>You are forbidden by law to have an accident? This misunderstanding is probably because of my lack of knowledge, but what do you mean? There are systems (perm

>You are forbidden by law to have an accident? This misunderstanding is probably because of my lack of knowledge, but what do you mean? There are systems (permits to work, lock out tag out, risk assessments, etc.) in place to maintain worker safety mandated by law. An incident of this kind typically means that there was a failure with one of more levels of the system... Someone did something they weren't supposed to, they turned off the wrong equipment, they didn't turn off the equipment before working on it, etc. > And trying to extinguish such an arc can be quite a challenge. Once established, an arc can continue as long as current is still flowing. It's possible for arcs to continue and still be below the trip current of the upstream circuit protection. In non-catastrophic scenarios, you have mechanisms to "quench" an arc... one method is to use compressed air.. like blowing out a very hot, angry candle on a birthday cake.