For accidents to occur, hazardous conditions and unsafe behaviors must somehow interact. A safe work environment is not enough to control all electrical hazards. You must also work safely. Safe work practices help you control your risk of injury or death from workplace hazards. If you are working on electrical circuits or with electrical tools and equipment, you need to use safe work practices.
Before you begin a task, ask yourself:
All workers should be very familiar with the safety procedures for their jobs. You must know how to use specific controls that help keep you safe. You must also use common sense good sense.
Note: So, why did we strike through "common sense" above? That's because there's no such thing as common sense! We harp on this all the time. You've got to use good sense, and in order to do that, you need to be educated, trained, and experience. There is no way to get around it. Do not assume anyone has common sense: That will get you in trouble and possibly hurt.
Control electrical hazards through safe work practices.
1. For accidents to occur _____ must interact with _____.
a. unsafe actions, existing conditionsTake time to plan your work, by yourself and with others. Safety planning is an important part of any task. It takes effort to recognize, evaluate, and control hazards. If you are thinking about your work tasks or about what others think of you, it is hard to take the time to plan for safety. But, YOU MUST PLAN.
Planning with others is especially helpful. It allows you to coordinate your work and take advantage of what others know about identifying and controlling hazards. The following is a list of some things to think about as you plan.
2. When working on electrical circuits, even low-voltage circuits, the circuits must be _____.
a. de-energizedA worker was attempting to correct an electrical problem involving two non-operational lamps. He examined the circuit in the area where he thought the problem was located.
He had not shut off the power at the circuit breaker panel and did not test the wires to see if they were live. He was electrocuted when he grabbed the two live wires with his left hand.
He collapsed to the floor and was found dead.
The fatality in this accident would not have occurred if the following safe work practices had been followed:
3. Unless you are authorized to work on energized circuits, you must do each of the following prior to working on electrical circuits EXCEPT _____.
a. shut off the circuitBe very careful not to contact overhead powerlines or other exposed wires. More than half of all electrocutions are caused by contact with overhead lines. When working in an elevated position near overhead lines, avoid locations where you (and any conductive object you hold) could contact an unguarded or uninsulated line. You should be at least 10 feet (3.05 meters) away from high-voltage transmission lines.
Vehicle operators should also pay attention to overhead wiring. Dump trucks, front-end loaders, and cranes can lift and make contact with overhead lines. If you contact equipment that is touching live wires, you will be shocked and may be killed. If you are in the vehicle, stay inside. Always be aware of what is going on around you.
Underground powerlines present a different set of hazards. Workers digging with heavy equipment or using power tools are injured most frequently by inadvertent exposure to live underground powerlines.
Be sure that you call the local utility company to submit a "locate request" before digging. The federally-regulated "call before you dig" number is 811. Locate crews will mark your dig site within a few days so that you know where to avoid digging. Always dig around the marks/flags, not on them.
4. When performing hoisting operations, keep at least _____ away from high-voltage transmission lines.
a. 3 feetUse the following best practices when working with wiring and connectors:
Check switches and insulation - Tools and other equipment must operate properly. Make sure that switches and insulating parts are in good condition.
Use three-prong plugs - Never use a three-prong grounding plug with the third prong broken-off. When using tools that require a third-wire ground, use only three-wire extension cords with three-prong grounding plugs and three-hole electrical out-lets. Never remove the grounding prong from a plug! You could be shocked or expose someone else to a hazard. If you see a cord without a grounding prong in the plug, remove the cord from service immediately.
Use extension cords properly - If an extension cord must be used, choose one with sufficient ampacity for the tool being used. An undersized cord can overheat and cause a drop in voltage and tool power. Check the tool manufacturer's recommendations for the required wire gauge and cord length. Make sure the insulation is intact. To reduce the risk of damage to a cord's insulation, use cords with insulation marked "S" (hard service) rather than cords marked "SJ" (junior hard service). Make sure the grounding prong is intact. In damp locations, make sure wires and connectors are waterproof and approved for such locations. Do not create a tripping hazard.
5. What should you do if you see an extension cord with the ground prong missing?
a. Connect it only to two-prong outletsUse the following best practices when working with wiring and connectors:
6. Which of the following is a safe work practice when using electrical wiring and connectors?
a. Inspect the cord while energized to ensure continuityHand and power tools are a common part of our everyday lives and are present in nearly every industry. These tools help us to easily perform tasks that otherwise would be difficult or impossible. However, these simple tools can be hazardous and have the potential for causing severe injuries when used or maintained improperly. Special attention toward hand and power tool safety is necessary in order to reduce or eliminate these hazards.
Your tools are at the heart of your craft. Tools help you do your job with a high degree of quality. Tools can do something else, too. They can cause injury or even death! You must use the right tools for the job. Proper maintenance of tools and other equipment is very important. Inadequate maintenance can cause equipment to deteriorate, creating dangerous conditions. You must take care of your tools so they can help you and not hurt you.
Note: DO NOT USE THESE TOOLS TO WORK ON ENERGIZED CIRCUITS. ALWAYS SHUT OFF AND DE-ENERGIZE CIRCUITS BEFORE BEGINNING WORK ON THEM.
Read more about and power tool safety
7. When used properly, double-insulated tools provide reliable shock protection without the need for a _____.
a. third ground wireAn open neutral is the most dangerous and unknown hazard a worker can encounter when it's line is not de-energized. It’s important to understand that in a 3-phase electrical system, all three phases must be verified as de-energized or there may be the potential for a shock. The neutral circuit wire (usually white) is grounded, but is under a load and the source of the neutral current cannot always be identified.
If a grounded (neutral) service conductor which serves as the effective ground-fault current path is opened, a ground fault cannot be cleared and the metal parts of electrical equipment, as well as metal piping and structure steel will become and remain energized providing the potential for electric shock.
Potential hazards include:
For instance, in 2005 a worker received a shock after lifting a neutral from its bus bar. The neutral received its power through an emergency light that received power from another distribution panel.
An employee was climbing a metal ladder to hand an electric drill to the journeyman installer on a scaffold about 5 feet above him. When the victim reached the third rung of the ladder, he received an electrical shock that killed him. An investigation showed that the grounding prong was missing from the extension cord attached to the drill. Also, the cord's green grounding wire was, at time, contacting the length of the grounding wire and the drill's frame became energized. The drill was not double-insulated.
To avoid deadly incidents like this one, take these precautions:
8. If you see a loose white wire on an energized circuit, what does it mean?
a. A possible short circuit of the hot wire: possible problemOSHA requires that you be provided with personal protective equipment. This equipment must meet OSHA requirements and be appropriate for the parts of the body that need protection and the work performed. There are many types of PPE: rubber gloves, insulating shoes and boots, face shields, safety glasses, hard hats, etc. Even if laws did not exist requiring the use of PPE, there would still be every reason to use this equipment. PPE helps keep you safe. It is the last line of defense between you and the hazard.
9. Which of the following is considered electrical protective equipment?
a. R23 hearing protectionRead the material in each section to find the correct answer to each quiz question. After answering all the questions, click on the "Check Quiz Answers" button to grade your quiz and see your score. You will receive a message if you forgot to answer one of the questions. After clicking the button, the questions you missed will be listed below. You can correct any missed questions and check your answers again.