I've only got a dedicated 120V/60A/8kW circuit here so need to make do with that. If I ever need more than 8kW/60A I'll get them to quote for 240V as well.
Why a 20A circuit? The S9 14TH/s model is rated at just under 1400W at the wall, ie about 12A. I was going to wire each into its own 15A breaker with 8 AWG. With either an individual or group RCCB/RCD.
I'm very nervous about the multi PSU idea, seems a PSU failure could kill the S9?
Parallel Miner looks interesting, thanks! Seem to open up a whole new bunch of PSUs to use.
240V cuts your amps in half. I'm running 2 S9s with their own single Apw3 on a 20amp 240v breaker with two Nema5 6 receptacles.
Edit- if you have a dedicated 120v circuit, you can very easily make it 240v. The reason it's 20amp is because that was the lowest amp 240 Breaker I saw at the store and I planned on putting 2 on it anyway. Unless it's in your wheelhouse, you might want to have an electrician make sure you have the space in your panel for the double breaker.