I am working on finishing my basement. In my basement there is 3 junction boxes fed by 12/3 wire. Each junction box feeds a single 12/2 line (White-White, Black-Black, Ground-Ground, Red-Nothing). My thought was this was done to allow expansion at a later date and my plan was to use the unused used red line.
I opened up the circuit breaker to see how they were wired (See picture). From my understanding of a MWBC each breaker should be on a different bus so that the load on the neutral would be the difference. If I'm looking at this right these are all wired wrong with both the black and red lines on the same bus bar.
In the picture:
Junction Box 1 - Breaker 1 + 5
Junction Box 2 - Breaker 2 + 6
Junction Box 3 - Breaker 4 + 8
If this is indeed incorrect, slightly more concerning is that 3 + 7 are on a 3-wire and both in use.