ups

[puckman]

I need some help with info on one of two ups that is in service. It is rated at 3 phase 208 v input and output is 3 phase 208 v 27.5 amps. Right now i find it backs up about 5 plc on 3 different floors. I have no experience working with ups and would like to know if typically the circuits for these plc would have been brought to the ups or to a loadcenter? Can't find any breakers labeled for plc's in any of the cb panels One of the ups has a bypass switch and is off .
These ups are 20 years old.
Thanks for any info