB for the lower size, and the presence of moving parts that need to be cleaned periodically. In a technical room or on an external wall it is not a problem; under a bedroom window, it is.

Frequently asked questions

Do I need to install the interface panel with the SolaX X3-PRO-15K-G2?

Yes. By exceeding 11,08 kW, CEI 0-21 requires a panel with interface protection relay, external interface device and test report to be attached to the connection application. The protection integrated in the inverter does not replace these components above the threshold: they must be planned at the quotation stage together with the inverter.

How many modules are needed to make use of the 15 kW?

To operate close to nominal power, at least 15 kWp of modules are needed, about 33 panels of 450 Wp. The recommended limit is 22,5 kWp, equal to about 50 modules: a 150% oversizing that makes sense on roof pitches not perfectly oriented to the south, where peak power is never truly reached.

Can I connect three different orientations to the X3-PRO-15K-G2?

No, not independently. The inverter has 2 MPPTs, so it manages two groups of modules with different tilt or orientation. A third orientation would have to be combined with one of the two, with a loss of yield during the hours when the roof pitches do not operate together. For three exposures, a 3 MPPT size or two separate inverters are required.

How noisy is it compared with the 10 kW model?

The 15 kW uses smart ventilation and has a typical acoustic emission below 55 dB, compared with 35 dB for the naturally cooled 10 kW. The fans run only when the internal temperature requires it, therefore during full production hours. In a technical room, garage or on an external wall the difference is irrelevant; in a living area it should be considered.

Can the X3-PRO-15K-G2 limit grid feed-in?

Yes, export control is integrated and is activated by connecting an energy meter or CTs at the point of connection. Any feed-in limit can be set, down to zero export, which is required in some commercial configurations or when the available import power is lower than the power produced.