Wiring issue

[Limo]

I live in Egypt, I bought Learning Thermostat 3rd from USA.

I have a concealed AC, LG which works with electricity only (No gas or heaters)

I don’t know how to install the wiring

I have only 3 wires 

Red (12V)

Yellow (Signal)

Black (GND)

I need help please

[Patrick_Caezza]

@Limo 

Your current thermostat is not compatible with any of the Nest thermostats as it uses a proprietary interface