Frequency conversion issues of pumps
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Today I noticed a fan: when the frequency converter was set to its maximum setting, the current was 20 amps and the speed was 600 rpm. However, when the frequency was reduced, the current dropped to 13 amps, but the fan’s speed dropped to only 1 rpm. Why is that? The change in current isn’t that significant – so why does the speed drop by so much? ? ?
Do you mean the voltage also changes? Could you be more detailed? I’m not very good at understanding things
Check the operating power; the voltage remains constant. If the operating power doesn’t drop much, the current won’t decrease significantly either. The fan has a minimum operating power, which corresponds to a minimum operating current.
One single data point cannot be used to determine whether the motor’s temperature rises rapidly
If the motor’s temperature rise is normal, it indicates that the motor is functioning as expected – that’s exactly how it should be! Conversely, it’s because we haven’t understood the instructions for the inverter or motor
1rpm！ So it can’t rotate anymore? Is it that this power level can’t be achieved?
Yeah, it’s hardly rotating anymore. The key is to use a 13A current; there must be some problem somewhere
This post was last edited by 1070273960 on 2017-4-24 at 11:28. The rotation speed is determined by the frequency: at a standard 50HZ, it’s at full speed; at 30HZ, it’s 60% of full speed. It seems that the current value cannot be used to determine the rotation speed
I don’t know exactly how to calculate it, but it seems that at 20 amps the rotation speed is quite high, while at 13 amps it hardly rotates at all. With such high currents, it seems like no work is being done; there must be some problem somewhere