Hi as we always know the avoidance of shock and arc flash is a primary concene at all times in fact it's a part of he training that is very important I recently saw a guy on YouTube who calls himself electro boom who shows just what can happen if you don't isolate a circuit you want to work on I was thinking his videos mite be a good thing to show to students and apprentices and also think his survival so far is due to him being in 110 volt land ide hate to think how he'd get on in 220/240 volt country