Electrical Safety: Basic Principles
When working around electricity, maintaining personal safety requires knowledge and application of basic electrical safety principles, safe work practices and correct emergency response procedures. This program also provides definitions for several terms commonly used by electrical workers, housekeeping and circuit protection devices.
Shut Off the Power
ALWAYS shut off the breaker (or pull the fuse, in the case of an older house) that feeds the circuit you are about to work on. Most electrical distribution panels have a schedule on them as to which circuit is hooked up to which breaker. NEVER trust these, as they may be vague and non-descriptive, or changes may have been made and not documented.
ALWAYS verify that that the circuit is dead before working on it. You can do so by testing to make sure the power is off. Use a voltage tester or a lamp or radio. Plug the meter (lamp or radio) into the receptacle or plug that you are wanting to work on to verify that there is power. One by one, start turning off the breakers until you find the one that shuts off that particular circuit.
You may want to post a sign on the service panel to ensure that nobody attempts to restore power while you are working on the circuits. To really be sure, lock the panel. Always double-check the circuit with a voltage tester before you touch it. Don’t restore power until your repair or replacement has been completed.