Marcin's rootprompt blog – /dev/web0

image (C) APC

Hi! Here’s another UPS review 😉 I am not an UPS tester by profession, but this topic seems to be around me recently, caused by various opportunities. This time I am playing with APC Smart SC1000 tower/rack-mount unit, and it’s nut interoperation.

The unit comes with two data cables, one is RS-232 to RS-232 and the other is RS-232 (ups side) to USB (host side). The USB device is detected as:

067b:2303 Prolific Technology, Inc. PL2303 Serial Port

So it is actually a serial device. The driver to use is apcsmart with one significant setting:

port = /dev/ttySx
port = /dev/ttyUSBx
port = /dev/serial/by-id/usb-Prolific_Technology_Inc._USB-Serial_Controller-if00-port0

Remember that the serial device must be accessible by the uid which nut driver is running with. Try an udev rule.

Here’s the upsc output:

# upsc apc1000
battery.alarm.threshold: 0
battery.charge: 012.0
battery.charge.restart: 00
battery.date: 10/06/11
battery.runtime: 600
battery.runtime.low: 120
battery.voltage: 24.44
battery.voltage.nominal: 024
device.mfr: APC
device.model: Smart-UPS SC1000
device.serial: 5S1141T08304
device.type: ups
driver.name: apcsmart
driver.parameter.pollinterval: 2
driver.parameter.port: /dev/serial/by-id/usb-Prolific_Technology_Inc._USB-Serial_Controller-if00-port0
driver.version: 2.4.3
driver.version.internal: 2.03
input.frequency: 50.00
input.quality: FF
input.sensitivity: H
input.transfer.high: 253
input.transfer.low: 208
input.transfer.reason: simulated power failure or UPS test
input.voltage: 242.0
input.voltage.maximum: 242.0
input.voltage.minimum: 242.0
output.voltage: 242.0
output.voltage.nominal: 230
ups.delay.shutdown: 060
ups.delay.start: 000
ups.firmware: 737.3.I
ups.id: theups
ups.load: 011.0
ups.mfr: APC
ups.mfr.date: 10/06/11
ups.model: Smart-UPS SC1000
ups.serial: 5S1141T08304
ups.status: OL
ups.test.interval: 1209600
ups.test.result: NO

Here’s the upsrw output:

# upsrw apc1000
[battery.date]
Battery change date
Type: STRING
Value: 10/06/11

[ups.id]
UPS system identifier
Type: STRING
Value: theups

And here’s the upscmd output:

# upscmd -l apc1000
Instant commands supported on UPS [apc1000]:calibrate.start - Start run time calibration
calibrate.stop - Stop run time calibration
load.off - Turn off the load immediately
shutdown.return - Turn off the load and return when power is back
shutdown.stayoff - Turn off the load and remain off
test.battery.start - Start a battery test
test.battery.stop - Stop the battery test
test.failure.start - Start a simulated power failure
test.panel.start - Start testing the UPS panel

Tested and working commands: shutdown.return, test.battery.start, test.failure.start, test.panel.start; other commands not tested – I have learned a lesson recently.

And as before, here are a few graphs displaying charging and discharging data with ups.load about 13-15:

Fig. 1 Charging - 12 hours - data with battery.runtime

The runtime seems to stabilize after about 6 hours, however battery voltage is further increasing slowly.

Fig. 2 Charging - 12 hours - focus on battery.charge and battery.voltage

A discharge cycle has run for about 54 minutes and it was interrupted manually – battery voltage was going really low and I did not want to risk it’s life. However I did one or two discharge cycles before this plotted version, and the UPS successfully shut-off itself with a higher battery.voltage. Therefore I could have been safe, but did not want to take any risk anyway.

UPS started to signal low-battery (LB) after 39 minutes (~2350 sec), but lasted at least 15 minutes after. This may or may not be your case, my previous run proved about 5 minutes on LB before automatic shut-off.

Fig. 3 - Discharging - data with battery.runtime

Fig. 4 Discharging - focus on battery.charge

Fig. 5 Discharging - focus on battery.voltage

To summarize – it is a very good UPS, behaves reliably and it’s interoperation with nut is just excellent with apcsmart driver.

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