An inverter is a type of adjustable speed drive system, utilizing variable frequency drive technology to change the frequency and amplitude of the working voltage of AC motors, thereby smoothly controlling the speed and torque of AC motors. The most common are AC/AC converters where both input and output are AC power. It has a wide range of applications, from small household appliances to large grinding machines and compressors in mines.

However, if general-purpose inverters are not used properly, operated incorrectly, or maintained untimely, failures or operational changes may occur, shortening the lifespan of the equipment. Therefore, routine maintenance and inspection work are particularly important.

1.Precautions

Operators must be familiar with the basic working principles and functional characteristics of inverters and have basic electrical operation knowledge. Before checking and maintaining an inverter, ensure that all power sources are completely disconnected, and wait until the indicator light on the inverter is completely off before proceeding.

2.Daily Inspection Items

Before powering up the inverter, check the surrounding environment's temperature and humidity. High temperatures can cause overheating alarms in the inverter, potentially damaging power components or causing short circuits. Excessive humidity can lead to internal short circuits in the inverter. During operation, pay attention to whether its cooling system is functioning normally, such as whether the air duct exhaust is smooth and if there are any abnormal sounds from the fans. Generally, inverters with higher protection ratings, such as IP20 and above, can be installed openly, while those below IP20 should typically be cabinet-mounted. Therefore, the heat dissipation effect of the inverter cabinet directly affects the normal operation of the inverter. Regularly check if the fan rotation is smooth, and if there is dust or blockage at the air intake. Check if reactors, transformers, etc., are overheating or emitting odors; if there are any abnormal noises from the inverter and motor; and if the displayed current on the inverter panel is excessively high or fluctuates too much. Also, check if the three-phase voltages and currents (UVW) are balanced.

3.Regular Maintenance

Clean the air filters, cooling ducts, and internal dust. Check if screws, bolts, and plug-ins are loose. Measure the ground and phase-to-phase resistance of input and output reactors for any short-circuit phenomena; it should generally be greater than several tens of megohms. Inspect conductors and insulators for corrosion; clean them promptly with alcohol if necessary. If possible, use an oscilloscope to measure the stability of each output voltage of the switching power supply, such as 5V, 12V, 15V, 24V, etc. Measure if the waveforms of the drive circuit's various channels are distorted. Ensure that the UVW phase waveforms are sinusoidal. Check if there are any signs of arcing on contactor contacts; replace them with the same model or larger capacity units if necessary. Confirm the correctness of control voltages, perform sequential protection action tests, ensure no abnormalities in the protection display circuit, and confirm the balance of output voltage when the inverter runs alone. It is recommended to inspect regularly, preferably once a year.

4.Scheduled Replacement of Spare Parts

Inverters consist of various components, some of which degrade or age over long-term operation, leading to inverter failures. To ensure long-term normal operation of the equipment, certain components should be replaced periodically:

5.Cooling Fans

The power modules of inverters are the most heat-generating components, requiring timely heat dissipation. Typically, the lifespan of a fan is around 10Kh—40Kh. Considering continuous operation, fans should be replaced every 2-3 years. Pay attention to whether the fan is two-wire or three-wire; do not connect wires incorrectly during replacement. Three-wire fans have one additional detection wire; incorrect connections can trigger overheating alarms in the inverter. AC fans are usually 220V or 380V; ensure correct voltage ratings during replacement.

6.Filter Capacitors

Middle circuit filter capacitors, also known as electrolytic capacitors, mainly serve to smooth DC voltage and absorb low-frequency harmonics. Their lifespan is approximately five years under normal conditions. It is recommended to check the capacitance annually; replace if the capacity decreases by more than 20%. To ensure your equipment operates safely and stably, please invest time and effort into maintaining your inverter.

Changsha Sunye Electric Co., Ltd. (established in 2010) and Shenzhen Sunye Electric Co., Ltd. (established in 2002) are national high-tech enterprises integrating R&D, manufacturing, and sales of inverters, industry-specific all-in-one machines, servo drives, and new energy products.
Sunye Electric owns independent intellectual property rights, with products certified by national authoritative institutions and holding multiple software copyrights and IP certificates. Each year, significant investment is made in research and development of new technologies and products, resulting in numerous approved patents and software copyrights. The company possesses core platform technologies such as construction hoist drivers, high-performance vector inverters, servos, and permanent magnet synchronous motor controls. Medium- and low-voltage inverters and servo drives are widely used in industries such as lifting machinery, stone processing, HVAC, machine tools, metal products, wire and cable, plastics, printing and packaging, textile and chemical fibers, building materials, metallurgy, coal mining, municipal services, and automotive manufacturing. Guided by the philosophy of “Innovation, Technology, Strength,” driven by the corporate spirit of “Unity, Progress, Pragmatism, Innovation,” and adhering to the business principle of “Sincerity and Excellence, Mutual Benefit and Coexistence,” Sunye Electric is committed to providing premium products to customers across various industries through its quality policy of “Implementing total quality management, continuous improvement, and pursuing zero defects.”

Address: Sunye Electric Industrial Park, No. 669 Xinsheng Road, High-Tech Zone, Changsha City

Tel/Fax: 0731-89932666 0731-89932688

Business Phone: 400-0755-731

Technical Support: 400-0755-731