Wire from bus to power supply

12 Gauge speaker wire?

No, speaker wire connects the 12G bus lines to the lock-on's on the track, roughly 12 places on each loop, to ensure consistent voltage around the loop as much as possible.  Not sure what gauge the speaker wire is, probably 14 or 16.

14 gauge should be fine, or 12 gauge as was suggested, if you have some handy. How long is the run from the feed ends of the bus wires to the PM? If more than say 15-20 ft then I would go with 12 gauge.

Rod

It's only about a foot from the bus to the powermasters.  I could connect them directly to the powermasters but bending 12G wire is a pain. I'd rather just tap into them with some stranded wire. I'll use 14G stranded.  Thanks!

Run a separate 14 gauge zip from each PM to the buss. That'll be just fine for a foot or 10 feet. About 25mv drop at 10 amps at 10 feet.