Views: 9 Author: Elva，Mr.Miao Publish Time: 2025-08-22 Origin: Site
In the second half of 2023, we will work with one of food company in Jiangxi, China to carry out motor transformation, which will be used until the end of February 2024. We will solve the problems raised by customers who are dissatisfied with the equipment after on-site working condition investigation, equipment debugging and technical exchanges.
The main questions raised by on-site customers are:
1. After replacing the synchronous reluctance motor, the output has decreased compared to the previous asynchronous motor, and it is difficult to reach the amount of feed flour used in the previous workshop work.
On-site reasons: ①The on-site production process differs from the original materials.
② There's an issue with the production calculation method.
③ The motor's operating speed and torque are not as good as the original motor.
2. After the motor was replaced, the quality of the finished rice noodles produced by the motor was poor, and the manufacturer's customers often returned the products.
On-site reason: Current product process changes.
3. In special circumstances (such as power failure, driver fault), it is difficult to restart the motor. The accumulated material inside must be cleaned before it can be restarted.
On-site cause: Internal material accumulation causes the motor starting current to be too large, exceeding the maximum rated current that the starter can carry.
The extruder is used to pressurize flour into rice noodles. Its working method is as follows: the motor rotates through the belt in Figure 1 to reduce the speed in Figure 2. The reducer drives the internal screw to push the flour out and squeeze it through the die into rice noodles in Figure 3. The finished product is shown in Figure 4.
This operation is full-load, and the load current is related to the feed current of the previous process. The more material is fed into the current process, the higher the load current. Under normal process conditions, workers operating the equipment will reach the full load of the motor.
When there is no material accumulation, the starting current is relatively stable. However, in the event of material accumulation (such as restarting after a power outage or a driver failure), the starting torque is high due to internal flour and other factors, and the load fluctuates significantly, requiring a certain level of variable torque response. In this case, the current can reach or exceed twice the rated current.
The original motor starting method uses a star-delta stepped-down starting method. This is a power frequency starting method, and the operating current normally reaches the rated current of the motor. In the event of material accumulation, the overload current can reach 1.5-2 times the rated current, lasting approximately 10-30 seconds.
This on-site situation involved full-load operation, excessively high starting current, and the motor running almost constantly. If you encounter a similar situation, it's best to contact the on-site technicians and production manager to understand the motor's operating hours, current draw, and any other potential issues. Keep records and discuss solutions.
After communicating with customers these days, the following questions are raised:
①. After replacing the motor, the on-site technicians discovered that our motor's current draw was not as high as the original motor's, and was even lower than the previous motor's current draw.
②. Due to the unique operating conditions on site, the customer required the motor to reach full capacity. The on-site technicians adjusted the operating conditions (such as feed and discharge line speeds) based on our motor's speed.
③. After replacing our motor, the customer reported that the quality and output of their finished products were not up to par with those produced with the original motor.
④. Under the following special circumstances (such as power outages and motor driver alarms), the manufacturer expects the motor to restart within 30 minutes.
Note: This special situation occurs 2-3 times per month.
Based on the above problems, the following solutions were obtained during after-sales rectification and debugging:
①. Motor current: Energy-saving motor rated current: 60.9A
（As shown in the figure, the current problem raised on site is that the on-site management personnel regard the current of the cabinet door meter as the output current, while the actual motor working current is shown as the output current.）
②. Full-load motor operation: If the customer is satisfied with the energy-saving results, the relevant parameters can be adjusted to achieve a 50Hz, 1500rpm motor speed. Adjustments can be made to the on-site operating conditions in collaboration with on-site technicians.
③. Based on customer feedback, it is best to conduct a set of comparative experiments:
( As shown in the figure: These are sampling experiments based on the new and old motors at the same feed speed of 25, comparing the discharge speed, undried and dried products, product width, taste after cooking, toughness, and powder content. )
④.Fault restart: (unresolved)
There are two solutions to this problem:
a. Replace the motor with a larger drive to improve the motor's load current capability.
b. Increase the motor's startup acceleration time.
⑤.Other problems you may encounter later
a. The on-site electrical cabinet lacks heat dissipation, resulting in excessively high temperatures. Does this affect the operation of the driver?
b. Will the fully loaded motor affect the operation of the motor and driver?
c. After the manufacturer changes the formula and process, will our motor still meet their needs?
