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Unformatted text preview: with one hand--while you are grounded at the other side of your body-- will cause electrical current to pass across your chest, possibly injuring your heart and lungs. Currents across the chest are very dangerous. Page 8 Section 2 A male service technician arrived at a customer's house to perform pre-winter maintenance on an oil furnace. The customer then left the house and returned 90 minutes later. She noticed the service truck was still in the driveway. After 2 more hours, the customer entered the crawl space with a flashlight to look for the technician but could not see him. She then called the owner of the company, who came to the house. He searched the crawl space and found the technician on his stomach, leaning on his elbows in front of the furnace. The assistant county coroner was called and pronounced the technician dead at the scene. The victim had electrical burns on his scalp and right elbow. After the incident, an electrician inspected the site. A toggle switch that supposedly controlled electrical power to the furnace was in the "off" position. The electrician described the wiring as "haphazard and confusing." Two weeks later, the county electrical inspector performed another inspection. He discovered that incorrect wiring of the toggle switch allowed power to flow to the furnace even when the switch was in the "off" position. The owner of the company stated that the victim was a very thorough worker. Perhaps the victim performed more maintenance on the furnace than previous technicians, exposing himself to the electrical hazard. This death could have been prevented! The victim should have tested the circuit to make sure it was de-energized. Employers should provide workers with appropriate equipment and training. Using safety equipment should be a requirement of the job. In this case, a simple circuit tester may have saved the victim's life. Residential wiring should satisfy the National Electrical Code (NEC). Although the NEC is not retroactive, all homeowners should make sure their systems are safe. NEC--National Electrical Code-- a comprehensive listing of practices to protect workers and equipment from electrical hazards such as fire and electrocution Electrical burn on hand and arm. Section 2 Page 9 DA N G E r S O F E L E C T r I C A L S H O C K There have been cases where an arm or leg is severely burned by high-voltage electrical current to the point of coming off, and the victim is not electrocuted. In these cases, the current passes through only a part of the limb before it goes out of the body and into another conductor. Therefore, the current does not go through the chest area and may not cause death, even though the victim is severely disfigured. If the current does go through the chest, the person will almost surely be electrocuted. A large number of serious electrical injuries involve current passing from the hands to the feet. Such a path involves both the heart and lungs. This type of shock is often fatal. Arm with third degree burn from high-voltage line. Page 10 Section 2 Summary of Section 2
The danger from electrical shock depends on the amount of the shocking current through the body, the duration of the shocking current through the body, and the path of the shocking current through the body. Section 2 Page 11 B U r N S C AU S E D B Y E L E C T r I C I T Y Section 3 Burns Caused by Electricity Electrical shocks cause burns. arc-blast--explosive release of molten material from equipment caused by high-amperage arcs arcing--the luminous electrical discharge (bright, electrical sparking) through the air that occurs when high voltages exist across a gap between conductors The most common shock-related, nonfatal injury is a burn. Burns caused by electricity may be of three types: electrical burns, arc burns, and thermal contact burns. Electrical burns can result when a person touches electrical wiring or equipment that is used or maintained improperly. Typically, such burns occur on the hands. Electrical burns are one of the most serious injuries you can receive. They need to be given immediate attention. Additionally, clothing may catch fire and a thermal burn may result from the heat of the fire. Contact electrical burns. The knee on the left was energized, Arc Blasts and the knee on the right was grounded. Arc-blasts occur when powerful, high-amperage currents arc through the air. Arcing is the luminous electrical discharge that occurs when high voltages exist across a gap between conductors and current travels through the air. This situation is often caused by equipment failure due to abuse or fatigue. Temperatures as high as 35,000F have been reached in arc-blasts. A common example of arcing is the flash you sometimes see when you turn a light switch on or off. This is not dangerous because of the low voltage. There are three primary hazards associated with an arc-blast. (1) Arcing gives off thermal radiation (heat) and intense light, which can cause burns. Several factors affect the degree of i...
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- Spring '09