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715 Electrical Safety for Technicians and Supervisors
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Lockout and Tagout Circuits and Equipment

Lockout/tagout is an essential safety procedure that protects workers from injury from the unexpected startup or shutdown of equipment or machinery during servicing and maintenance.

Lockout/Tagout protects against unexpected startup or shutdown.

Lockout involves applying a physical lock to the power source(s) of circuits and equipment after they have been shut off and de-energized. The source is locked out with a lock and easy-to-read tag that alerts other workers in the area that a lock has been applied.

In addition to protecting workers from electrical hazards, lockout/tagout prevents contact with operating equipment parts: blades, gears, shafts, presses, etc. Read more about Lockout/Tagout by taking OSHAcademy course 710 Energy Control Program (Lockout/Tagout).

Case Studies

A worker was replacing a V-belt on a dust collector blower. Before beginning work, he shut down the unit at the local switch. However, an operator in the control room restarted the unit using a remote switch. The worker's hand was caught between the pulley and belts of the blower, resulting in cuts and a fractured finger.

Remember, when performing lockout/tagout on machinery, you must always lockout and tagout ALL energy sources to the machinery.

An employee was cutting into a metal pipe using a blowtorch. Diesel fuel was mistakenly discharged into the line and was ignited by his torch. The worker burned to death at the scene

All valves along the line should have been locked out, blanked out, and tagged out to prevent the release of fuel. Blanking is the process of inserting a metal disk into the space between two pipe flanges. The disk, or blank, is then bolted in place to prevent passage of liquids or gases through the pipe.

Lockout/tagout prevents the unexpected release of hazardous gases, fluids, or solid matter in areas where workers are present.

Knowledge Check Choose the best answer for the question.

7-3. Which procedure can protect workers against injury due to the unexpected equipment and machinery startup or shutdown?