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Unformatted text preview: one of the lights. Needle-nose wire strippers were stuck in the left side of the victim's chest. Apparently, he had been stripping insulation from an improperly grounded 530-volt, single-strand wire when he contacted it with the stripper. In this case, the electricians knew they were working on energized circuits. The breakers in the booth's control panel were not labeled and the lock used for lock-out/tag-out was broken. The surviving electrician stated that locating the means to de-energize a circuit often takes more time than the actual job. The electrician would be alive today if the following rules had been observed. Always shut off circuits--then test to confirm that they are de-energized--before starting a job. Switchgear that shuts off a circuit must be clearly labeled and easy to access. Lock-out/tag-out materials must always be provided, and lock-out/tag-out procedures must always be followed. Always label circuit breakers. Lock out and tag out circuits and equipment
Create a safe work environment by locking out and tagging out circuits and machines. Before working on a circuit, you must turn off the power supply. Once the circuit has been shut off and de-energized, lock out the switchgear to the circuit so the power cannot be turned back on inadvertently. Then, tag out the circuit with an easy-to-see sign or label that lets everyone know that you are working on the circuit. If you are working on or near machinery, you must lock out and tag out the machinery to prevent startup. Before you begin work, you must test the circuit to make sure it is de-energized. Always test a circuit to make sure it is de-energized before working on it. Section 7 Lock-out/tag-out saves lives. Page 39 S AF ET Y M O D EL S TAG E 3--C O N T rOLLING HAZArDS: SAFE WOrK ENVIrON M EN T Lock-Out/Tag-Out Checklist
Lock-out/tag-out is an essential safety procedure that protects workers from injury while working on or near electrical circuits and equipment. Lock-out 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 then tagged out with an easy-to-read tag that alerts other workers in the area that a lock has been applied. I n addition to protecting workers from electrical hazards, lock-out/tag-out prevents contact with operating equipment parts: blades, gears, shafts, presses, etc.
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. When performing lock-out/tag-out on machinery, you must always lock out and tag out ALL energy sources leading to the machinery. Also, lock-out/tag-out prevents the unexpected release of hazardous gases, fluids, or solid matter in areas where workers are present.
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. When performing lock-out/tag-out on circuits and equipment, you can use the checklist below. Identify all sources of electrical energy for the equipment or circuits in question. Disable backup energy sources such as generators and batteries. Identify all shut-offs for each energy source. Notify all personnel that equipment and circuitry must be shut off, locked out, and tagged out. (Simply turning a switch off is NOT enough.) Shut off energy sources and lock switchgear in the OFF position. Each worker should apply his or her individual lock. Do not give your key to anyone. Test equipment and circuitry to make sure they are de-energized. This must be done by a qualified person.* Deplete stored energy (for example, in capacitors) by bleeding, blocking, grounding, etc. Apply a tag to alert other workers that an energy source or piece of equipment has been locked out. Make sure everyone is safe and accounted for before equipment and circuits are unlocked and turned back on. Note that only a qualified person may determine when it is safe to re-energize circuits. *OSHA defines a "qualified person" as someone who has received mandated training on the hazards and on the construction and operation of equipment involved in a task. Page 40 Section 7 Control inadequate wiring hazards
Electrical hazards result from using the wrong size or type of wire. You must control such hazards to create a safe work environment. You must choose the right size wire for the amount of current expected in a circuit. The wire must be able to handle the current safely. The wire's insulation mus...
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- Spring '09