Electrical resistances were about twice what is allowed for that grade of wire. And every single breaker failed to trip when tested.
Unless I've missed something, it was 5 out of 421 breakers that failed. And those were mostly ones that were exposed to poor environments, like being in outdoor mounted boxes and such, and had insect intrusions and corrosion.
The old BX cable that has twice the permitted resistance in its armor is a bit worrisome. My mom's house has some runs of BX without the bonding strip, but they are short enough to keep the total resistance low enough to trip the breaker if a fault happens (we have subpanels in the center hallways of the house, so home runs are fairly short). The brittle insulation is another problem, but my father used top quality outlets and switches so we rarely have to mess with them.
