Common Fault Diagnosis for Solar Street Light Controllers: A Must-Read for Maintenance Personnel

Friends involved in the maintenance of solar street lights know that although the controller is small, once it fails, the entire street light system can be paralyzed. Often, the faults are quite simple and can be diagnosed and resolved by oneself without the need for professional maintenance personnel. Today, we have compiled the 5 most common controller faults, along with detailed troubleshooting methods and solutions, making it easy even for beginners.

1、The street light turns on during the day and off at night.
This is the easiest problem to diagnose. The high probability is that the controller's light control function has malfunctioned. First, check the light sensor on the controller. See if it is blocked by dust, leaves, bird droppings, etc. Blockages can cause the sensor to misjudge, thinking that the day isn't over yet, and therefore it won't start discharging to light the lamp. The solution is simple: wipe the light sensor with a dry cloth to remove any obstructions. This usually restores normal operation. If it still doesn't work after cleaning, the light sensor might be damaged, requiring replacement of the sensor or the entire controller.

2、 The street light doesn't turn on, and the controller's indicator light is off.
This situation is generally a power supply issue. First, check if the controller's wiring connections are loose or disconnected. Pay special attention to the battery and solar panel wiring terminals. Outdoor equipment exposed to wind and rain over long periods is prone to loose connections. When troubleshooting, first turn off the power, then check each wiring terminal one by one to ensure they are secure, with no looseness, disconnection, or reverse polarity connection (reverse polarity can burn out the controller). If the wiring is fine, next check the battery voltage. Use a multimeter to measure the battery voltage. If the voltage is below the protection threshold (for example, below 10.8V for a lead-acid battery), it indicates the battery is depleted and needs charging before further testing. If the battery voltage is normal but the controller still doesn't light up, the controller itself may be damaged and require replacement.

3、Insufficient charging, the battery never gets fully charged.
This issue is mainly related to the controller and the solar panel. First, check if the solar panel is shaded or dirty, for example, covered by dust or snow. This affects power generation efficiency, leading to insufficient charging. Next, check the controller's charging mode. If it's a PWM controller, its charging efficiency is inherently lower in low-light environments; consider replacing it with an MPPT controller. Additionally, check the controller's temperature compensation function. In low-temperature environments, controllers without temperature compensation can lead to insufficient charging voltage, preventing the battery from getting full. In this case, a controller with temperature compensation function is needed.

4、The street light's brightness is unstable, flickering on and off.
This is highly likely a problem with the controller's dimming function or a mismatch in load power. First, check the controller's dimming settings. See if the brightness level was accidentally adjusted, or if the staged dimming settings are incorrect. Simply reset the dimming parameters. If the settings are fine, next check the power of the LED lamp to see if it exceeds the controller's rated load power. Exceeding the load power can trigger the controller's overload protection, resulting in unstable brightness. The solution is to replace the controller with one that matches the power rating or reduce the connected load.

5、Remote control malfunction, unable to view status.
Many smart controllers nowadays support remote management. If remote control fails, first check if the controller's communication module (4G/NB-IoT) is functioning properly. Check if the SIM card is out of credit or if the signal is good. Remote areas outdoors may have weak signals, which can cause remote communication failure. Try adjusting the controller's installation position to ensure good signal reception. If the communication module seems normal, check the software settings on the mobile app or computer for any connection anomalies. Restarting the software or re-binding the device might resolve it.

Finally, a maintenance tip: For outdoor solar street light controllers, it is recommended to inspect the wiring terminals quarterly, removing dust and debris to prevent water ingress and short circuits. Check the light sensor and communication module annually to ensure they are functioning correctly. Measure the battery voltage every six months and promptly replace aging batteries. This will effectively reduce controller failures and extend the overall lifespan of the street light system. If you encounter a complex fault that you cannot diagnose yourself, it is advisable to contact professional technical personnel to avoid blind operations that could lead to equipment damage.