X3-EPS BOX
The SolaX X3-EPS Box enables the EPS (Emergency Power Supply) function in the SolaX X3-Hybrid G4 three-phase hybrid inverters. It automatically switches to emergency power from photovoltaic and batteries in ≤ 0.5 seconds, with a maximum current of 3 × 63 A and load power up to 15 kW. Integrated dual Eaton contactor, protection rating IP65.
The SolaX X3-EPS Box is the essential accessory to enable the backup function in SolaX X3-Hybrid G4 three-phase hybrid inverters. Thanks to its two integrated power contactors, the box automatically manages the switching between the public grid and EPS (Emergency Power Supply) mode, ensuring electrical continuity for priority loads in the event of a blackout, powered by photovoltaic panels and high-voltage batteries.
How does the SolaX X3-EPS Box work?
The X3-EPS Box integrates two pre-wired power contactors that manage "power steering" between the grid supply and emergency loads. Upon detecting a grid interruption, the box isolates the EPS circuit from the public grid in about 0.5 seconds and powers it with energy produced by the photovoltaic system and stored in the batteries. When the grid returns, it safely closes the contactor, reconnecting the system to the three-phase grid.
X3-EPS Box Technical Specifications
| Compatibility | SolaX X3-Hybrid G4 three-phase hybrid inverters (E version) |
| Grid type | Three-phase (3/N/PE ~ 400/380 V) |
| Max EPS input current | 3 × 63 A |
| Max output current (on-grid) | 3 × 63 A |
| Max output current (EPS) | 3 × 63 A |
| Max controllable load power | 15 kW |
| Internal contactor | Eaton DILM 40C (220-230 V, 50 Hz) |
| EPS switching time | ≤ 0.5 s |
| Electrical life of contactors | 1.2 × 10⁶ cycles |
| Operating temperature | -20 °C ÷ +60 °C |
| Nominal frequency | 50/60 Hz |
| Application | Residential, commercial, small industrial |
When is the X3-EPS Box necessary?
The EPS function is integrated into the X3-Hybrid G4 inverter, but to make it operational on a dedicated three-phase circuit, it is necessary to install the X3-EPS Box (or alternatively the X3-Matebox Advanced). Without this accessory, the EPS output of the inverter is not connected to the electrical panel and the backup function is not active. The EPS Box is the most direct solution for residential and commercial three-phase systems that already have the wiring between inverter and batteries completed.
What is included in the supply?
- X3-EPS switching box with integrated double Eaton contactor
- SolaX installation instructions
Not included: connection cables, residual current circuit breakers, electrical installation materials.
Frequently Asked Questions
Is the SolaX X3-EPS Box compatible with all X3-Hybrid inverters?
The X3-EPS Box is designed for SolaX X3-Hybrid G4 three-phase hybrid inverters, specifically the E version with dedicated EPS output. It is not compatible with single-phase X1-Hybrid inverters (for which the X1-EPS Box is required) nor with inverters from other brands. Always check the exact model of the inverter before purchasing.
What is the maximum power that can be managed by the X3-EPS Box in backup mode?
The X3-EPS Box supports a maximum output current of 3 × 63 A in EPS mode, with a maximum controllable load power of 15 kW. The actual available power depends on the size of the X3-Hybrid inverter and the remaining charge in the batteries. In the absence of batteries, the Super-Backup function (if enabled) limits the EPS power to 50% of the inverter's nominal power.
Can I use the X3-EPS Box without a storage battery?
Yes, thanks to the Super-Backup function available on the X3-Hybrid G4 (firmware ARM ≥ 1.44, DSP ≥ 1.47). In this mode, the EPS loads are powered exclusively by the photovoltaic system, with power limited to 50% of the nominal value. The function is disabled by default and must be activated from the inverter menu: Main → Settings → Advanced Settings → EPS Settings → Super-Backup.
What is the difference between the X3-EPS Box and the X3-Matebox?
The X3-EPS Box exclusively manages EPS switching and is the ideal solution for systems where inverter-battery wiring is already completed. The X3-Matebox (Basic or Advanced) is an integrated panel that also manages the wiring between inverter and batteries and, in the Advanced version, enables backup for the entire load (whole-home backup). The Matebox is preferable for new installations, the EPS Box for retrofits on existing systems.
Does installing the X3-EPS Box require a qualified electrician?
Yes. Connecting the X3-EPS Box to the three-phase panel requires a qualified electrical installer in accordance with CEI 64-8 standards and preferably a certified SolaX installer. The intervention involves modifying the three-phase distribution circuit, verifying the selectivity of protections, and complying with electrical safety standards. Non-compliant installation voids the inverter warranty.
