1. Clean the air filter cooling ducts and internal dust, check for loose screws, bolts, and plug-in connectors. 2. Check for short-circuit phenomena in the ground and phase resistance of the input/output reactors; they should normally be greater than several tens of megohms. 3. Inspect for corrosion on conductors and insulators; if found, clean them promptly with alcohol. 4. If conditions permit, use an oscilloscope to measure the stability of the output voltages of the switching power supply, such as 5V, 12V, 15V, 24V, etc. For aviation ground power: 2 x 36V, 1 x 400HZ inverter power supply, 2 x 115/200V power supply, 5 x 27V DC power supply, 12 x 400HZ power supply, aviation power supply.
5. Verify if the square wave waveforms of each channel in the measurement-driven circuit are distorted, and if the UVW alternating waveforms are sine waves. 6. Check for any sparking marks on the contactor's contacts; if severe, replace with a new model of the same or larger capacity. 7. Confirm the accuracy of the control voltage and conduct sequential protection action tests. 8. Confirm that there are no anomalies in the protection display circuit. 9. Confirm the balance of the output voltage of the variable frequency power supply when operating independently.
