SolaX X3-MIC G2 three-phase inverter: models and specifications

A three-phase supply is common in larger UK homes, in converted properties and anywhere with a big electrical load, and it changes what a solar inverter has to do. The SolaX X3-MIC G2 is built for exactly that job: the maker describes it as a three-phase residential on-grid inverter, sold in eight sizes from 3kW to 15kW¹. It is a string inverter, so the panels are wired into one or more strings and the inverter converts the whole array's DC output to mains AC.

The headline numbers are a maximum efficiency of 98.3% and a European efficiency of 97.8%¹. It accepts 200% DC oversizing, meaning the array can be roughly twice the inverter's rated output, and 32A of input current per MPP tracker³. The maximum PV input voltage is 1000 V, and night-time consumption is under 3W¹.

What it does not do is store energy. There is no battery connection on this model, so a household wanting to keep surplus generation for the evening needs a separate battery inverter or an AC-coupled battery alongside it. That is the central trade-off of the range: a straightforward, efficient grid-tied inverter, with storage handled elsewhere.

What the X3-MIC G2 is, and who it suits

The X3-MIC G2 is a three-phase string inverter for residential systems, and the maker's own summary places it in a power range of 3kW to 15kW⁶. It sits in the on-grid half of the SolaX catalogue rather than the hybrid half: the datasheet calls it a "Three-phase Residential On-grid Inverter"¹. That single word, on-grid, defines what the household gets and what it does not.

For a home with a three-phase supply, the case for a three-phase inverter is straightforward. A single-phase inverter on a three-phase supply can only use one phase, which limits how much can be exported and how the load is balanced across the property. A three-phase unit spreads generation across all three phases, which suits larger arrays and heavier household loads. The X3-MIC G2's rated AC voltage is given as 3 / N / PE, 220 / 380 V and 3 / N / PE, 230 / 400 V, so it is designed for the standard European three-phase arrangement¹.

It is not the only shape SolaX sells. The MIC G3 is described as a compact three-phase residential on-grid inverter, and the X3-PRO G2 runs from 8kW up to 30kW for larger properties⁷. The X3-MIC G2 sits between the small end and the commercial end, which is where most three-phase homes land.

The dependence it leaves in place is the grid itself. An on-grid string inverter needs a live grid connection to operate, so it cannot run the house in a power cut. A household wanting backup power needs a hybrid or off-grid design, which is a different product decision covered in hybrid inverters and string inverter vs hybrid inverter.

The range: eight models from 3kW to 15kW

The X3-MIC G2 comes in eight rated outputs: 3.0kW, 4.0kW, 5.0kW, 6.0kW, 8.0kW, 10.0kW, 12.0kW and 15.0kW¹. The maker's guidance describes the same span as covering a versatile power range from 3kW to 15kW for three-phase residential systems³. The product page lists the sizes in the same order, so the two agree².

The rated output power figures are given per model: 3000 W for the X3-MIC-3K-G2, 4000 W for the 4K, 10000 W for the 10K and 12000 W for the 12K¹. Those are the continuous AC outputs the inverter is rated to deliver, and they are the numbers an installer matches against the household's demand and the array size.

Choosing between them is a matter of matching the inverter to the array and the property's consumption, not simply picking the largest. A 3kW model on a small three-phase flat and a 15kW model on a large house with a heat pump are both sensible uses of the same family. The wider question of sizing is covered in what size solar system does a home need and what size inverter do I need.

Efficiency: 98.3% peak, 97.8% European

The datasheet gives the X3-MIC G2 a maximum efficiency of 98.3% and a European efficiency of 97.8%¹. The maker's guidance rounds this to an "impressive 98% efficiency rating"³, and the product page states up to 98.5% efficiency². The documents differ slightly on the headline figure, and the datasheet values are the ones tied to the specific appliance.

The gap between the two efficiency figures is worth understanding, because it is the difference between a laboratory best and a realistic average. Peak efficiency is measured at one optimal operating point. European efficiency is a weighted figure across several load levels, which is closer to how an inverter behaves across a real day of changing sunlight. The 97.8% European figure is therefore the more useful number for estimating annual yield.

For context within the SolaX range, the X3-IES-A is listed at 98.6% peak efficiency and the X3-PRO G2 at up to 98.5%⁹. The X3-MIC G2's 98.3% sits just below those, which is a normal spread across product families rather than a meaningful performance gap. What matters more in practice is string design, shading and how well the array is matched to the inverter.

