On Saturday 15 Nov 2014 14:22:47 Thanasis wrote:
> on 11/15/2014 03:54 PM Bruce Schultz wrote the following:
> > If the UPS battery has not run flat before the mains power is restored,
> > I see no reason why a UPS should kill the output power.
> 
> The PC has an option in BIOS to "Power On" when the mains power is
> restored to it, without any need to press any button.
> So, once the UPS has initiated a shutdown to the PC, the PC will
> shutdown, and if the mains power is restored (to the UPS) shortly after
> the PC has shutdown, how will the UPS make the PC come back on, unless
> it cuts (kills) the power to PC's cord, and then restores it after a few
> seconds.
> See the link Mick posted in his reply:
> http://www.apcupsd.com/manual/manual.html#arranging-for-reboot-on-power-up

On the same page it lists a number of tests you can perform:

http://www.apcupsd.com/manual/manual.html#testing-apcupsd

Have you been through them and in particular the "Full Power Down Test"?  If 
yes, did you wait long enough after the PC has powered down, for the UPS to 
also switch off (you can affect the overall waiting time by setting a shorter 
TIMEOUT value, rather than waiting for the batteries to go flat). 

If this does not get you somewhere, I recommend you post to the  
nut-upsuser@lists.alioth.debian.org (you'll need to register first).  The 
developers and contributors are offering friendly advice and are very 
knowledgeable on all things UPS related, including annoying bugs with firmware 
that defeat reason.

PS. The services I listed running are particular to my UPS, I expect different 
to your APC unit.

-- 
Regards,
Mick