Nut upsuser - Oct 2023 - My Back-UPS RS 1000 went haywire, any ideas?

Hi,

I am sorry for possible offtopic as this question is not quite 
NUT-related but I cannot imagine any other place with people of such 
deep and intimate knowledge of UPS behavior.

One day all of a sudden my APC Back-UPS RS 1000 refused to go online 
(green led) even though mains was connected. I used upsc to see what is 
going on, and ups.status was "OB DISCHRG", battery.charge was slowly 
decreasing and input looked like this

input.sensitivity: medium
input.transfer.high: 264
input.transfer.low: 194
input.voltage: 182.0
input.voltage.nominal: 230

I took an external voltmeter and made sure that actual input voltage is 
around 223 V and is not changing. However, each successive run of upsc 
indicated drastically different "input.voltage", arbitrarily jumping 
from 160 V to 280 V. Besides this, no other values seemed abnormal.

Is this something that can be fixed in-house? Or something widely known 
about this particular model and/or vendor? I'm puzzled. Please, advice. 
Sorry for the offtopic once again.
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battery.charge: 49
battery.charge.low: 10
battery.charge.warning: 50
battery.date: 2001/09/25
battery.mfr.date: 2007/07/20
battery.runtime: 6339
battery.runtime.low: 120
battery.type: PbAc
battery.voltage: 24.9
battery.voltage.nominal: 24.0
device.mfr: American Power Conversion
device.model: Back-UPS RS 1000
device.serial: 8B0729R16742
device.type: ups
driver.name: usbhid-ups
driver.parameter.pollfreq: 1
driver.parameter.pollinterval: 1
driver.parameter.port: auto
driver.parameter.synchronous: auto
driver.version: 2.8.0
driver.version.data: APC HID 0.98
driver.version.internal: 0.47
driver.version.usb: libusb-1.0.26 (API: 0x1000109)
input.sensitivity: medium
input.transfer.high: 264
input.transfer.low: 194
input.voltage: 182.0
input.voltage.nominal: 230
ups.beeper.status: disabled
ups.delay.shutdown: 20
ups.firmware: 7.g9a.I
ups.firmware.aux: g9a
ups.load: 1
ups.mfr: American Power Conversion
ups.mfr.date: 2007/07/20
ups.model: Back-UPS RS 1000
ups.productid: 0002
ups.realpower.nominal: 600
ups.serial: 8B0729R16742
ups.status: OB DISCHRG
ups.test.result: No test initiated
ups.timer.reboot: 0
ups.timer.shutdown: -1
ups.vendorid: 051d

Is the battery old? PbAc ones usually last for 2-3 years and then degrade.
Should be a field-replaceable part.

Some 20 years ago I had an APC BackUPS become a glorified power strip every
few years, so when the wall power disappeared - load went down immediately.
It was also beeping about battery replacement (but in the closet, was not
often noticed quickly). This is also a way for you to check if the
situation is something like that - pull the cable and see if it holds up
for any non-trivial time ;)

Otherwise, maybe electronics went bad over time (dried capacitors etc.) so
the controller and its sensors are in fact going haywire. This might also
be replaceable, if you're good with soldering (or can find/hire someone who
is) or if warranty repair is still an option.

Finally, the UPS might partake in self-calibration, where it deliberately
discharges itself to check how long the battery holds up your load (maybe
the charge-level cycle also lets it keep the internal chemistry healthier).
Usually it powers itself back up from mains in the nick of time before it
would otherwise shutdown, if it guessed the timing correctly (e.g. battery
did not age too poorly since last test, and the load did not change too
much).

Hope this helps,
Jim Klimov


On Sat, Oct 28, 2023 at 5:28?PM Gennadiy Poryev via Nut-upsuser <
nut-upsuser at alioth-lists.debian.net> wrote:
> Hi,
>
> I am sorry for possible offtopic as this question is not quite
> NUT-related but I cannot imagine any other place with people of such
> deep and intimate knowledge of UPS behavior.
>
> One day all of a sudden my APC Back-UPS RS 1000 refused to go online
> (green led) even though mains was connected. I used upsc to see what is
> going on, and ups.status was "OB DISCHRG", battery.charge was
slowly
> decreasing and input looked like this
>
> input.sensitivity: medium
> input.transfer.high: 264
> input.transfer.low: 194
> input.voltage: 182.0
> input.voltage.nominal: 230
>
> I took an external voltmeter and made sure that actual input voltage is
> around 223 V and is not changing. However, each successive run of upsc
> indicated drastically different "input.voltage", arbitrarily
jumping
> from 160 V to 280 V. Besides this, no other values seemed abnormal.
>
> Is this something that can be fixed in-house? Or something widely known
> about this particular model and/or vendor? I'm puzzled. Please, advice.
> Sorry for the offtopic once again.
> _______________________________________________
> Nut-upsuser mailing list
> Nut-upsuser at alioth-lists.debian.net
> https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/nut-upsuser
>
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Gennadiy Poryev via Nut-upsuser <nut-upsuser at alioth-lists.debian.net>
writes:
> I took an external voltmeter and made sure that actual input voltage
> is around 223 V and is not changing. However, each successive run of
> upsc indicated drastically different "input.voltage", arbitrarily
> jumping from 160 V to 280 V. Besides this, no other values seemed
> abnormal.
>
> Is this something that can be fixed in-house? Or something widely
> known about this particular model and/or vendor? I'm puzzled. Please,
> advice. Sorry for the offtopic once again.
I would guess one of

  Something is flaky and the power is not as good as it seems, or the
  wiring from power strip where you are measursing to UPS input is off.
  I would definitely remove and re-seat everything you can.

  The circuitry that senses voltage is off.

  The neutral is open and then all bets are off.  Did you measure hot to
  neutral, hot to ground, neutral to ground?  You say 230 and I'm
  guessing this is in a place with 230V outlets.  (In the US we have
  125V with neutral and 250V phase to 180-out-of-phase phase, for
  "single phase" service.)

  So actually, check the neutral inside the equipment.  Power it all
  down and unplug and be super careful as UPS devices have power inside
  when they are off and unplugged.