Efficiency also has a direct bearing on independence. Every percentage point lost in conversion is generation the household cannot use or export, so a high-efficiency inverter makes the most of a given roof. It does not, however, change the fundamental dependence: the system still needs the grid to operate, and the household still buys whatever it does not generate.

DC input and PV array sizing: 200% oversizing, 1000V, 32A per MPPT

The DC side is where the X3-MIC G2 is most flexible. The maximum PV input voltage is 1000 V, and the maker's guidance gives an input capacity of 32A per MPP tracker¹. The inverter supports 200% DC oversizing, which means the array's rated output can be up to twice the inverter's AC rating³. SolaX describes this across its residential string inverter range as allowing more PV modules to be connected¹⁰.

Oversizing is a design choice with a clear logic. Panels rarely produce their rated output in UK conditions, so an array larger than the inverter can still be worthwhile: the inverter clips the rare peaks and runs closer to its capacity for more of the year. The maker's recommended array sizes show the headroom in practice: 6 kWp on the 3K model, 8 kWp on the 4K, 12 kWp on the 6K, 24 kWp on the 12K and 30 kWp on the 15K¹.

The 32A per tracker figure matters when strings are planned. It sets how many panels can be wired onto one input, and it is generous enough for modern high-output modules. The number of MPP trackers varies by model in the range, so the datasheet for the exact size should be checked before strings are designed. More trackers let arrays on different roof aspects work independently, which reduces the effect of shading and orientation.

AC output and grid connection: voltages, power factor and THDi

On the AC side the X3-MIC G2 is rated for 3 / N / PE, 220 / 380 V and 3 / N / PE, 230 / 400 V output, which covers the standard three-phase supplies found in UK homes¹. The start-up voltage is 150 V, the point at which the inverter begins working as the array wakes up¹. Total harmonic distortion at rated power is under 3%, the measure of how cleanly the inverter's output matches the grid waveform¹.

That distortion figure is the one that matters for grid connection. A high THDi means the inverter is pushing a distorted current onto the network, which is what the connection standards exist to prevent. Under 3% at rated power is a low figure and sits comfortably within what a distribution network operator expects. The practical consequence for a household is that the inverter is unlikely to be the reason a connection application runs into trouble.

Connecting any solar system to the grid in the UK involves an application to the local network operator, and the process differs by size. The rules are set out in connecting solar to the grid: G98 and G99 explained, and where an export limit is imposed, export limitation and G100 for home solar covers how that is enforced. The X3-MIC G2 has built-in export power control, which is the mechanism an installer uses to comply with a limit².

The dependence here is structural rather than optional. A grid-tied inverter synchronises with the mains and stops when the mains fails, which is a safety requirement as much as a design choice. The household gets the grid as a free battery of sorts, absorbing exports and supplying shortfalls, but it also inherits the grid's terms, its connection process and its outages.

Monitoring, smart loads and export control

The X3-MIC G2 has built-in export power control, and the product page also lists smart loads management for devices such as a heat pump or a smart EV charger². That combination is what turns a plain inverter into something that can be steered: export control keeps the system within a network limit, while smart load management can direct surplus generation to a device that would otherwise draw from the grid.

Monitoring is the other half. SolaX's wider range uses cloud-connected monitoring, and the maker's warranty terms tie a free warranty upgrade to an inverter being connected to the SolaX cloud with generation data uploaded⁴. That link between monitoring and warranty is worth noting: the same connection that gives the household visibility of its generation is also the condition for the longer cover.

The dependence this creates is easy to overlook. Local generation continues without an internet connection, but remote monitoring, historical data and any app-based control depend on a home broadband connection and the manufacturer's servers. A household that values independence should treat the monitoring platform as a convenience layer rather than a critical part of the system. The wider subject is covered in monitoring a solar PV system.

Protection, certifications and IP66 build

The X3-MIC G2 carries an IP66 ingress protection rating, which means it is sealed against dust and against water projected from any direction¹. That rating is what allows the inverter to be mounted outdoors or in an outbuilding rather than only in a garage or plant room. The same IP66 rating appears across much of the SolaX range, including the MIC G3, the X3-PRO G2 and the X3-IES-A⁷.

