Profile photo of Mr-B

HI Wolfgan I believe it only makes sense if the units are “On Line” as you need seamless changeover to back-up.
The cheap units I use are by a company called Trust, these units I believe are made in Holland.(www.trust.com/14938) The model number is PW-4095T 950VA UPS. I believe this unit has sufficient capacity to run a rack with two supplies or a surface + back up PSU
I know other guys use APC and they all work fine I am sure.
I purchased my units (I have them on the office PC’s as well)through CPC/Farnell but again I am sure the same or simmilar units are available through local suppliers. The down side of these particular units is they are NOT rack mount but I live with that.
Mr. B