[ls1nova71]

A trinary switch has 3 sets of contacts inside of it, one for low pressure cut off, one for high pressure cut off and a third for an electric fan. A binary switch just has two high and low contacts in it. To wire it up, the compressor would wire the same, one wire from the A/C switch on the dash would be on the high/low set of wires and then would go to the compressor. Then to wire the fan, you would ground one side of the switch and the other would go to the fan relay so it would get grounded whenever the pressure dictates the fan should be on. I cant say what wires are what, but they should be labeled or come with some kind of instructions saying what wire is what. As for what switch to use, all i have ever used were VA switches, but that one you linked looks like its the same thing, and its possible VA just puts their name on them.