If you're seeing much higher than 11A power draw at 120V, check your power cable, make sure it's not getting warm. One unit drew 14A on an 18 gauge cable, causing the cable to get a little warmer than i was comfortable with. Switched to a 16 gauge cable and it dropped to 11A and the cable stays cool.
Might sound silly. How does the AWG of power cable impact how much it pulls? Will 14 AWG be even better and will pull lower than 11 A?
Lets say you draw 1400W from the wall which at 120V is 11.6A. (1400W/120V=11.6A). But in this case the 18 gauge wire is too thin which is making it act as a resistor (which is why it gets warm / hot to the touch). Because the wire in this case is acting as a resistor it will drop some voltage under load. Let's say it drop's 15V making the line voltage at the miner 105V. The miner still pulls 1400W regardless (1400W/105V=13.3A). So the amperage went up to compensate for the drop in voltage and the wire / PSU gets hotter as they are dissipating that extra energy as heat.
This is why many recommend 240V, as 1400W/240V=5.8A. The energy consumption of 1400W is the same (actually a bit less as the PSU is slightly more efficient at higher votlages), but the amperage is much lower which means you can fit more devices on a single circuit.
Basically if your power cable is warm, you are dropping voltage and wasting electricity. Not to mention creating a potential fire hazard. For this miner i would say 16 gauge power cables are a minimum requirement at 120v. At 240V 18 gauge should suffice just fine.