Installation · SolaX

Install GridZeno on SolaX X3-MEGA G2, X3-FORTH, FORTH G3, X3-GRAND HV.

X3-MEGA, X3-FORTH, FORTH G3 and X3-GRAND are SolaX's large three-phase grid inverters for business and farming, without a battery. GridZeno can show the production and, where the protocol allows it, limit export. The dongle is connected with wires in the 30-pin COM connector: pins 1 and 2, which SolaX calls RS485-1 IN, and GND on pin 3.

Applies to: X3-MGA-20K to 60K-G2, X3-FTH-40K to 150K, FTH80T to 125T and X3-GRD-300K to 350K-HV
Connection: Wires in the inverter's terminal plug
Time: About 30 minutes

Large grid inverters without a battery. GridZeno shows the solar production on an X3-MEGA G2 and X3-FORTH but can't control anything on them. What GridZeno can do on SolaX X3-MEGA G2, X3-FORTH, FORTH G3, X3-GRAND HV

How the dongle recognises it: The serial number is in input 0x32, not in holding 0x00: X3G04, X3G05, X3G06, X3G075, X3G08, X3G01, A3F10 or MAXMEG_G2. The X3-FORTH G3 and X3-GRAND HV have no public register map and aren't recognised yet.

GridZeno Dongle for SolaX X3-MEGA G2, X3-FORTH, FORTH G3, X3-GRAND HV

What you need

GridZeno Dongle: The device ID is on the label, e.g. GZ-A1B2C3.
Cable: GridZeno's Modbus cable with one end cut off, or another network cable with one plug.
Ferrules and crimping tool: Wire ferrules for 0.5 to 0.75 mm² wire, e.g. ENY0512 or ENY7512.
USB power: A 5 V USB charger and a cable with USB-C.

The port

The round, waterproof COM connector on the underside of the inverter, by the Dongle port. The same connector is used for energy meter and DRM, so there may already be wires in it.

Port: COM (30-pin connector)

The COM connector, as SolaX numbers the pins. Pins 1 to 3 are RS485-1 in, 4 to 6 onwards to the next inverter, and 7 and 8 the energy meter. The numbers are on the plug.

Pin 1 A, RS485A IN+
Pin 2 B, RS485B IN-
Pin 3 GND, IN-GND (reserved on X3-FORTH)
Pin 9 Must not be connected, +5V

The cable

A network cable where one end has an RJ45 plug for the dongle and the other end is cut off. At the inverter end, the wires from pins 4 and 5 are used, and from pin 3 for GND, with terminals (wire ferrules) on. On X3-FORTH pin 3 is reserved: only the two wires from pins 4 and 5 are used.

From the dongle to the inverter
Dongle end	Inverter end
Dongle pin 4, blue (A)	COM pin 1, RS485A IN+
Dongle pin 5, white/blue (B)	COM pin 2, RS485B IN-
Dongle pin 3, white/green (GND)	COM pin 3, IN-GND. Not on X3-FORTH
The other wires	Cut off and insulated

Settings

On the inverter

Settings > Communication > RS485 Addr and RS485 Baud: Address 1 and 9600 baud, as from the factory. On FORTH G3 without a display (-3) they're set in the SolaXCloud app.

In GridZeno's Welcome

The inverter is chosen in GridZeno: in Welcome the first time, and later under System, Change inverter. The dongle fetches its setup from there.

Manufacturer and model: SolaX, X3-MEGA / X3-FORTH
Connection: By cable (RS485)
RS485 settings: Keep the default: 9600 baud, 8N1, address 1.

Step by step

Each step has a small drawing that shows what to do.

1
Check address and baud rate
On the display, go to Settings and Communication. RS485 Addr must be set to 1 and RS485 Baud to 9600, as from the factory. On FORTH G3 without a display, the same settings are in the SolaXCloud app.
2
Unplug the COM connector
Switch off the inverter first: switch it off on the display or from the monitoring, switch off the AC breaker, and set the DC switches to OFF. Wait the time the label says: 5 minutes on X3-MEGA and X3-FORTH, 15 on FORTH G3 and 45 on X3-GRAND. Press the latch in, and pull out the COM connector.
3
Pass the cable through the connector's parts
Take the connector apart, and remove the blanking plug only from the hole you're going to use. Pass the cut end of the cable through the nut, the seal and the connector housing, in that order.
4
Prepare the cable
Strip 12 to 14 mm of the wires from pin 4 (blue) and pin 5 (white/blue) and, except on X3-FORTH, pin 3 (white/green). Crimp terminals on. Insulate the other wires.
5
Put the wires in pins 1, 2 and 3
Blue (A) goes in pin 1, white/blue (B) in pin 2 and white/green (GND) in pin 3, following the numbers on the connector. On X3-FORTH pin 3 is reserved, so the white/green wire isn't used. Push them in until they click. Don't touch wires already in the other pins.
6
Put the COM connector back in
Assemble the connector until it clicks, and tighten the nut. Plug the connector into COM with the arrows lined up, until it clicks.
7
Plug the RJ45 end into the dongle
The cable's other end goes into the dongle's RS485 port. Place the dongle somewhere dry and close to the inverter, so the cable doesn't hang from the plug.
8
Connect power to the dongle
Plug the USB-C cable into the dongle and the charger into a socket. The dongle starts by itself. It gets power from the charger, not from the inverter.
9
Connect the dongle to the network
Over Wi-Fi: the first time, the dongle creates its own Wi-Fi, GridZeno-Setup- followed by the last characters of the device ID. Connect your phone to it, choose your own network, enter the password, and press Save and connect. When it says Connection OK, press Go to GridZeno. Over cable (LAN): plug a network cable from the router into the dongle's network port.
10
Log in, and choose your inverter
Log in to GridZeno. Welcome pairs the dongle with its device ID. Then choose your inverter, SolaX X3-MEGA / X3-FORTH, and the connection By cable (RS485). Press Save inverter, and the dongle fetches its setup and reads the inverter.

The dongle's own setup is described with screenshots in The user guide, and the pairing in Getting started.

Take care

Pins 4 to 6 pass the RS485 connection on to the next inverter, and pins 7 and 8 are the energy meter's. The dongle goes in pins 1 to 3. If the inverters are already daisy-chained, write to us before you connect the dongle.

Pin 9 carries 5 V. Never connect anything from the dongle to it.

The inverters are large and heavy and are part of high-voltage systems. The work should be done by a qualified person, e.g. an authorised installer.

If you aren't used to fitting wires in a terminal connector, let the installer do it.

What GridZeno can control on SolaX X3-MEGA G2, X3-FORTH, FORTH G3, X3-GRAND HV, and how, is on the page about SolaX X3-MEGA G2, X3-FORTH, FORTH G3, X3-GRAND HV. If you're stuck, write to us with the model name.

Source

Ports, pins and menus are from the manufacturer's own manual: SolaX X3-MEGA G2, X3-FORTH, FORTH G3 and X3-GRAND HV User Manuals (EN), The pin table for the 30-pin COM connector (RS485-1 on pins 1 to 3) and Settings, Communication, RS485 Addr and RS485 Baud.