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Module 4. Methods of Control. Control. Recognize. Evaluate. Module Objectives. Identify the three types of control that should be used to achieve electrical safety. Identify the engineering, administrative and PPE controls you use on your job.
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Module 4 Methods of Control
Control Recognize Evaluate
Module Objectives • Identify the three types of control that should be used to achieve electrical safety. • Identify the engineering, administrative and PPE controls you use on your job. • Identify facts and procedures relating to lockout/tagout.
Module Objectives • List the steps required to achieve an electrically safe condition. • Recognize when a work permit is required to work on energized electrical circuits. • Recognize the appropriate warning signs to alert employees to the danger of electricity.
Module Objectives • Recognize the appropriate PPE to use based on the calculated energy value of an energy source. • Given a case study, determine the most appropriate method of control and necessary corrective action.
What is a Control? A control is a measure or an action that is taken to eliminate current hazards and to prevent future hazards.
Three Types of Control Engineering PPE Administrative
Engineering Controls Controls that are engineered into the job. The focus is on eliminating the hazard altogether.
Engineering Control Examples • Redesign of equipment • Substitution of material, equipment or process • Change process to eliminate exposure • Use of barriers to isolate the hazard • Use of barriers or shields to isolate the worker
Safe Wiring • Choose the correct size of wire for the amount of current in the circuit. • Make certain that the wire’s insulation is appropriate for the voltage. • Make sure the wire is tough enough for the conditions. • Make sure the connection is reliable. • Make sure the connections are protected.
Administrative Controls Controls that reduce employee exposures through administrative methods. Depend on constant implementation or intervention.
Administrative Control Examples • Education and training • Procedures to limit exposure • Maintenance • Good housekeeping • Signs and warnings • Distance
Personal Protective Equipment (PPE) Controls that are worn by employees to protect them from the environment.
PPE Examples • Protective Clothing • Protective Gear Photo courtesy of Schneider Electric
Arc Blast Controls • Engineering • Administrative • PPE Photo courtesy of Schneider Electric
Comparison of Blasts Both Blasts: 480 Volts, 30,000 Amps Uncontrolled Blast Circuit Breaker Blast • Circuit opened in 330 milliseconds • Incident energy = 30 calories per cm2 • Circuit opened in 8 milliseconds • Incident energy = .30 calories per cm2 Circuit breaker = energy reduction factor of 100!
What is Lockout/Tagout? Photo courtesy of Schneider Electric
Lockout The placement of a lockout device on an energy isolating device, in accordance with an established procedure, ensuring that the energy isolating device and the equipment being controlled cannot be operated until the lockout device is removed.
DANGER Tagout The placement of a tagout device on an energy isolating device, in accordance with an established procedure, to indicate that the energy isolating device and the equipment being controlled may not be operated until the tagout device is removed.
1910.147 Versus 1910.333 1910.147 1910.333 When • Equipment that might unexpectedly energize • Energized circuits Who • Authorized person • Qualified person Verifi-cation • Verifies isolation and de-energization • Tests for energized condition due to inadvertant voltage or voltage backfeed
Warnings and Signs Illustrates minimum requirement. This is an example, not a recommendation. Slide courtesy of Schneider Electric
Warnings and Signs Slide courtesy of Schneider Electric
Selecting PPE Output Category Incident Energy (Cal/cm2) PPE 0 1 2 3 4 N/A 4 8 25 40 • Untreated cotton • FR shirt and FR pants • Cotton underwear plus FR shirt & FR pants • Cotton underwear plus FR shirt & FR pants plus FR coverall • Cotton underwear plus FR shirt & FR pants plus double layer switching coat and pants S a m p l e O n l y
PPE—Hand and Arm Protection Photo courtesy of Schneider Electric
PPE—Face, Hands, Arms, Torso Photo courtesy of Schneider Electric
PPE—Face, Hands, Arms, Torso Photo courtesy of Schneider Electric
Electrical Controls—Case 2 Photo Source: NIOSH Safety and Health for Electrical Trades
Electrical Controls—Case 3 Photo Source: NIOSH FACE Case 03NE022
Electrical Controls—Case 4 Photo Source: NIOSH FACE Case 03NE022