Vex Cortex PTC divided on ports?

I am working with a student on dividing up current on the Cortex but cannot find which ports are on separate PTCs. I thought the first 5 were on one and the second are on 6 - 10. The student says he has seen something that said it was divided up on 3 internal PTCs.
Can you clarify this?

Hi Bill,

That is an excellent question!
The Cortex is evenly divided from 1-5 & 6-10.

If you want to add a third breaker, just purchase a Power Expander and connect it to ports 4, 5, 6 & 7.
Then you will have breakers on:

I hope this clarifies the situation.