Hi,
I have a Vivax air-conditioning and I am using a pump for taking the condensate water out. The pump which I am using has a Normal Close circuit to cut-off the AC when the pump goes defect and a Normal Open for the alarm.
My question is how can I connect the NC circuit to the AC. Diagram of the AC in the attached image.
Depends on your nc circuit. Show the components of that.
Not really… Is it 230v or 5/12v circuit? Relay?
sorry if I say something stupid, I think it is a 0 volts circuit DC which only opens if the pump goes off. I will test it with a multimeter when I’ll be home.
I am thinking that I will need a multifunction board for this system, but I don’t have enough knowledge about this.
You probably mean it’s dry contact relay.
You could take a photo of it.
Multifunction board is the easiest way to go, another option is to wire a relay to switch off mains power on L or W wire.
yes, I was planning to add a relay, but I would prefer to have it working like a thermostat and send a shit down command.
How can I check which multifunction board is compatible?
Or maybe there is a standard alarm addition available so I can have a LED showing that the pump is defective?
If I put a relay in the L wire, I am planning also to connect an LED circuit to the second NO wiring of the pump. (If the pump goes off, the LED circuit will close and LED would go on.)
If you explain better what you try to accomplish, there might be other options as well. You’re posting on esphome section, do you have some IR or wifi communication already set up?
From wiring diagram I expect your ac is Midea rebranded.
Yes, it is a Midea rebranded and the mainboard diagram is the same with mine.
I added a pump which takes the condensate water out. The pump has 6 wires like this:
3 wires for Live, Earth and Null.
3 wires for alarm system as in the second diagram (the one in Romanian).
I want to connect these 3 wires to my AC so the black and withe wire will make a NC circuit which will act as a switch when the pump will fail and this will stop the AC.
I want to connect the white and purple wire to a visual alarm (LED) so I know that the pump is the reason why the AC is shut down.
Right now I have a wifi controller connected and a standard remote control.
Multifunction board and wire controller are not present or connected, those can be added as optional.
Is it connected to HA? If yes, you could just sense that pump relay and make automation to turn off AC without wiring the pump to AC main board.
sorry, but I don’t know what HA means.
Home assistant
The wifi controller has usb stick for connection and it is connected to my home wifi router. I use and app called NetHome Plus and according to the manual it can be controlled by a HA like Alexa, but I don’t have one.
So you don’t have home assistant or esphome devices??
No, I don’t have.
You should have mentioned that in the first post, since you’re posting on home assistant forum, esphome section… 
So you need either 230V relay to cut power to L/W or that multifunction board.
Thanks and sorry for the confusion I created. Can I ask how I can choose a correct multifunction board or should I take this topic somewhere else?
You need board for your ac, it’s not easy to source. Contact Midea assistance?
Maybe relay option is easier after all.
Thank you!
If you decide to go with relay option, you could use Shelly smart switch to shut down your ac and get notification on your phone.
