(Urgent) 7.5KW motor trips due to excessive current
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(Urgent) A 7.5kW motor in the factory trips when loaded with a single-stage centrifugal pump; the current reaches 16.8A, while the current when the motor is running without a load is 5.6A. There is no problem with the centrifugal pump itself. Could some experienced colleagues please help identify the reason for the high current in the motor? (A new motor was installed; the current when using motor A was 14.6. After operating for some time, the pump was switched to motor B as part of the routine procedure, and then switched back to the originally installed motor A. At that point, the current of motor A became 16.8, while the current of motor B also increased.)
The motor works fine when not under load; the problem lies with the pump. Try grinding the impeller.
1. Loading issues. 2. Motor aging and wear of the pump head. 3. Different motor brands result in differences in rated current
The preliminary estimate is that there is a problem with your pump.
That’s not normal; will a current of 16.8A cause it to trip? The thermal protection setting is probably too low
If the motor is working properly, there’s no need to doubt it. The pump is not working well; you didn’t say whether you repair it on a part-time basis.
Judging from your situation, the problem is likely with the pump. Check whether the pump’s impeller is not operating properly due to water scale buildup resulting from long-term use
It seems to be a problem with the pump; the head pressure at the pump outlet is too high, and there is also a misalignment between the motor shaft and the pump shaft. :)
Check whether the pump power is appropriate, and also inspect the pump itself.
The pump and motor are not matched. If it’s the original motor and pump set, was the impeller replaced? Ask the manufacturer for the specifications and have the impeller turned down in size by a bit.