Safety first... and second, and probably third

my injured lineman's tool

So I was working in the garage installing new lights. I had verified the circuit breaker responsible for powering the circuit I would be wiring the new lights into, no problems here. Before I got around to installing the lights I realized I had other work to take care of first. So I turned the breaker back on as it was also powering outlets I needed, no problems here either.

After I was done with the sidetracking work I turned the breaker back off in preparation for wiring the lights up, no problems here either. Using my lineman's tool I then cut the Romex line I would be reworking to run my new lights... problems.

Immediately I had lights, not of the useful overhead lighting kind, along with the popping and hissing noises which accompany shorting a live wire. I was also working on a ladder, which in this case functioned as an unnecessary excitement multiplier, which I ungracefully abandoned. The wire was roasted and my tool now had a notch of metal blasted out by the short circuit arc.

closeup showing missing metal

But the circuit breaker was off. Why was there still power?

Simple. I had turned off the wrong circuit breaker. The breaker I shut off did not have any visual manifestations which would indicate I had gotten the wrong one. So I proceeded with my work. The error was not verifying the power was off at the place and time of the work. Had I checked the line right before starting work again (I had several tools which would do this for me) I would have caught the problem.

Instead I am down one pair of pliers. A small price considering other possible outcomes.