Erland Moller wrote:
Per Jessen schreef:
Erland Moller wrote:
Don't forget that with a bigger/more expensive UPS, most of the time you have the advantage of hot-swappable battery's and/or a bypass function plus the ability to shut down more than one server if things go wrong. Most of the small UPS's have to be shut-down to swap the battery's. Furthermore with the big UPS's the battery voltage is higher resulting in low amp's on the battery's resulting in longer lifetime.
Erland, I think you're talking very large UPS'es here - I haven't seen anything less than 25kVA with hot-swappable batteries. Bypass mode yes, but hot-swappable batteries is another level.
/Per
I beg to differ. I have at home a Powerware 4000 VA UPS with external/hot-swappable battery's. At the company i work i have tested/replaced a lot of batery-packs from ups's ranging from 1500 VA up to 40 KVA Every company that delivers ups's should use hot-swappable battery's since this is the weakness of a UPS.
That would depend on whether you can tolerate a planned shut down or have other protection measures. For example, I have an IBM Netfinity server. It can have up to 3 redundant power supplies, but can run on one. If I have to kill one AC feed to change a battery, so what? I still have 100% power redunancy and could tolerate another failure. Multiple power feeds are common in critical equipment. -- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org