Can a non-variable-frequency motor be adjusted using variable frequency? !
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The frequency shall not exceed 50HZ, and the current shall not exceed the rated current. Is frequency conversion adjustment possible?
It’s possible, but be aware that too low a frequency leads to poor heat dissipation in the motor, resulting in high temperatures; additional cooling measures may be necessary
Our sulfonation belt operates at 7-10HZ, and the feed water pump runs at 37HZ; neither of them is a variable-frequency motor
With a low frequency, the current will be very small. Will the motor overheat?
I really don’t understand what you mean. The motor overheats and gets damaged only when the current flowing through it is too high.
Although the motor operates at a low current and generates little heat, the fan’s rotation speed is too low, resulting in an ineffective cooling effect; as a result, the motor’s temperature becomes even higher
I see; the cooling fan attached to the motor operates in sync with the frequency. When the frequency is low, the fan rotates more slowly, resulting in poor heat dissipation.
The standard variable-frequency motor fan operates at the line frequency, with the spindle speed being adjustable. When a conventional motor is converted to a variable-frequency version, the fan speed also decreases
The standard variable-frequency motor fan is also a coaxial fan, with a frequency matching that of the main shaft; forced air cooling (an independent power-frequency fan) is available only as an option. There are special requirements for the insulation of the coils in variable-frequency motors. In my opinion, it’s completely fine to use non-variable-frequency motors in place of variable-frequency motors as long as the following requirements are met, and such motors offer an excellent cost-performance ratio: 1. The frequency should range between 30 and 50 Hz. 2. The driven equipment should be of the centrifugal type, as the shaft power of centrifugal machines decreases significantly as the speed drops (following a cubic relationship); therefore, reducing the frequency does not result in increased heat generation. 3. For medium and low voltage motors with low power ratings, it is best to use them below 90 kW.