Electrical Safety IV

Verification of De-energized State 

Before any electrical equipment can be worked on as de-energized, a qualified individual must open the equipment disconnect, operate the start/stop controls, and/or otherwise verify that the equipment cannot be reenergized. In addition, the qualified individual should use appropriate testing equipment to verify that the exposed equipment or circuit is de-energized. If the circuit is 110 volts, or greater, the test equipment must be checked for proper operation both before and after use.

1. The equipment or circuit to be worked on must be disconnected from all electrical energy sources. Control circuit devices such as push buttons, selector switches, and interlocks may not be used as the only means for de-energizing equipment or circuits.
2.  All stored electrical energy sources that may endanger personnel must be released. Capacitors must be discharged and high capacitance items must be short-circuited and grounded if an electrical hazard exists
3. Stored non-electrical energy that might re-energize electrical circuit parts must be blocked or relieved to eliminate the potential for this to occur
4. A lock and tag must be placed on each disconnecting means used to de-energize circuits and equipment, by each authorized employee.