Wiring diagram of really safe using of knife. I know, that poor electrical contacors and designers in electrical companies have no money for long brian work (or maybe they have no brian) to design safe fuse boxes, so I realise these diagram under free license. Here knife fuse(s) is "F1", load switch is "LS1" and complex safety switch/door lock is "SS1". Auxilary circuits on the right side, containing low-voltage circuits to test circuits under safety low voltage.
<a href="//commons.wikimedia.org/wiki/User:Dmitry_G" title="User:Dmitry G">Dmitry G</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>