On February 21, I received the company's after-sales service list. I arrived at the Luzhou Power Supply Company where the after-sales service was located that evening. After communicating with the customer, the on-site operator was led to find the cable fault point with the NDGZC-IV cable fault tester, and we quickly found the fault point. After the treatment of the fault point, I began to assemble and wire the MDXB-F-120KVA/120KV inverter series resonant withstand voltage device. During the wiring process of the equipment, I introduced the basic principle of our equipment and the precautions when using it. The frequency conversion series resonance withstand voltage device uses the series resonance principle, uses the excitation transformer to excite the series resonance circuit, adjusts the output frequency of the variable frequency controller, and makes the loop inductance L and the sample C series resonance, and the resonance voltage is the voltage applied to the sample. The frequency conversion series resonance withstand voltage device is widely used in electric power, metallurgy, petroleum, chemical and other industries, and is suitable for the handover and preventive test of large-capacity, high-voltage capacitive samples. After a review of all the wiring and the persuasion of the field personnel, we started the withstand voltage test of the cable. Start up, set parameters, automatic test, automatic pressure reduction after successful pressure, the experiment is over. Discharge and remove the wiring. The end user quickly powers up and saves the user a huge loss! Users are highly recognized for our equipment, and we are very impressed with our product technology. We are full of praise for our efficient and prompt after-sales service!