Is your wall-mounted active harmonic filter malfunctioning?

Attention all power engineers! With the recent prolonged high temperatures, many factories' wall-mounted active harmonic filters (AHFs) have started to malfunction—either their compensation effectiveness has been reduced, or they have simply stopped working altogether. In fact, there are always signs before a decline in equipment performance. Learning these three self-inspection methods can save you a significant amount in repair costs!

Step 1: Check the indicator lights

Just like a car dashboard, the AHF's fault lights will “report issues.” A steady green light indicates normal operation, a flashing yellow light may indicate abnormal grid voltage, and a red light alarm requires immediate inspection of the cooling fan to ensure it is not malfunctioning. Last month, a electronics factory in Dongguan experienced overheating protection due to dust accumulation on the fan, which was resolved after cleaning.

Step 2: Listen for sounds and measure temperature  

During normal operation, only a faint humming sound should be heard. If a “clicking” noise occurs, it is likely an issue with the IGBT module. Gently touch the outer casing with the back of your hand (be careful not to burn yourself). If the temperature exceeds 60°C (feels hot to the touch), it indicates poor cooling. Immediately check if the ventilation openings are blocked by debris.

‌Step 3: Check data records‌

Modern smart AHFs come with historical data functionality. Focus on the harmonic compensation rate curve. If you notice a sudden drop from 95% to 70%, it is likely due to capacitor bank aging. For example, a injection molding workshop in Suzhou identified a bulging DC bus capacitor two weeks in advance by comparing data, thereby avoiding a shutdown incident.

For simple issues, you can handle them yourself: use a vacuum cleaner for dust removal instead of a water gun, remember to disconnect the power when replacing the filter, and apply thread sealant to loose screws to prevent vibration. However, if circuit board repairs are involved, it is safer to contact the manufacturer's after-sales service—after all, working with live electrical components is no joke!  

GEYA is a leading provider of power quality solutions, specializing in the development and manufacturing of advanced electrical devices. Our core products include Static Var Generators (SVGs), Active Power Filters (APFs), and other power control devices designed to improve power factor, reduce harmonic distortion, and enhance overall power system stability. With a strong focus on research and development, GEYA continuously innovates to deliver cutting-edge technologies that meet the evolving needs of our customers. 

As a professional manufacturer and supplier, we provide high-quality products. If you are interested in our products or have any questions, please feel free to contact us.