SolaX Wi-BR RS485 Wireless Bridge for Smart Meter
The SolaX Wi-BR is the RS485 wireless bridge that replaces the cable between a SolaX inverter and its smart meter when the meter is far away or on another floor. It works as a pair, AP (inverter side) + STA (meter side), on the 868 MHz band with IEEE 802.11ah: up to 200 m in open space and through 4 floors. DIN rail mounting, 85-277 Vac supply, 2 W max, IP20 for enclosures.
The SolaX Wi-BR (Wireless Bridge) solves one of the most common site problems in systems with storage and export control: the inverter sits in a garage, loft or plant room, while the smart meter has to be close to the grid connection point, often in an outdoor meter box, a basement or on another floor. The link between the two is an RS485 line: the Wi-BR carries it over radio, with no chasing, no trenching and no new conduits. Two DIN rail modules, one next to the inverter and one next to the meter, and inverter-meter communication works just as it does over a cable.
When a wireless inverter-meter link makes sense
A wired RS485 line with shielded twisted-pair cable easily covers hundreds of metres: distance alone is not the reason to choose the Wi-BR. The reason is the cable route. The bridge pays off when laying the cable costs more than the accessory, or simply is not possible:
- Meter in another building or across a yard: no trench and no buried duct
- Apartment blocks: the meter is in the ground-floor meter room and the inverter in the attic, with risers already full
- Renovations and retrofits: finished walls, new floors, no spare conduit
- Listed or protected buildings: every chase in the wall needs approval
- Farms and warehouses: inverter in one building, main switchboard in another
The meter-inverter link is not optional: it tells the hybrid inverter how much the building is importing or exporting, so it can charge and discharge the battery at the right time and apply export limitation or zero export. Without that data the system produces energy but does not regulate it.
How it works: AP + STA pair at 868 MHz
The system consists of two Wi-BR units with different roles: the AP unit connects to the inverter's RS485 port, the STA unit to the meter's RS485 terminals. According to the official SolaX quick installation guide, the two units in the package come factory-paired; to replace or add a STA, press the Reset buttons on AP and STA together for 3 seconds, and the AP keeps searching for one minute.
The radio uses IEEE 802.11ah (also known as Wi-Fi HaLow) in the sub-GHz 863-868 MHz band. Compared with 2.4 GHz Wi-Fi, the lower frequency passes through floors and walls more easily: in the comparison published by SolaX the Wi-BR reaches 200 m and 4 floors, against 100 m and 1 floor for Wi-Fi, 130 m and 3 floors for LoRa, 20 m and 1 floor for Zigbee. The penetration tests used reinforced concrete slabs with 4.5 m floor spacing; with large metal obstacles or strong interference the installation distance should be reduced.
SolaX Wi-BR technical specifications
| Model | SolaX Wi-BR (Wireless Bridge) |
| Operating mode | AP / STA |
| Radio protocol | IEEE 802.11ah |
| Frequency | 863-868 MHz, max EIRP 13.709 dBm |
| Range | Up to 200 m in open space, up to 4 floors (about 30 m vertically) |
| Communication port | 1 x RS485 per unit |
| Power supply | 85-277 Vac (phase voltage) |
| Max power consumption | 2 W |
| Mounting | 35 mm DIN rail |
| Dimensions | 18 x 98 x 66 mm (one DIN module) |
| Ingress protection | IP20, inside an enclosure only |
| Operating temperature | -25 / +55 °C |
| Altitude | Up to 2,000 m |
| Supported meters | Single-phase and three-phase with RS485 output |
| Package contents (SolaX quick guide) | 2 Wi-BR units (AP and STA), 2 antennas with 1 m cable, 1 x 2 m RS485 cable, documentation |
Compatible SolaX inverters and RS485 terminals
The official quick guide lists, for each inverter family, the RS485 port pins to which the AP unit is connected:
| Inverter series | RS485A / RS485B pins |
| X1-Hybrid G4, X1-Hybrid LV, X1-FIT G4, X1-IES, X3-Hybrid G4, X3-FIT G4, X3-IES, X1-Mini G4, X1-Boost G4, X3-ULTRA, X3-MIC G2 | 4 / 5 |
| X1-AC | 7 / 8 |
| X1-SMART G2 | 4 / 5 or 11 / 12, depending on the terminal type |
| X3-PRO G2 | 5 / 6 |
| X3-MEGA G2, X3-FORTH | 7 / 8 |
The bridge is transparent: it does not change the protocol and does not make a meter compatible if the inverter does not support it. Choose the meter among those approved by SolaX for that inverter series, such as the SolaX M1-40 and M3-40 or the SolaX versions of the Chint DDSU666 and DTSU666.
Limits to know before installation
- Mains supply is needed at both ends: each unit is powered at 85-277 Vac, not from the RS485 line. On three-phase systems, neutral plus any one phase is enough
- IP20: the Wi-BR is not waterproof. Install it inside a distribution board or a protective box, never exposed outdoors
- The antenna goes outside the enclosure: SolaX requires it on top of the cabinet. Inside a closed metal enclosure the signal is shielded
- Distance from people: keep the antenna at least 20 cm from people and do not co-locate it with other antennas or transmitters
- It is not an internet dongle: it only replaces the meter-inverter cable. SolaxCloud monitoring still needs the inverter's Pocket WiFi, LAN or 4G dongle
- Weight and warranty are not stated in the official datasheet
Frequently asked questions
How many Wi-BR units are needed to connect one inverter to one meter?
Two: an AP unit on the inverter's RS485 port and a STA unit on the meter. The official SolaX quick guide describes a package with both units already paired, two antennas and an RS485 cable, but some distributors sell single units. Before ordering, check with MR WATT whether you need one or two units.
What is the difference between the Wi-BR and the Pocket WiFi dongle?
They do two different jobs. The Pocket WiFi, LAN or 4G dongle sends inverter data to the internet and the SolaxCloud app. The Wi-BR links the inverter to the meter in place of the RS485 cable, and that is the data the inverter uses to manage the battery and grid export. In a system far from the meter you often need both.
Does the signal pass through reinforced concrete walls and floors?
Yes, within limits. Working at 868 MHz, the Wi-BR penetrates masonry better than Wi-Fi: SolaX states up to 4 floors, measured through reinforced concrete slabs with 4.5 m floor spacing, and up to 200 m in open space. Large metal masses, closed enclosures with the antenna inside and other radio sources reduce the range.
Does the Wi-BR work with a three-phase meter?
Yes. The bridge works with single-phase and three-phase meters with an RS485 output. On a three-phase system the unit is powered from neutral and any one of the three phases. The meter must still be a model supported by the installed SolaX inverter series.
What happens if the radio link drops?
A flashing green RUN LED indicates an RS485 wiring problem; a solid red COMM LED indicates failed pairing, which is repeated by pressing Reset on the AP and then on the STA for 3 seconds. Until the meter data arrives, the inverter cannot control battery charging or export limitation: that is why antenna position and link should be checked at commissioning, with both LEDs solid green.
