With two different smilar pump running at same fequency but show different amp at display of ACS580 DRIVE 37KW
Here the case, we set 40Hz for both ACS580 each both same frequency, but when run, the motor torque and motor current is different.(Half of each other example one show 48.75amp and other one show 28.27 amp only. Can I know this related to the toque?
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Basically, there are no two identical pumps, even from the same type and producer, due to the production tolerances.
From the pump characteristics, the flow of the pump is proportional to the speed and the head of the pump is proportional to the square of the speed.
Do you have these pumps working in parallel?
In case yes, most probably the first pump generates more head and takes more load, even if you provide to the both drives the same setpoint. That is due to not the same pump's characteristics itself.
You can try checking that, if you increase slightly the setpoint of the unloaded pump - it should take more load and the other one should be unloaded.
this may depend, first of all, on how the settings of the two drives have been made. Assuming that the settings are perfectly the same, the electric motors may be similar but not the same. Last but not least, the connected pumps may be different or work in different priming conditions, for example with liquids of different densities. Based on the little information you provide, it is difficult to give you other suggestions.
1 - initially when motor is moving , the torque is high and stabilize when reached at full speed (Hz).
2- Motor current depends on fluid character and any hurdle in the process line. (Back pressure ..valve opening ,closing)
3- Need to verify the motor resistance must be same, if no than motor windings is week and motor take more current.
4- Phase to phase voltage & ampere need to compare with each others by clamp meters.