The power consumption number listed on the Antminer website for the S7 is as measured at the wall
You have to be real careful with this. That statement was true with the older 162 chip batches. The website read, "2. Power Consumption: 1160 W (at the wall, with APW3, 93% efficiency, 25C ambient temp)".
With the introduction of the 135 chip batches (batch 8 to current) Bitmain changed the statement to read, "2. Power Consumption: 1293W + 10% (at the wall, with APW3, 93% efficiency, 25C ambient temp)". This indicates that the S7 is actually around 1420 W at the wall with the most recent batches. It's a cheeky language shift by bitmain in an attempt to mask the loss of efficiency with 700Mhz setups.
Anyone running a batch 1-7 would be pushing this PSU to about 88% of rated performance. Not ideal in my personal opinion (I like to run PSUs around 80%), but certainly doable. And with industrial applications like mining who really cares if you run a few PSUs hard? Just bring ear plugs.
Throw a batch 8-17 on this guy though, and you're asking it to push about 108% of rated performance.
--Edit-- changed PSU performance on batch 1-7 from 92% (this is incorrect) to 88%.