DEC 874-A Power Conditioner

Greetings to all, and here's to 2006! My first post, though I have skulked for months...still, consider me a PDP newbie... I've recently acquired a fully functional PDP-11/23plus with the idea that I'd re-acquaint myself with RSTS/E which happened to be the first system I was actually paid to program on. Trouble is, it was a short stint with this local VAR, and it was nearly 30 years ago! I don't even remember what the systems were exactly, though I think they were 11/40s. Stangely, these systems were in blue cabinets (did DEC ever do blue?), with none of the typical maroon or red PDP-11 signature color...that is until the LSI models started showing up in white, which is what I've got. Anyway, I'm now happily in the process of re-assembling the system and preparing for my first power up since getting it home. The configuration I have is in a double-wide 40" tall rack unit. Each rack or 'bay' between the three uprights has a 874-A power conditioner / power-strip unit that I'm trying to understand. I haven't been able to find any references to this component. Though I could just replicate the configuration that it had before being relocated (switches, wiring, etc.), which I have plenty of photos of, I'd like to understand this compenent better. Since I have a double-wide cabinet, I've got two of these units that are linked together with a 3-conductor cable, each end plugged into one of the four "Power Control Bus"-labeled sockets. One 874-A also has another connection from a second "PCB" socket to the the 11/23+ processor box. My guess is this line somehow is controlled by the front panel AUX ON/OFF switch. Also, each of the 874-A units has a small 3-position toggle switch: 'Remote On', 'Off', and 'Local On'. Before I go much further with experimenting on my own, I wonder if anyone here knows these units and can offer some info about how these units tie together and what settings do what. Comments? J.