[img]/forums/images/icons/tongue.gif[/img] A roomful of Automatic Transfer Switches is no place for a neophyte. I always tried to be the supportive person to the expert person, and did my best to scan the ATS with INFRARED and make sure that the jaws were transmitting currnet without overheating, and LEAVE THE TECHNICAL STUFF to the ATS expert. The complexities pertaining to AT switches are usually, but not always, centered in the controller; no big mystery there. Sometimes the units will run on "exercise mode" for A WEEK before somebody notices; or they will start when signalled by an outage, go parallel, and then never cut in. It's a very complicated process, especially with multiple units putting current onto a common bus. Having auto-standby power SEEMS simpler and easier than it actually is. In 1993 or so, there was a big earthquake in So Calif. The NUMBER OF HORROR STORIES that came out of So CA regarding standby power should have been made into a book on "how NOT to set up standby power, and how NOT to maintain the equipment. Many of the horror stories were about outfits who bought and paid for standby power, and that was the end of it. NO scheduled Maintenance, NO service program for the unit; and forget the weekly "freshen-up" run; that feature hasn't worked in years. [img]/forums/images/icons/crazy.gif[/img]