Backfed + Sub panel

2 questions : I have seen this before on the forum but this is my first time i have come across this and want to make sure I understand this correctly.
Top panel is backfed with 100 amp main breaker, top lugs are then going to Sub panel below providing power.
1-The OCPD for the sub panel is the Main breaker I assume ?
2-The bond strap is connected in ‘sub panel’ - which is No good, unless this should not be wired as a sub panel since the power is provided from the main panel lugs and is not a sub panel ??

The back fed breaker needs a listed device or screw to hold it in place.

The sub panel has no OCPD

All panels down stream of the service disconnect are sub panels and the neutrals should not be bonded to the panel. There’s an exception, but it’s for detached structures.

Plus you have mismatched breakers and a 240v circuit or MWBC that’s missing a handle tie.

Looks like a mess

Thanks for clarifying the sub panel , I noticed no screw holding it down - I assume it would need a different method to retain it, rarely see them have anything holding them in place, you would think they changed the installment need for them.

I thought they were the screws also but when i inspected it , those holes had rivets in them. I assume that is what’s holding the double breaker together as one and not securing it to the panel. But i am open for opinions on it .

MWBC on a tandem sharing the same neutral also. Yeah a few issues, just a few :mrgreen:

I was wondering. I will leave it to you a Juan he has you on the right track.

MWBC’s always share a neutral.

Yes, but these are on the same tandem , therefor on the same phase. Need to be on different phases so they dont overload the neutral.

Each tandem breaker provides 2 - 120 V circuits, that fits the space of 1 regular 120v breaker. Both tandem terminals are both powered from the same leg, and can not share the same neutral wire.

Looks to me like the 100 amp back-fed CB has two screws or rivets holding it in place, dead center on both ends.

Yes it was rivets, wasnt sure if rivets hold it in place or are part of the breaker itself. Are rivets installed by electrician or does the panel come that way from mfg?