How to turn off an energized system

This process is often confused. Its better concept is: a set of steps to eliminate any electric risks envolved in the turning off process.

Only switching the breaker doesn't guarantee a safe condition to work. Following these steps, you'll guarantee more safety for your services (here in Brazil there's a norm that says you have to follow these steps):

1. Switching the breaker.
2. Hinder the act of switching on the system, using a lock (its key only the worker has).
3. Verify presence of voltage (because nobody guaratees that the breaker relly broke the circuit).
4. Make the terminals have the same potencial (by jumping them), after the breaker. This step guarantees that there's no voltage between the terminals.
5. Grounding the chassis and the terminals.
6. Protection from energized equipaments in controlled area, to avoid accidentally touches. The worker must have to worry about his own work, and nothing else.
7. Finally, try to spread signs for warning the others that there're men working.

But nor always we have to follow the steps above, for example: we have a breaker inside a box (with a proper door). If its possible, we can equipotencialize all terminals and the ground, before lock the switcher.

In addition of this, there're some areas that require adaptations in the procedure (some special dangers). But the new procedure must be safer than the default.

The idea is to use the good-sense.

For turning on the circuit again, follow these steps:

1. Collect all the instruments and materials used during the service.
2. Instruct everybody to the process of turning on.
3. Remove grounding and jumps (include extra protections).
4. Remove warnings (note that this is almost the last step).
5. Remove locks and the authorization is given.

Following all of these steps (all of them is written in NR-10 (Brazil)), you'll guarantee safer conditions for you and your staff, reducing risks of electric shocks (and all its results).