Uk 230v and leaving the EU

[JohnW2]

I also wonder why there was a reduction of about 1V in the UPS output when there was an ~8V 'step reduction' of supply voltage?

Good question, no idea. However, the unit is (was) a double conversion unit so should hold the output voltage constant over a wide range of inputs - but there was always a small variation. I can only guess that with the reduction in input voltage, the DC bus voltage dropped, and the output followed suit as the voltage regulation in the converters isn't perfect.

It looks as if the ('average') regulation was extremely good. The daily average output voltages were perfect straight horizontal lines both before and after the 'step change' in supply voltage, the only difference being that the regulated voltage was about 1V less after the change in supply voltage. That seems odd, and it almost looks as if it was 're-configured' to a different desired output voltage at that time.

Kind Regards, John

 

[SimonH2]

It won't have been reconfigured - IIRC it's options would have been 230 or 240, not some arbitrary voltage in between. Also, from memory the old system also had a resolution of 1V in it's reporting, while the new one does 0.1V - it's possible that the output changed by just enough to flip from one reading to another. But that is just speculation.
Lastly, don't forget that the values are averaged over 24 hour periods, so while the week graph shors a fair bit of variation, that will mostly disappear in aggregation.

 

[JohnW2]

It won't have been reconfigured - IIRC it's options would have been 230 or 240, not some arbitrary voltage in between. Also, from memory the old system also had a resolution of 1V in it's reporting, while the new one does 0.1V - it's possible that the output changed by just enough to flip from one reading to another. But that is just speculation.

That sounds like a possible explanation, although it would seem a little odd that a unit which could presumably cope with input voltages well below the selected output voltage should drop its output voltage (say, from just above to just below 239.5V) in response to a fall in output voltrage which was still above the output voltage after the fall. However, I can't think of any better idea!

Lastly, don't forget that the values are averaged over 24 hour periods, so while the week graph shors a fair bit of variation, that will mostly disappear in aggregation.

Yes, I realise that, but my point was that the output voltage averaged over over a day to exactly the same figure for every day before the supply voltage fell. and the same for every day after the supply voltage fell, but with the latter being a lower figure than the former.

Kind Regards, John