Or should I do,
30Amps Dual Pole => 240?
Again I want to run 3 X S4.
Do you wish to run them on the same circuit or dedicated breaker for each antminer?
You will have about 3400 Available Watts on each pole with a 30amp dual pole breaker totaling about 6800 Watts of available power. Three ant miners will demand 4200W minimum. Just Make sure to run 10ga wire, I usually run 10-3 to mark my second pole with red as opposed to white, electricians preference. Just be sure that your Panel can handle it, check the total load vs. total available amperage to be sure.
If you decide to put an antminer on each circuit, you can run them on 12 wire, but you will need dual pole 20-amp breakers.
Hope this information helps.