It is a good idea to test the ckt. beforehand as well, to ensure that it is energized prior to turning it off. Then test to make sure it is off.This way you are more sure you have the right one. We also attempt to re-start any control circuits prior to testing with a tester that is verified on a known live ckt. Also, look for indications that another circuit is within the same enclosure, and either de-energize that also, or remember to stay clear. (This got me once.)
