Thanks to the help here, I got a properly functioning switching system. What I ended up doing was have the electrical engines feeding into a redstone energy cell with a structure pipe attached and a Gold OR gate on it. I then set it up as indicated early on, with red alloy wire running to all the electrical engines and the energy cell, and the cell set to not output power when there is a redstone signal. This allows the cell to fill completely. This cell then feeds into another cell which feeds machines. Works great.
Now I have a new 'challenge'. I added 'Additional pipes' to my server and client so I can wirelessly 'beam' BC energy to my quarry. The problem is, while I haven't hit bottom yet since I started the quarry, I suspect when I do, it may stop using power, fill up and melt pipes. I tried using the 'power traversing' to keep power flowing, and when it filled up, it turn on redstone current and stop power output. That didn't work, as I guess it can't tell the difference between power flowing and power full in the pipes. In hindsight, that probably woudln't have worked right anyway because once power was shut off, it would have to be manually restarted.
Can anyone thing of a way that I could make the cell stop outputting power when the pipe fills up before it explodes?