Wiring
This is somewhere to collect comments and advice on wiring, leads, plugs/sockets, etc.
The connection to the Faikin module is S21, which will usually have 4 or 5 wires, wired 1:1 from S21 to Faikin.
| Pin | Meaning |
|---|---|
| 1 | 5V - not always connected |
| 2 | Tx from aircon - 5V logic |
| 3 | Rx to aircon - 5V logic but most models accept 3.3V |
| 4 | 12V, or 14V, or some such - used to power Faikin |
| 5 | GND |
A JST EH Male 5 Way Connector is present on the Faikin.
If you have the existing Daikin wifi unit on a cable with 5 pin S21 plug, it is simply a matter of changing it to the Faikin module. However, in other cases you may need to make/obtain a cable and connect to your air-con unit, and it is possible to use both the Faikin and the Daikin wifi unit at the same time.
The S21 cable is one to one wired, i.e. Pin 1 to Pin 1. Note that Pin 5 is ⏚.
On older models, the S21 plug that is therefore needed is a JST EH Female Connector, 2.5mm Pitch, 5 Way, 1 Row.
On newer models, the S21 plug is a smaller JST PAP Male Connector with 2mm Pitch.
It is also possible, in most cases, to use jumper wire, which is a quick and easy way to connect.
If using an X10A connector, it seems pin 4 (12V) is not present, but pin 1 (5V) has enough power to run the Faikin. In that case run pin 1 (5V) from the X10A to pin 4 on the Faikin (12V). The Faikin can power from 4V to 36V on pin 4;
Some experience can be found across discussions and issues in this repo, and also on the list of confirmed working air con units page so check before ordering parts.
While adapter cables can be sourced (from PAP to EH, such as the EKRS21), it is still possible to build your own.
It is also possible to buy pre crimped cables (with PAP or EH pins on either end) in various lengths. These can be trivially inserted into the plugs.
JST crimping tools are generally expensive, other alternatives, such as the ENGINEER PA-09 or iCrimp IWS-3220M should be suitable for the purpose.
| Part | Manuf. P/N | RS | DigiKey | Comment |
|---|---|---|---|---|
| Female Connector (EH) | EHR-5 | 311-6237 | 455-1003-ND | Used on the Faikin and older S21 connectors; probably the part you will want some of |
| Female Crimp Terminal (EH) | SEH-001T-P0.6 or BEH-001T-P0.6 | 123-5946 (min qty 250) 311-6439 (min qty 100) | 455-1042-1-ND | |
| 12" EH Lead | ASEHSEH22K305 | 455-3104-ND | ||
| 6" EH Lead | ASEHSEH22K152 | 455-3103-ND | ||
| Female Connector (PH) | PAP-05V-S | 455-1489-ND | Used on some newer S21 connectors | |
| Female Crimp Terminal (PH) | SPHD-001T-P0.5 | 455-1325-1-ND | ||
| 12" PH Lead | APAPA22K305 | 455-3086-ND | ||
| 6" PH Lead | APAPA22K152 | 455-3085-ND | ||
| Jumper wire | Amazon and many others |
WARNING Messing about in your air-con unit can be dangerous with live power, and could damage the unit. Take all precautions necessary and you mess with your air-con unit at your own risk! Note, X403 is a non isolated version of S21 so if you wire to that your Faikin will be live, so needs to be inside the case somewhere, and don't wire anything while the power is on... See X403.
There have been various discussions on this - Daikin appear to have a standard connector that is S21. They seem to have this in models that even have build in WiFi modules (see image). You need a JST-EH 5 way connector for S21. However the module can also be wired to units that have an X50A connector, with slightly different cabling. The discussions have various comments on this, but please do ask.
Another approach is "jumper wires" using header pins or sockets, e.g
It is also possible to connect to the S403 connector. The proper way to do this is with a Daikin S21 adapter board, as the S403 is not isolated, and use directly could be dangerous. This link has some more details of the S403 connector, as well as issue 134.
For X50A you need power from X35A as well.
