Installation · Sofar Solar

Install GridZeno on Sofar KTL.

Sofar's older three-phase KTL inverters from 10 to 70 kW are grid inverters without a battery. The dongle's firmware can't read them yet, so GridZeno shows nothing from them today. Once the firmware can, GridZeno can show the production and, where the protocol allows it, limit export. There's no battery to control. They have two RS485 ports with RJ45 in the wiring box. Sofar has A and B on different pins from the dongle, so the inverter end is crimped with only the two wires that are needed.

Needs an electrician: the inverter has to be opened

The inverter has to be opened to reach the communication port, and behind the cover there are also high-voltage connections. It should be done by a qualified person, such as an authorised electrician.

Applies to: SOFAR 10-20KTL, 30-40KTL, 50-70KTL-G2, 3.3-12KTL-X (G2) and 10000-15000TL-G2
Connection: Network cable with RJ45 plug
Time: About 30 minutes

What GridZeno can do on Sofar KTL today

The older KTL uses Sofar's protocol for 1-40 kW, which writes with a non-standard function code (0x13) and has neither export limit nor battery, only the whole output in per cent. The dongle doesn't read it yet.

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You can connect the dongle by this guide, but it reads nothing from the inverter until its firmware can. GridZeno Dongle for Sofar KTL

What you need

GridZeno Dongle: The device ID is on the label, e.g. GZ-A1B2C3.
Cable: A network cable that's re-crimped at the inverter end with only two wires.
RJ45 plug and crimping tool: For the inverter end, which is crimped after the cable has been passed through the waterproof RJ45 cable gland.
USB power: A 5 V USB charger and a cable with USB-C.

The port

Inside the wiring box behind the bottom cover. The cable goes in through one of the two RS485 cable glands on the underside, marked RS485 IN and RS485 OUT on the 30-40KTL and 50-70KTL. Both ports have the same pins.

Port: RS485 (RJ45 on the communication board)

Sofar's RS485 port, as Sofar numbers the pins. A is on pins 2, 3 and 4 and B on pins 1, 5 and 6. The plug shown with the contacts facing you and the locking tab at the back: pin 1 is furthest to the left.

Pin 2 A, RS485 A
Pin 1 B, RS485 B

The cable

A network cable where the inverter end is crimped with only two wires: the dongle's A on pin 2 and B on pin 1. The other positions in the connector are empty. An ordinary straight cable doesn't work here.

From the dongle to the inverter
Dongle end	Inverter end
Dongle pin 4, blue (A)	Sofar pin 2, RS485 A
Dongle pin 5, white/blue (B)	Sofar pin 1, RS485 B
The other wires	Cut off and insulated

Settings

On the inverter

1.Enter Setting > 9. Set Mod-bus Address (on 3.3-12KTL-X and 10000-15000TL-G2: 8. Set Address): Read the address. It's also shown in the display as A1. The dongle must have the same address.
SWT2 (Match Resistance): Leave it as it is.

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, KTL
Connection: By cable (RS485)
RS485 settings: 9600 baud, 8N1, and the address from the inverter's Set Mod-bus Address.

Step by step

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

1
Read the inverter's Modbus address
Press Back to get to 1.Enter Setting, press OK, and use Up and Down to go to 9. Set Mod-bus Address. On the 3.3-12KTL-X and 10000-15000TL-G2 the item is called 8. Set Address. Note the address: the dongle must have the same one.
2
Turn off the inverter, and open the wiring box
Switch off the AC breaker, and set the DC switch to OFF. Unscrew the bottom cover so you can see the communication board.
3
Pass the cable through the cable gland
Pass the cable through the nut, seal and body of the waterproof RJ45 cable gland and in through one of the RS485 cable glands before the connector is crimped on.
4
Crimp the inverter end with two wires
Crimp an RJ45 connector on with blue (A) on pin 2 and white/blue (B) on pin 1. The other wires are cut off and insulated.
5
Plug the connector into the RS485 port
Push the connector into one of the RS485 ports on the communication board until it clicks. Both ports have the same pins. Put the sealing plug in the body, and tighten the nut.
6
Close the wiring box again
Screw the bottom cover back on so the box is 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 KTL, and the connection By cable (RS485). If the inverter's address isn't 1, set the same address under Settings, Modbus. 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

The wiring box behind the bottom cover also has the AC and DC connections. Turn off the inverter at the AC breaker and the DC switch before the cover is opened, or let the installer do it.

Use one of the two RS485 ports. The WIFI port is for Sofar's own Wi-Fi module, and the terminal CNT10 is a relay. An ordinary network cable must not be used, because the dongle's GND on pin 3 would hit Sofar's A on pin 3.

On the 3.3-12KTL-X and 10000-15000TL-G2, DRM and remote stop are on a separate terminal block, where pin 8 gives 5 V out. The dongle must not go in it.

The manual for the 30-40KTL also mentions a rotary switch, SWT4, for the address. Use the address the inverter shows in the display as A1.

Sofar KTL isn't on the compatibility list yet. If you're stuck, write to us with the model name.

Source

Ports, pins and menus are from the manufacturer's own manual: SOFAR 10K-20KTL User manual (EN, 2018-03-19), Sofar 30~40KTL User manual (EN, version 1.0, 2015-08-06) Sofar 50~70KTL User manual (EN, 2018-03-07), SOFAR 50-70KTL-G2 (ES, 2018), SOFAR 3.3-12KTLX-G2 (EN, 2020) and SOFAR 10-15KTL-G2 (EN, 2019), Section 4.4, Connecting Communications Cables (Figure 4-10/4-11, RS485 Connecting Communications Cables), Communications Port Description (SWT2), and 6.3, Main Interface (9. Set Mod-bus Address).