As we all know, inverter maintenance is very important.

After servicing a large number of inverters, we have realized the importance of avoiding certain misconceptions and clearing up erroneous beliefs when it comes to using and maintaining inverters.

Do not install inverters on vibrating equipment, as this can lead to loosening of the main circuit connection screws inside the inverter, causing damage in many cases.

Wiring issues: Ensure that the input end of the inverter is connected to an air switch with a suitable current value to prevent severe damage in case of a short circuit. Never connect the “N” terminal to ground. Keep control lines as short as possible to avoid electromagnetic interference that can lead to malfunctions and damage to the control board. Use shielded cables for lengths exceeding 2 meters. Avoid installing high-current and frequently operating contactors next to the inverter, as they can cause significant interference and lead to false alarms.

Inverters that require frequent emergency stops should not rely on the inverter’s own braking system. Additional braking resistors or mechanical brakes should be added to prevent excessive stress from motor back electromotive force, which can significantly increase the failure rate.

If an inverter frequently operates at speeds below 15Hz, additional cooling fans should be installed for the motor.

Dust and moisture are the bane of inverters. Install inverters in air-conditioned rooms or enclosures with dust filters. Regularly clean dust off circuit boards and heat sinks. Before powering up a stopped inverter, use a hairdryer to blow off dust from the circuit board.

Some brands of inverters do not provide overheating protection when the cooling fan fails, leading to potential damage. If the fan makes unusual noises, it should be replaced promptly.

Factories powered by generators with unstable voltage often experience frequent inverter failures. Adding voltage stabilizers or overvoltage protection devices to the generator can significantly improve the situation.

Lightning protection is crucial. Although rare, lightning strikes can cause severe damage to inverters. Inverters used for constant-pressure water supply are particularly susceptible due to their lightning rods pointing towards the sky.

To prevent electromagnetic interference, use shielded cables for inverter input, output, and control lines. Proper shielding methods are essential to avoid adverse effects. Consider using iron pipes, adding filters, or lowering carrier frequencies to mitigate interference. Switching power supplies with field-effect transistors (e.g., K series) tend to produce more interference.

Avoid entrusting inverter repairs to inexperienced individuals, as improper repairs can worsen the situation. When fuses blow, always check for underlying issues. Novice electricians may hastily replace fuses with inappropriate materials, leading to severe inverter damage. In our experience, blown fuses often indicate module issues, but malfunctioning modules do not always cause fuse blowouts. Many inverter power modules and rectifier modules are interchangeable.

During inverter repair, we often encounter cases where factories attempt self-repairs, resulting in more severe and challenging-to-fix damages. Upon inspection, we find that repaired modules were the root cause. Faulty modules repaired using instruments can be challenging to detect, as all parameters may appear normal. However, due to poor internal wiring and inadequate sealing of transistor silicon grease, these modules may fail shortly after operation.

We hope that these insights provided regarding inverter maintenance will inspire and alert users, helping them avoid unnecessary issues.