I own 3 2-pacs and I'm having trouble getting them all to work at the same time. I have a Saberent HB-U14P usb hub. They all work fine individually, but when plugged into the hub, only 1 or 2 will work at the same time and the other turns zombie. Re-inserting means the other 2 will be disabled and only the re-inserted one will be hashing. Any tips?
Most consumer-grade USB hubs have voltage and current limiting built in. When you plug in more than one 2-Pac miner, it becomes the active one and zombies the others. To use more than one 2-Pac in the same hub requires closer attention to the hub's specs. I would say you need a hub that will output (permit) at least 1 amp per port. 2+ amps per port would be better if you want higher than stock hash rates.
the documentation for your hub states:
"For a stable connection, the devices connected to the 13 Port hub must not exceed a combined current of 5 volt 2.5A. Each USB port on our 13 Port hub will only provide 5 volts 300 Milliamps. "
You need more power.