Are you overclocking your Avalon? Then it will run around 700 watts.
and this is the biggest reason to have k-watt meters. you can see if it pays to oc or if it does not pay to oc. this was really true with gpu mining of BTC. I quickly learned that under clocking hd7970's saved far more watts and margin of profit was very tight when btc was 8-12 bucks a coin.
even no I under clock when I mine my lite coins. I also found out that antminers the u-1 usb's use almost no extra watts to jump from 1.6 gh to 2.0 gh after the 2.0 oc you kind of need to replace the resistors and pull more power.. but the soft ware oc from 1.6 to 2.0 a 25 percent hash rate over clock uses under 10% power jump.