As far as hot wires, we had an AntMiner on the test bench running on a 750w ATX PSU but had a cheesy molex to PCIe adapter that ended up putting all the load onto just 1 pair of about 18awg wire. When we noticed hot cables and the yellow turning brown, we moved to the correct set of cables (PSU is modular). Not only are the cables now running nice and cool, but it's also pulling 30watts less from the wall!!!
if you gave it another minute you wouldve seen a nice little blaze 
don't rely on ebay cables for mining rigs - they are not designed for large loads
#woopsAnd these weren't cheap ebay cables. They were the PSU's own modular adapter for the molex plugs, and then using a Gigabyte 280x's twin molex to PCIe 6pin. Lesson learned!