This panel, a Cutler Hammer, has a 4/0 alum. feed from an SEU cable in the top. There are several 2pole brkrs. in the top 1/3 of the panel. and there is a 60amp breaker on the left side one up from the bottom. there is a pair of wires (#4 copper)that connect the the breaker to the bottom of the buss bar. I can determine from that this panel has a split buss. The 60a kills the bottom of the panel only. The top portion, doesn’t appear to have a disconnect, but is bonded, and water pipe grounded.