Motor modification with inverter

The most effective scenario for saving energy and reducing consumption by replacing motors with frequency converters in chemical processing plants is when the load (such as fans or pumps) requires frequent adjustment of flow/pressure, and the original system relies on valves, dampers, or bypass throttling for control, resulting in an actual load rate that is significantly lower than the rated value (often <70%).

The people upstairs have made some very valid points; heat dissipation and explosion prevention are indeed the most easily overlooked \"hidden barriers\" in chemical plant renovations. I’d like to add some personal experience: Cost estimation – for a regular small to medium-sized motor (for example, one with a power rating of 11 kW or less) that is to be equipped with an inverter, the cost of the inverter itself ranges from around 3,000 to 8,000 yuan, depending on the brand and protection level. If an additional independent fan needs to be installed, explosion-proof junction boxes have to be replaced, and on-site explosion-proof modifications are required, the total cost could exceed 15,000 to 20,000. It is recommended to first obtain the specifications from the motor nameplate and the equipment list, and then seek quotes from suppliers with chemical processing qualifications, as there are significant differences depending on the operating conditions. When selecting a frequency converter, don’t consider only the price: in chemical processing plants where frequent start-up and stop-up operations are required or precise speed control is needed (such as in pumps and fans), the control method of the frequency converter (V/F control, vector control) as well as its overload capacity must also be appropriate. Additionally, the harmonics generated by the inverter may affect instruments or the host computer; it is advisable to verify whether input and output reactors or filters are included when selecting the device. Don’t forget the review process: Chemical process upgrades usually involve Change Management (MOC), requiring approval from multiple departments such as process engineering, equipment, electrical systems, and safety. It’s best to communicate in advance with the workshop supervisor and the Safety and Environment department to confirm whether the existing power distribution capacity and cable cross-sectional area are sufficient, so as to avoid frequent tripping issues only after the upgrades are completed and testing begins. The information above is based on common industrial scenarios; for specific recommendations, it is advisable to consult qualified electrical engineers or equipment suppliers using the motor parameters and information on the type of area in question, and to follow their official assessments. Wish the renovation success!