Installation · Sofar Solar

Install GridZeno on Sofar KTLX 25-136 kW.

Sofar's large three-phase grid inverters for business and farming have the same 16-pin COM connector as KTLX-G3, either as a square block or a round connector. GridZeno can show the production and, where the protocol allows it, limit export. The dongle is connected with three wires: A in pin 1, B in pin 3 and GND in pin 7.

Applies to: 25-50KTLX-G3, 60-80KTLX-G3, 100-125KTLX-G4, 100-136KTL-PRO and 75-136KTL-HV
Connection: Wires in the inverter's terminal plug
Time: About 30 minutes

A grid inverter without a battery. GridZeno shows solar, consumption and grid and lowers the inverter's export limit at negative prices. What GridZeno can do on Sofar KTLX 25-136 kW

How the dongle recognises it: The serial number in holding 0x0445 with the code S3 (25-50KTLX-G3), S4 (60-80KTLX-G3) or Q1 (75-136KTL). A 20-character serial number with the code 036 is 100-125KTLX-G4.

GridZeno Dongle for Sofar KTLX 25-136 kW

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.
Wire strippers and ferrules: Three wire ferrules for the three wires in the COM connector.
USB power: A 5 V USB charger and a cable with USB-C.

The port

On the underside of the inverter, by the USB port. On 100-125KTLX-G4 the port is called COM1. The same connector is used for energy meter and DRM, so there may already be wires in it.

Port: COM (16-pin connector, RS485 Modbus/DRMs)

The COM connector, as Sofar numbers the pins. Pins 1 and 2 are A, pins 3 and 4 are B, and pin 7 is GND.S. The pins are the same on the square and the round version. The numbers are on the plug.

Pin 1 A, RS485 A
Pin 3 B, RS485 B
Pin 7 GND, GND.S
Pin 8 Must not be connected, DRM0

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, only the three wires from pins 4, 5 and 3 are used, with terminals on.

From the dongle to the inverter
Dongle end	Inverter end
Dongle pin 4, blue (A)	COM pin 1, RS485 A
Dongle pin 5, white/blue (B)	COM pin 3, RS485 B
Dongle pin 3, white/green (GND)	COM pin 7, GND.S
The other wires	Cut off and insulated

Settings

On the inverter

Enter Setting > 7. Set Address: 01, as from the factory. The password is 0001. On 25-50KTLX-G3 and 100-125KTLX-G4 the address is set on the display or in the SofarCloud app under 485 Parameter.

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: Sofar Solar, KTLX
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 the address
On the display, go to Enter Setting and 7. Set Address, and enter the password 0001. The address must be 01, as from the factory. On 25-50KTLX-G3 it can also be set in the SofarCloud app under System Setting and 485 Parameter.
2
Unplug the COM connector
Switch off the inverter first: switch off the AC breaker, set the DC switch to OFF, and wait 5 minutes. Take the COM connector out of the port on the underside.
3
Pass the cable through the connector's parts
Pass the cut end of the cable through the connector's nut and seal before the wires are put in.
4
Prepare the cable
Strip the outer sheath and the three wires from pin 4 (blue), pin 5 (white/blue) and pin 3 (white/green), and put terminals on: on the square connector 20 to 25 mm of sheath and 12 to 15 mm of wire, on the round one 20 to 40 mm of sheath and 7 mm of wire. Insulate the other wires.
5
Put the wires in pins 1, 3 and 7
Blue (A) goes in pin 1, white/blue (B) in pin 3 and white/green (GND) in pin 7, following the numbers on the connector. Pins 2 and 4 are for a possible next inverter in the chain.
6
Plug the connector back in
Screw the connector together, and plug it into the COM port so it's sealed.
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, Sofar Solar KTLX, 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 5 and 6 are the energy meter's connection and pins 8 to 12 the DRM control, where pin 8 can stop the inverter. Don't touch them.

On 100-125KTLX-G4, pins 13 to 16 are an extra RS485 port. Sofar writes that you must choose one of them. If there's already a data logger on pins 1 to 4, write to us before you connect the dongle.

If there are several daisy-chained inverters on pins 1 to 4, each must have its own address from 1 to 31.

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.

What GridZeno can control on Sofar KTLX 25-136 kW, and how, is on the page about Sofar KTLX 25-136 kW. If you're stuck, write to us with the model name.

Source

Ports, pins and menus are from the manufacturer's own manual: SOFAR 25-50KTLX-G3, 60-80KTLX-G3, 100-125KTLX-G4, 100-136KTL-PRO and 75-136KTL-HV User Manuals (EN), The pin table for the COM connector (RS485 Modbus/DRMs) and Enter Setting, 7. Set Address.