Clivet/Midea Heat Pump integration - ESPHome/Modbus/Dongle

Hardware
21

Hi all,
This is something that I’ve been looking for for ages. I have a Midea heat pump and it has zero connectivity at the moment, I just have the awful control panel. Does anyone know where I could find a diagram demonstrating how to wire this up? I’ve never so much as looked inside the heat pump, but being able to get this level of control would allow me to automate all sorts. I’m hoping it would allow me to tailor my own weather compensation etc.

Thanks,

Tom

22

Hi Tom,

As I mentioned above. Get Sven’s unit and you’re good to go :blush: it includes instructions.

Good luck

23

I ordered the controller from Sven… can’t wait to receive it. I’ll keep you posted. Thanks!!!

1 Like
24

I uploaded the manual for AQUA Clivet Swan 2.
All modbus address can be found at page 86.

Download

25

Hello guys, I recently installed a SWAN2. Could you explain how to connect it? I have seen the product I need to buy, but I am not sure where to connect it. Is there also a WiFi version? Because I would have trouble running the cable all the way to the pump. Could someone kindly give me some guidance? Thanks.

26

You need that rs485 to ethernet module LINK to converte modbus rs485 to ethernet, then you can make a wifi link from ethernet module over wifi to switch over tcp.

27

Thanks for your reply. My only doubt is where the electronic board for the Modbus connection is located. I have seen the wiring diagram in the manual, and it doesn’t seem complicated to connect the cable to the connector, but my doubt is where it is located and what I need to disassemble to make the connection.

28

hey giuliano, it’s inside the SWAN, you have to open the top and then open the metal cover with the holes and connect it there. It’s pretty easy.

1 Like
29

searching for solutions i came across this thread like a hundred times - and as I’m still searching, I’ll try my lucj right here.

given I have a different appliance, but same or at least similar issue.

Midea clone / Mundoclima Heatpump with a 2 wire wired indoor panel, manual states:

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which makes me assume I can wire the modbus to TCP converter (waveshare as above, but wifi) directly to the three clamps of the indorr unit.
on the other hand I see A and B clamps directly on the outdppr units board, which are not mentioned at any other point - do i need to wire directly to these ports?

30

Yes you wire them on the internal module. There’s not really anything that can go wrong, wire it up and check if you can get a mod bus connection. You can use some mod bus read tool to read the registers and see if it works.

31

that’s what i tried so far - can’t establish a connection
or i don’t see it, the interface of the adapter is… let’s say not optimal…

32

doesn’t the adapter indicate the connection? My waveshare does

33

no matter what i wire to, H1 and H2 inside or outside, the waveshare doesn’t receive anything. or I’m already messing that up…

34

I asked Chatgpt for you:

1. Identify the AC’s Modbus pinout

Most HVAC units that speak Modbus RTU over RS-485 have three terminals labelled something like:

  • A (sometimes labelled D+ or “+”)
  • B (sometimes labelled D– or “–”)
  • E (earth/ground or shield connection)

A ↔ D+: the non-inverting RS-485 data line
B ↔ D–: the inverting RS-485 data line
E ↔ GND/Shield: chassis ground/shield (optional but recommended)

2. Wire it up

  1. Shut down both the AC unit and the gateway before wiring.
  2. On the AC side, loosen the terminals A, B and E.
  3. On the WavesHere gateway, locate its RS-485 screw-terminal block (often labelled A, B and G or A, B, ⏚).
  4. Use a twisted-pair cable for A/B:
  • AC A → Gateway A (D+)
  • AC B → Gateway B (D–)
  1. Connect the shield or ground:
  • AC E → Gateway G/⏚ (earth/shield)
  1. Tighten screws firmly (but don’t over-torque).

Note: If your cable has an overall shield, bond one end only (typically at the gateway) to minimize ground-loop noise.

35

thanks Tom, but unfortunately that was the first varait I tried.

in the meantime I received a reply from Mundoclima

La conexión a modbus se realiza como se indica en el manual, conexiones “A, B+ y E” en el controlador.

Connection to modbus is done via the indoor unit on terminals A,B and E.

At least I now kow this side only have to figure out the waveshare.

36

Hi everyone,

I own a Clivet Sphera EVO 2.0 8.1 kW (MISAN-YEE 1S 2.1 + SQKN-YEE 1 TC), which is a Midea clone.

I’m trying to integrate the unit with my home automation supervisor via Modbus, but so far without success.

Wiring setup:

Internal RS485 terminals H2(+) and H1(–) on the heat pump → USR-W610 converter (A↔H2, B↔H1), 5 m shielded cable (shield grounded on the master side).

Serial settings on the HP as per manual: 9600 baud, 8 data bits, no parity, 1 stop bit; “HMI address from BMS” = 2.

USR-W610 configured for “Modbus TCP ⇄ Modbus RTU”; on the network side it exposes TCP port 502 (MBAP) and 18899 (RTU over TCP).

The USR-W610 is working and transmitting correctly, but the heat pump keeps returning errors.

Tests performed:

Modbus TCP communication on port 502 works — the HP responds — but every register I try returns “Exception code 2 (Illegal Data Address)”.

Specific tests with Modbus Poll:

  1. Function 03, Address 0, Quantity 1, Slave ID 2 → Exception 102

  2. Function 04, Address 0, Quantity 10, Slave ID 2 → Exception 102

  3. Function 03, Address 104 (register 40105 — inlet water temperature on similar models), Quantity 2, Slave ID 2 → Exception 102

It feels like the Modbus register map is either not loaded or locked on this unit.

Has anyone managed to get Modbus working on this model or knows if there’s a way to enable the map?

Thanks in advance!

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37

is there no control unit where you can hookup the modbus connection instead of direct on the unit?

38

Yes, now it’s correct. Where i find registry map?

39

you should be able to find it in the manual

40

Not in the sphera evo 2…