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How to set up run dry monitoring on ATV630? What does DRYX parameter means?

If there is a flow switch (digital output) or flow sensor (analog) present, then run-dry conditions occurs when the flow switch gives no-flow signal or flow sensor indicates zero flow.
But when you do not have flow switch or sensor, then the only option is to use flow estimation. Flow estimation can be done based on power (for known power and defined "power vs flow" curve ATV can calcualte the flow) or based on pressure measurement (for measured pressure and defiend "head vs flow" curves ATV can calculate flow).
So flow estimation requires at least one pump curve to be entered. The best if both curves are entered.
Dry-run monitoring requires that no-flow curve is also defined in ATV, unless flow switch or sensor used. No flow curve represents situation when there is no flow, but water is present in the pump. For example valve on outlet is closed.
For no-flow curve it is necessary to define 2 points :
- Low point [NFLS, NFLP] where NFLS is low speed and NFLP is power at low speed.
- High point [NFHS, NFHP] where NFHS is high speed and NFHP is power at high speed.
Run-dry warning or fault is triggerred when estimated flow (in fact corresponds to the power that ATV measures) is below DRYX * no flow curve. Factory setting for DRYX is 70% so if the measured power is below 0.7 * no-flow curve, run dry warning or fault will appear. DRYX parameter helps to distinguish two different situations :
- no flow but water is present in a pump (power consumed is greater than in second case)
- no flow because of no water is present (power consumed in lower).
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