Jiangsu Huima Technology's permanent magnet-assisted synchronous reluctance motor drive system is an adjustable-speed synchronous motor drive system that utilizes ferrite-assisted excitation and reluctance torque as its primary torque source. The motor utilizes a standard asynchronous motor form factor, enabling seamless replacement. It is paired with a high-performance drive and utilizes a dedicated underlying drive control algorithm for reluctance motors, enabling efficient operation over a wide operating range, making it an excellent solution for industrial transmission systems.
Rotor loss-free, high efficiency, a wide high-efficiency range, and excellent overall operating economy.
Permanent magnet-assisted excitation reduces reactive power and increases power factor.
Ferrite permanent magnet excitation eliminates the risk of high-temperature demagnetization.
The driver features a specialized reluctance algorithm and supports open-loop vector control across all speed ranges.
The motor does not use expensive raw materials such as rare earth permanent magnets and high-grade silicon steel sheets. The driver utilizes a high-performance hardware architecture, resulting in a cost-effective IE5 energy-efficient motor drive solution with excellent economic efficiency.
To understand the on-site working conditions, you need to know the on-site motor nameplate: power, rated current, working current and control mode.
When understanding the motor power on site, it is also necessary to understand whether the motor on site has been amplified.
a. If the power has been amplified, check whether the operating current reaches the rated power of the amplified motor.
b. If the motor is operating normally, understand the motor's operating current and operating conditions, such as the starting current, whether the motor is overloaded, and the frequency and duration of overload. If the motor's starting current is excessive, or if the motor frequently requires overclocking for extended periods, consider whether the motor and driver can be amplified.
Understand the motor's rated current and measure the operating current of the motor's output wires. If the motor reaches its rated current under normal operation, consider and discuss whether its load factor should also reach full load conditions during subsequent energy-saving motor modification and commissioning.
Check the electrical cabinet to determine the motor's starting method (mains frequency, variable frequency, or soft start).
The extruder at this food company uses a star-delta reduced-voltage starter, as shown in the figure:
This is a common starting method for asynchronous motors, achieved by reducing starting current at the expense of power. Because asynchronous motors draw high starting currents during startup, large-capacity motors can be started using star-delta switching.
The star-delta starting method employed here is intended to ensure that the motor can be restarted within 30 minutes even if it is shut down and has internal material buildup. If the motor still fails to start, the manufacturer will resort to brute-force methods to force the motor to start.
①The biggest issue with the motor during this on-site installation was that the output and quality after the replacement motor did not meet the customer's satisfaction. The following issues were subsequently identified during the troubleshooting process:
a. The customer changed the raw material formula during production, and the new formula used less of the main raw material than the old one. The customer did not provide us with timely feedback on this change.
b. During discussions with us, the customer repeatedly mentioned that the current product quality was substandard and had been repeatedly returned. However, during this energy-saving retrofit, we did not have access to the customer's original finished product quality and data, nor did we conduct comparative tests of the new and old motors under the same conditions, making it impossible to make a definitive judgment or analysis.
c. The on-site commissioning was not arranged and communicated promptly. The customer repeatedly reported faults during the commissioning and operation phases, but the dealership failed to respond promptly. Consequently, when our technicians arrived on-site, they were dissatisfied with our negative response and repeatedly suggested returning to the original equipment.
② Production Commissioning Suggestions
⑴. For this type of food processing industry, obtaining raw material samples and data would facilitate sample analysis and comparison of the finished products produced with the modified motors. If this is not possible, replacing all motors on all production lines is not feasible. Instead, we should select a production line for a modified prototype and conduct comparative testing with finished products under the same conditions. This ensures that the products produced by our motors meet customer satisfaction.
As shown in the figure, this is a sampling test of products produced at the same feed speed:
After the customer is satisfied with their new motor, we will proceed with the full energy-saving retrofit of the motor.
⑵. During the production phase, we will promptly communicate with the customer and promptly address and summarize any feedback regarding production output increases, motor failures, and other operating conditions, based on customer satisfaction with the energy-saving retrofit.
