SolaX X3-PRO-25K-G2 Three-phase Inverter 25 kW

The SolaX X3-PRO-25K-G2 inverter is a 25 kW three-phase string photovoltaic inverter for industrial, agricultural and commercial systems. It is the model where the X3-PRO G2 range changes architecture: it moves from two to three MPPT trackers and maximum efficiency rises to 98,5%, the highest value in the entire series.

Three MPPTs: when they really make a difference

Up to 20 kW, the series works with 2 trackers, so only two independent orientations. The 25 kW has 3, with 2 strings each: six strings in total and three groups of modules that the inverter tracks separately. On a sawtooth industrial roof, on a hipped roof or on a system divided between an east-facing roof plane, a west-facing roof plane and a south-facing section, this translates into genuinely more energy collected, because each group works at its own maximum power point even when the others are shaded or out of phase. On a roof with only two slopes, however, the third tracker adds nothing and it is worth considering the 20 kW.

SolaX X3-PRO-25K-G2 technical specifications

What half a point of efficiency is worth on an industrial system

The jump from 98,3% to 98,5% maximum efficiency, and from 97,8% to 98,0% European efficiency, seems marginal. On a 37,5 kWp system producing around 45.000 kWh per year, it means a few hundred kWh recovered every year, throughout the system’s lifetime, with no additional costs. It is an advantage that adds to that of the three trackers, and it is why the 25 kW is often preferable to two 12 kW units for the same overall power.

Regulatory requirements and protections

At 25 kW, the system is well above the 11,08 kW threshold of CEI 0-21: an interface panel with SPI relay, external interface device and test report are required for the grid connection procedure. The agreed feed-in power and any requirements at the delivery point must be checked with the distributor. On the inverter side, a DC disconnector and Type II SPD on both sides are integrated; AFCI, protection against DC electric arcs, is available as an option and is recommended on large industrial roofs, where DC cable runs are long.

Frequently asked questions

How many MPPTs does the SolaX X3-PRO-25K-G2 have?

Three, with 2 strings each, for a total of 6 strings. It is the first model in the X3-PRO G2 series to have three trackers: the 8 to 20 kW sizes have two. Each MPPT allows 32 A of operating current and 40 A of short-circuit current.

How many panels can be connected?

The recommended PV power is 37,5 kWp, equal to 150% of the rated power: about 83 modules of 450 Wp distributed over 6 strings, therefore 13-14 modules per string. The operating limit is the current per tracker, not the number of modules: with two strings in parallel on the same MPPT, the sum of the currents must remain within 32 A.

Is an X3-PRO-25K-G2 or two 12 kW inverters more convenient?

A single 25 kW costs less to install, occupies one position, requires only one interface panel and has higher efficiency (98,5% versus 98,2%). Two separate units make sense when the photovoltaic field is physically distant or when redundancy is required, meaning continuing to produce at half power in the event of a fault in one unit.

Can the X3-PRO-25K-G2 limit grid feed-in?

Yes. Export control is integrated and requires an external energy meter at the point of exchange. Any feed-in threshold can be set, down to zero export, a condition that some distributors impose when the available feed-in power is lower than that of the system.

How should it be installed to avoid summer derating?

The inverter operates up to 60 °C but reduces the power delivered above an ambient temperature of 45 °C. On industrial roofs exposed to direct sunlight, a north-facing wall, a ventilated technical room or in any case a shaded position is recommended, keeping the heat dissipation clearances indicated by the manufacturer free. IP66 still allows outdoor installation.