1. The red line is 220V live wire (L) directly connected to the live wire interface of the thermostat;
2. The blue line is the zero line (N), and the coil pipe, two-way valve, and thermostat are connected in series;
3. Green, brown, yellow, and corresponding thermostats are connected to the high, medium and low grades of fan coils respectively;
4. The black line in the figure is the "open" interface between the live wire of the two-way valve and the thermostat; the bright red line is the "close" interface between the two-way valve and the thermostat;
5. The control line is a national standard line of 7 colors and 1.0 square meters.
