The top left corner of the intelligent lighting module L, N for zero test wiring, the power supply, there are some manufacturers do power supply on the module, which is a kind of unprofessional, disadvantages 1: unsafe, power source with control module for easy fever, leave a safe hidden trouble, we relay control modules are stronger elv isolation. Drawback 2: waste of space, the power part will occupy at least 2P empty open space. Drawback 3: waste of cost. We can supply power to about 30 control modules with one power module.