I have a sub-panel (at left) with a 3-wire feed (H-H-N) from 100 amp breaker at bottom right of service panel, at right. The grounds and neutrals are Bonded at the sub-panel at ground/neutral bar behind all of the wiring at right of panel.
The two panels are bonded by metal conduit, as you can see between panels. When the panels are bonded can this be treated like one panel as far as keeping the grounded and grounding conductors bonded. Or does the “sub-panel” at left require isolating the neutral like any other sub-panel would, with the GEC’s bonded to panel?