SolaX X3-FTH-125K125kW three-phase C&I string inverter, 12 MPPT

Overview

The X3-FTH-125K is the most powerful X3-FORTH model in the 220/380V to 277/480V range: 125kVA rated and 132kVA maximum output, 181.2A at 230/400V. Twelve MPP trackers take two 32A strings each, and SolaX recommends up to 188kWp of PV. Maximum efficiency is 98.6%. The 87kg IP66 unit supports built-in export control, night-time reactive power compensation and parallel operation via Modbus or DataHub.

• 75–125kW, 9 or 12 MPPT, two strings each
• 32A per tracker, 180–1000V MPPT range
• 98.6% maximum, 98.3% European efficiency
• Copper or aluminium AC cable up to 240mm²
• Type II SPD on DC and AC, optional AFCI
• IP66, smart fan cooling, CEI 0-16 certificate

How it works

The X3-FORTH converts the output of large PV arrays into three-phase AC for 220/380V, 230/400V or 277/480V grids, with or without neutral. The 75kW to 110kW models have nine MPP trackers, with twelve available as an option on the 100kW and 110kW, while the 120kW and 125kW have twelve. Each tracker accepts two strings at up to 32A and 46A short-circuit current.

Built-in export power control limits feed-in through a meter. Up to ten inverters can be linked over Modbus in a master-slave daisy chain, or up to sixty under a SolaX DataHub that also enforces zero injection. Night-time reactive power compensation, AC terminal temperature detection, string current monitoring, I-V curve diagnosis and 24-hour operation monitoring are part of the design.

Key features

Maximum efficiency is 98.6% and European efficiency 98.3%. The MPPT range is 180–1000V, with 1100V maximum input and a 200V start-up voltage. SolaX recommends up to 120kWp of PV on the 75kW and 80kW models and up to 188kWp on the 125kW model. Type II SPD protects the DC and AC sides, with Type I+II as an option; AFCI is optional, the AC auxiliary power supply is built in and anti-PID needs an external device.

Installation and compatibility

The 985×660×327.5mm housing weighs 83kg up to 110kW and 87kg for the 120kW and 125kW, so it is lifted by four installers or a crane rated for at least 180kg and hung on the supplied bracket on a wall or stand. Several inverters need at least 30cm at the sides and 60cm above and below each unit. The IP66 enclosure operates from -25°C to +60°C at up to 4000m.

AC connection uses five-core copper cable of 70–240mm² or aluminium of 95–240mm², with OT terminals bought separately, and PV strings use 4–6mm² copper cable rated 1500V. Listed standards include IEC/EN 62109-1/-2, EN 50549, VDE 4105, VDE 4110, IEC 61727, IEC 62116 and AS 4777.2, and SolaX publishes a CEI 0-16 certificate for the X3-FTH-75K to 125K.

Monitoring and settings

Monitoring, remote settings and firmware upgrades run on SolaXCloud through a SolaX Pocket WiFi, LAN or 4G dongle. RS485, USB and DRM interfaces are standard. Models with the (L) suffix have a 16×2 LCD, the others four LED indicators, and night-time consumption is below 10W. For large plants the DataHub collects data from all inverters and handles centralised control.

Questions and answers