I am running one S1 Antminer and everything is doing well. I want to add a second S1 along with a switch for the router and a surge protector. What is the best way to shut down and add this hardware and is there a good time to do it?
ssh into your S1 via some terminal program (like putty on Windows) and type this:
That will shut it down. Then just unplug it. Note that you'll have to assign IP addresses to each of the S1s, since they use 192.168.1.99 by default, and you can't have two units with the same IP on your network.