[Al Skierkiewicz]

Steve,
I really recommend that teams do not tin wires for several reasons. In the case of the WAGO connectors, the manufacturer has designed the terminals for stranded specifically or wire terminated with their ferrules which are square. For other screw type terminals, the tinning prevents the screw from biting in a uniform way and if the wire were to turn, the connection would be loose. In the new hardware, tinning would again prevent a good contact and tight retention in the push type contacts. I only tin wires that are intended to be soldered into terminals meant for solder.