If you're installing chandelier in living home, you may turn circuit breaker off and attach letter, that you're working and circuit breaker must stay in "OFF" position till you work.

But how to be in factory, if you're working with powerful electric motor? If someone turn circuit breaker on, spining motor can injure you, sometimes even kill you or other personal. Let's see how to do it correctly:

• 1) Turn power off
• 2) Seal interrupter by the lock
• 3) Check your voltmeter and only then check voltage between hot wires and each hot wire to ground. After it, check by voltmeter, that you've disenergized correct circuit.
• 4) If you've turned power off from correct circuit, you should switch hot wires from interrupter to earthing busbar. After hot wires are installed to earthing busbar, you can start your work.