APC UPS won't restart after power outage


Installed new APC Back-UPS CS 350 on single server running openSUSE 11.2 64-bit and configured NUT 2.4.1 (SUSE package) according to instructions.

When testing, NUT shuts down the server correctly and instructs the UPS to power down. UPS does so after some 20s delay, everything without errors. But after restoring main power, even after waiting for 1/2h UPS does not by itself turn on again, all LEDs are dark. One has to manually press the UPS’s power button, which makes server and monitor run again immediately.

What could be wrong that prevents UPS from turning itself on again?

Below output of upsc:

battery.charge: 95
battery.charge.low: 10
battery.charge.warning: 50
battery.date: 2009/10/11
battery.mfr.date: 2009/10/11
battery.runtime: 1237
battery.runtime.low: 180
battery.temperature: 29.2
battery.type: PbAc
battery.voltage: 13.6
battery.voltage.nominal: 12.0
driver.name: usbhid-ups
driver.parameter.pollfreq: 30
driver.parameter.pollinterval: 2
driver.parameter.port: auto
driver.version: 2.4.1
driver.version.data: APC HID 0.93
driver.version.internal: 0.34
input.voltage: 122.0
input.voltage.nominal: 120
output.voltage: 115.0
output.voltage.nominal: 120.0
ups.beeper.status: enabled
ups.delay.shutdown: 20
ups.firmware: 805.q8.D
ups.firmware.aux: q8
ups.load: 49.0
ups.mfr: American Power Conversion
ups.mfr.date: 2009/10/11
ups.model: Back-UPS CS 350
ups.productid: 0002
ups.serial: 4B0941P71480
ups.status: OL CHRG
ups.test.result: No test initiated
ups.timer.reboot: 0
ups.timer.shutdown: -1
ups.vendorid: 051d

Thanks a lot for any hint!

Came to know that this UPS (APC Back-UPS CS 350) is an entry-level UPS targeted at small desktop systems which does not support automatic restarting after power failure, when mains return.

Ok, it turned out, this UPS does support automatic restarting after power failure, when line power returns, but NUT package’s driver does not support this UPS (yet).