[Nut-upsuser] problem with output voltage on a mustek ups

pmjorge at lip.pt pmjorge at lip.pt
Thu Mar 6 21:18:34 UTC 2008

Quoting Arjen de Korte <nut+users at de-korte.org>:

>> My problem is that sometimes the UPS is running OK, but when the
>> message "UPS is trimming incoming voltage" appears on knutclient (i.e.
>> OL TRIM in nut), I have something like
>> Input Voltage
>> 	241.1
>> Output Voltage
>> 	202.0
>> 	nominal 220.0 ???
>> This output voltage is too low! I  think power spikes may be better
>> than using this voltage.
> I don't think so. Unless the input voltage is exceptionally low (but then
> the UPS would switch to battery), the power supply will not be hurt by it.
> An input voltage that is too high, will hurt it, so I wouldn't worry about
> it.

Do you mean the computer's power supply? But it is supposed to run on
220-230V not on 202V! Isn't this a problem?

>> I don't know if the problem is the UPS or from communication with it.
>> Can you please help me checking  this? I have search on the web and on
>> the nut mailing-lists, but I didn't found anything.
> NUT has no way to control is the UPS is using BOOST/TRIM, this is
> something that the UPS decides all by itself. So there is nothing we can
> do about it, complain to Mustek if you feel this is wrong.

I thought that issuing
   upscmd -u admin -p password mustek reset.input.minmax
might make the UPS "re-think" if it should trim the output voltage,
but I seems I was wrong. It does nothing.

I will certainly complain to Mustek, as they say 220-230V output.

> Best regards, Arjen

Thanks again,

> --
> Eindhoven - The Netherlands
> Key fingerprint - 66 4E 03 2C 9D B5 CB 9B  7A FE 7E C1 EE 88 BC 57

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