Three phase upper and lower limits

Question

question

groningen asked Apr 14, '24

This might be a generic question that any electrician can easily answer, but maybe some tips/experience would be nice for reference.

I am running a borehole pump (under ground ,120m below) and a water tank pump, both on three phase.

I have no issues, but our supply is not very stable (frequency is OK) as the voltage ranges from 390V up to 445V over the phases.

My question, the upper 445V, is it OK for the inverter(s) and pump(s)? If so, what is the absolute upper limit?

(Maybe for reference, our supplier states 415V with a 10% deviation, so technically 456V is still acceptable to them).

Thanks in advance

overvoltage

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Answer 1 · 2024-04-14T18:29:52Z

Alexandra answered · Apr 14 at 06:29 PM

The voltage per phase is set and rejected if a phase is higher or lower than set. Not sure if you have a grid code for where you are.

The voltages that can be accepted per phase are 180v to 265V. See the tech specs.

Theoretically that makes it an upper limit of 458v. (265v x √3) Although I don't think you want that anyway. It is so bad for motors.

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