Arc fault protection is available as an option rather than as standard: the product page lists AFCI support as optional². Arc fault detection is a safety feature that identifies the electrical signature of a failing DC connection, and it is more commonly required in some markets than others. A household that wants it should confirm at the design stage that the specified model includes it, because it is not fitted by default.

The wider safety picture for a PV installation, including DC isolation and surge protection, is covered in solar PV safety: fire risk, DC isolation and surge protection. For the X3-MIC G2 specifically, the sealed enclosure and the low harmonic distortion are the two build features that bear most directly on a safe, straightforward grid connection.

Warranty: 7 years standard, and how to reach 10

The X3-MIC G2 sits in the group of SolaX inverters carrying a 7 year standard warranty, alongside the X1-MINI, X1-Boost, X3-PRO and others⁴. The maker's warranty terms state that the period starts from the earlier of two dates: the date the product was first installed, or six months after the date of production⁴. That second date is the one to watch, because a unit that sits in a warehouse or a van for months before installation starts its clock earlier than the household might expect.

There is a free upgrade path. Where an inverter is connected to the SolaX cloud and generation data has been successfully uploaded to SolaX's servers, the warranty is freely upgraded to 10 years standard⁴. The same condition appears in the maker's guidance on inverter lifespan, which describes a free upgrade to 10 years if connected to SolaX Cloud and generating data¹¹. The upgrade is therefore tied to the monitoring connection described above, not to a payment.

Registration is the step that makes any of this enforceable. The maker's guidance is to register within 90 days of commissioning, after which the warranty certificate and exact expiry date are stored in the online account¹². If that window is missed, the warranty automatically starts six months after the product left the factory¹². Registration problems are handled by the SolaX service team by email⁵.

The dependence this creates is a continuing one. The longest cover depends on the inverter staying connected to the maker's cloud and uploading data, which means a working broadband connection and a manufacturer's platform remaining available for the life of the system. A household that lets the connection lapse may find the warranty reverts to the standard term. The general subject is covered in solar panel warranties, degradation and lifespan.

Where the X3-MIC G2 has limits

The clearest limit is the absence of battery support. The X3-MIC G2 is an on-grid inverter, and the maker's battery-capable products are a separate family: the X3-Hybrid G4 is described as a three-phase residential hybrid inverter with built-in battery readiness, and the X3-HYB-G4 PRO offers dual battery ports¹³. A household that wants to store surplus generation needs one of those, or an AC-coupled battery system working alongside the X3-MIC G2.

The second limit is the grid dependence itself. An on-grid inverter cannot run the home during a power cut, because it must shut down when the mains fails. Backup power is a feature of hybrid and off-grid designs, covered in do solar panels work in a power cut and off-grid solar for homes, cabins and boats. For a household whose priority is resilience rather than bill reduction, the X3-MIC G2 is the wrong starting point.

The third is availability and pricing. SolaX equipment reaches UK homes through installers rather than direct retail, and independent guidance describes the brand's battery systems as available via UK installers¹⁵. There is no published manufacturer list price for the X3-MIC G2, so costs come as installer quotes after a survey. Availability of individual models can also vary by region, a pattern the maker notes on other products in its range¹⁵.

The brands and ranges sold alongside it

SolaX sells a broad catalogue in the UK, and the X3-MIC G2 is one entry in it. The three-phase hybrid side includes the X3-Hybrid G4, a three-phase residential hybrid inverter with battery readiness, and the X3-HYB-G4 PRO, which offers dual battery ports for design flexibility¹³. The X3-NEO-LV is a low-voltage three-phase hybrid option listed from 5kW to 20kW, with up to 200% PV oversizing and 110% AC output¹⁶.

For larger properties, the X3-PRO G2 runs from 8kW to 30kW and includes smart loads management for a heat pump or smart EV charger⁸. The X3-IES-A is a three-phase hybrid with 98.6% peak efficiency, intelligent load management and AI-ready energy management that forecasts solar generation and home consumption⁹. The MIC G3 is the compact three-phase on-grid sibling of the X3-MIC G2⁷.

On the single-phase side, the X1-Hybrid G4 and the X1-IES cover smaller homes, and the X1-Micro range covers module-level conversion¹⁷. The X3-ULTRA serves the commercial end at 15kW to 30kW¹⁹. For a household comparing brands rather than models, SolaX vs Growatt and GoodWe vs SolaX set out the alternatives, and SolaX hybrid inverters for home solar covers the wider range.