Why a UPS is mandatory for important equipment

Apcupsd logs taken from a client site in an industrial estate with frequent brownouts/power interruptions.




2013-01-29 16:58:28 +0800  Power is back. UPS running on mains.
2013-01-29 16:58:39 +0800  Power failure.
<snip dozens of lines >
2013-01-29 17:29:00 +0800  Power failure.
2013-01-29 17:29:02 +0800  Power is back. UPS running on mains.
2013-03-01 16:00:00 +0800  Power failure.
2013-03-01 16:00:01 +0800  Power is back. UPS running on mains.
2013-03-02 06:04:39 +0800  Power failure.
2013-03-02 06:04:41 +0800  Power is back. UPS running on mains.
2013-03-07 11:54:37 +0800  Power failure.
2013-03-07 11:54:41 +0800  Power is back. UPS running on mains.
2013-04-01 08:51:26 +0800  Power failure.
2013-04-01 08:51:28 +0800  Power is back. UPS running on mains.
2013-05-14 15:56:48 +0800  Power failure.
2013-05-14 15:56:54 +0800  Running on UPS batteries.
2013-05-14 15:58:08 +0800  Mains returned. No longer on UPS batteries.
2013-05-14 15:58:08 +0800  Power is back. UPS running on mains.

As can be seen, if there was no UPS, the server could have gone down multiple times per month. If the server was set to power on automatically, the server PSU could have been stressed to blowing point on the 29th of Jan, since power was going off/below normal threshold frequently.