Unformatted text preview: ppropriate PPE must be used. PPE--personal protective equipment (eye protection, hard hat, special clothing, etc.) Section 5 Page 33 S A F E T Y M O D E L S TAG E 1 -- r E C O G N I Z I N G H A Z A r D S Low back pain can result from lifting objects the wrong way or carrying heavy loads of wire or other material. Back pain can also occur as a result of injury from poor working surfaces such as wet or slippery floors. Back pain is common, but it can be disabling and can affect young individuals. Chips and particles flying from tools can injure your eyes. Wear eye protection. Falling objects can hit you. Wear a hard hat. Sharp tools and power equipment can cause cuts and other injuries. If you receive a shock, you may react and be hurt by a tool. You can be injured or killed by falling from a ladder or scaffolding. If you receive a shock--even a mild one--you may lose your balance and fall. Even without being shocked, you could fall from a ladder or scaffolding. You expose yourself to hazards when you do not wear PPE. All of these situations need to be recognized as hazards. Lift with your legs, not your back! You need to be especially careful when working on scaffolding or ladders. Page 34 Section 5 Summary of Section 5 You need to be able to recognize that electrical shocks, fires, or falls result from these hazards: Inadequate wiring Exposed electrical parts Overhead powerlines Defective insulation Improper grounding Overloaded circuits Wet conditions Damaged tools and equipment Improper PPE Section 5 Page 35 S A F E T Y M O D E L S TAG E 2 -- E VA L UAT I N G H A Z A r D S Section 6 Safety Model Stage 2-- Evaluating Hazards
How Do You Evaluate Your risk? risk--the chance that injury or death will occur Make the right decisions. After you recognize a hazard, your next step is to evaluate your risk from the hazard. Obviously, exposed wires should be recognized as a hazard. If the exposed wires are 15 feet off the ground, your risk is low. However, if you are going to be working on a roof near those same wires, your risk is high. The risk of shock is greater if you will be carrying metal conduit that could touch the exposed wires. You must constantly evaluate your risk. Combinations of hazards increase your risk. Improper grounding and a damaged tool greatly increase your risk. Wet conditions combined with other hazards also increase your risk. You will need to make decisions about the nature of hazards in order to evaluate your risk and do the right thing to remain safe. There are "clues" that electrical hazards exist. For example, if a GFCI keeps tripping while you are using a power tool, there is a problem. Don't keep resetting the GFCI and continue to work. You must evaluate the "clue" and decide what action should be taken to control the hazard. There are a number of other conditions that indicate a hazard. Tripped circuit breakers and blown fuses show that too much current is flowing in a circuit or that a fault exists. This condition could be due to several factors, such as malfunctioning equipment or a short between conductors. You need to determine the cause in order to control the hazard. An electrical tool, appliance, wire, or connection that feels warm may indicate too much current in the circuit or equipment or that a fault exists. You need to evaluate the situation and determine your risk. An extension cord that feels warm may indicate too much current for the wire size of the cord or that a fault exists. You must decide what action needs to be taken. Combinations of hazards increase risk. short--a low-resistance path between a live wire and the ground, or between wires at different voltages (called a fault if the current is unintended) Page 36 Section 6 A cable, fuse box, or junction box that feels warm may indicate too much current in the circuits. A burning odor may indicate overheated insulation. Worn, frayed, or damaged insulation around any wire or other conductor is an electrical hazard because the conductors could be exposed. Contact with an exposed wire could cause a shock. Damaged insulation could cause a short, leading to arcing or a fire. Inspect all insulation for scrapes and breaks. You need to evaluate the seriousness of any damage you find and decide how to deal with the hazard. A GFCI that trips indicates there is current leakage from the circuit. First, you must decide the probable cause of the leakage by recognizing any contributing hazards. Then, you must decide what action needs to be taken. Any of these conditions, or "clues," tells you something important: there is a risk of fire and electrical shock. The equipment or tools involved must be taken out of service. You will frequently be caught in situations where you need to decide if these clues are present. A maintenance electrician, supervisor, or instructor needs to be called if there are signs of overload and you are not sure of the degree of risk. Ask for help whenever you are not sure what to do. By ask...
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This document was uploaded on 03/14/2014 for the course ECE 482 at University of Tennessee.
- Spring '09