OK - I just taught myself how these relays work. They get energized with 24v DC and when energized, they close the contacts between 2 110 volt inputs so you can wire just one set for 110 volt and both sets for 220 volt. Easy Peasy. Neutral and ground continue to go to the usual neutral and ground bars. Only the hot wire goes through the relay. In essence, it is identical to a wall switch accept it gets energized to turn on as apposed to me flipping the switch.
I figured out a few things about my setup.
Both of my JVAs (powered valves) go through relays (1 each). However, the relay does nothing. It isn't hooked up to any load nor does it go to the JVA. In fact, if I unplug the relay, the JVA still works exactly the same. So I have no idea why they waste a relay for the JVAs. Each one has its own and neither is used. Of my 4 relays, 1 goes to both the pump and the heater. 1 goes to the lights, and 2 go to the JVAs. I tried to use one of the other 4 relay ports, but it appears since my unit only has a 4 relay capability (PS4), there is no way to access these relay positions. If I un-assign the relay from the JVA the JVA doesn't work anymore. Oh well.
Now the good news, I did manage to assign a JVA to the "solar" port. I connected a relay to the solar output and the relay activates when I use the solar button! Also, the better news is that I can rename the solar to anything I want. I changed it to "low voltage lights". So now all I need to do is a little rewiring to route the hot lead of the low voltage circuit through the relay and I will have control of my low voltage lights! Yayyyy!!!!!!
If anyone knows the riddle about the wasted relay positions I would LOVE to know!