[Nut-upsdev] NUT namespace: RFC for new variable addition

[Jim Klimov]

On June 14, 2017 2:38:16 PM GMT+02:00, Arnaud Quette <arnaud.quette at gmail.com> wrote:
>(hmmm, finally hitting the Sent button...)
>
>2017-05-24 13:56 GMT+02:00 Jim Klimov <jimklimov at cos.ru>:
>
>> On May 24, 2017 1:08:09 PM GMT+02:00, Charles Lepple
><clepple at gmail.com>
>> wrote:
>> >On May 24, 2017, at 5:11 AM, Arnaud Quette <arnaud.quette at gmail.com>
>> >wrote:
>> >>
>> >> Hi all,
>> >>
>> >> here is another one, related to ATS (automatic transfer switch)
>this
>> >time.
>> >>
>> >> in order to track "dephasing" between input sources (1 and 2), I'd
>> >like to add a new variable: "input.phase.shift"
>> >>
>> >>
>> >> Details and implementation can be found on:
>> >> https://github.com/networkupstools/nut/pull/433
>> >>
>> >> Comments and feedback warmly welcome.
>> >
>> >I don't think "dephasing" is common usage, but "phase shift" should
>> >suffice.
>> >
>> >Also, how does this apply to 3-phase systems? Is it nominally 120
>> >degrees?
>> >
>> >Strange that this has not come up before.
>> >_______________________________________________
>> >Nut-upsdev mailing list
>> >Nut-upsdev at lists.alioth.debian.org
>> >http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/nut-upsdev
>>
>> It was my impression too. However it seems the 'phase shift' usually
>> refers to lag between Amperage and Voltage waves, while this issue is
>(if I
>> get it correctly) about two separate ATS inputs fluctuating on their
>own
>> different clock-offsets. Should be same freq (50 or 60) though, or
>likely
>> assumed so - which might not be guaranteed in real life either ;) On
>the
>> other hand, if the freqs differ, this reported skew degree will vary
>over
>> time (if detected and reported honestly)...
>>
>
>Jim is right, this is very tied to ATS. I don't see that applying to
>3ph
>UPS, since there is only 1 source.
>The point for ATS is that a source may be the main, and the other a
>UPS.
>Hence the potential phase shift.
>The nominal value is 0
>
>cheers,
>Arno

http://www.apc.com/us/en/faqs/FA156201/ explains a bit of the hassle
--
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