Lack of power supply (check the product's voltage against the network's), incorrect wiring, burned-out lamp, interrupted installation, short circuit between phase and load caused during installation or even a defect in an existing installation - can damage the product, poor contact in the photoelectric relay socket.

Another possibility, if the photoelectric relay does not turn on at night, is that the sensor is receiving light from another external light source, so it "detects" that it is still daytime (e.g., public lighting, signage, floodlight, etc.).

If the photoelectric relay is off in a bright environment, and you want to turn it on, you need to cover the sensor's window well and wait a few minutes (1 to 5 minutes depending on the brightness of the environment) due to the delay.