Presentation on theme: "ELECTRICAL SAFETY AWARNESS TRAINING"— Presentation transcript:
1ELECTRICAL SAFETY AWARNESS TRAINING Training ProgramUpdated 5/5/04
2Electrical Fires in the USA Daily, fires occur due to electrical problems: defective electrical device, circuit overloading, circuit overheating, explosions ignited by electrical spark, etc.Electricity is one of the most common causes of fire in the USA. Each year there are approximately:1.6 million fires (all causes) reported,causing 3,600 fire deaths,18,000 fire related injuries,$10.7 billion in property damage.Source: National Fire Protection Association, 2007
3Grounding What is Grounding? “Grounding” a tool or electrical system means intentionally creating a low-resistance path that connects to the earth. This prevents the buildup of voltages that could cause an electrical accident.Grounding is normally a secondary protective measure toprotect against electric shock. It will substantially reduce therisk of injury or death in case of shock, especially when usedin combination with other electrical safety measures.An equipment ground helps protect the equipment operator.It furnishes a second path for the current to pass throughfrom the tool or machine to the ground. This additionalground safeguards the operator if a malfunction causes thetool’s metal frame to become energized. The resulting flowof current may activate the circuit protection devices.
4Protection Overcurrent Protection Fuses and circuit breakers open/break the circuit automatically when too much current flows through them.This is designed to protect the wiring/equipment from overheating and possible damage – NOT THE USERGFCI (Ground Fault Circuit Interrupter)Used in wet and other high-risk areas.Stops the flow of electricity when there isa difference between current leaving andreturning from the outlet.Should be tested monthlyPush test button and then the reset buttonThe basic idea of an over current (think of overcurrent as current out of control) protection device is to create a weak link in the system that will stop the flow of electricity before the overcurrent can cause any other damage.Overcurrent protection devices should always be placed on the hot leg and sized appropriately. Improper sizing can cause wiring or equipment to be damaged before the protection device has a chance to do its job.These devices may not and are not intended to protect people; they protect equipment.
5Power Extension Cords and Power Strips Extension Cords & Power Strips are for TEMPORARY use only!They may not be run through doorways, ceilings or windowsPower Strips (Transient Voltage Surge Suppressors)FOR ELECTRONICS ONLY (Computer Equipment etc.)NOT FOR APPLIANCES (Refrigerator, Microwave Toaster, Coffee Pot, Water Cooler etc.)Do not overloadThe number of outlets on the powerstrip does not indicate how manydevices can be connectedPower extension cords and power strips (also known as power taps) are a means to deliver electricity from a power source to a tool or device located where the power source is not.Sometimes the use of such power delivery devices presents overloading factors.The possible consequences of using a power strip should be considered beforehand.Some concerns includeDamaged or faulty devices posing fire and shock hazardsTripping hazardsRules to follow:Extension cords are authorized only for temporary use (to do the job at hand, not to remain as a power source for an extended amount of time (days, weeks).Extension cords may not be run through doorways, windows, ceilings, etc. whereby they may be damaged and/or pose tripping hazardExtension cords may not be smaller in diameter then the tool power cords to which they are connectedPower strips are authorized only for temporary use, if they are to be used as extension cordsPower strips designated as TVSS may be used for longer periods of time for electronic devices only (computers and components, adding machines, clocks, radios) but should not be overloaded or doubled-upPower strips and extension cords may not be used for appliances (refrigerators, microwaves, coffee pots, portable heaters)All devices and cords must be UL or comparably approved and in good working condition without any signs of damage12
6Properly Used Power Strip EXAMPLES OF A PROPERLYUSED POWER STRIPSTRIP IS NOT OVERLOADEDONLY COMPUTER (ELECTRICAL) EQUIPMENT IS ATTACHED TO STRIPCORDS ARE KEPT NEATNO EXTENSION CORDS ARE ATTACHED TO POWER STRIPPOWER STRIP IS ATTACHED DIRECTLY TO WALL OUTLET-NO EXTENSION CORD IS USED
7Improperly Used Power Strip EXAMPLES OF AN IMPROPERLYUSED POWER STRIPPOWER STRIP IS OVERLOADED DUE TO MINI-FRIDGE, MICROWAVE, AND TWO-POT COFFEE MAKER ALL ON ONE POWER STRIPAPPLIANCES ARE CONNECTED TO A POWER STRIP (THEY SHOULD BE CONNECTED DIRECTLY INTO A WALL OUTLET)POWER STRIP IS NOT CONNECTED DIRECTLY TO THE WALL OUTLET - AN EXTENSION CORD IS USEDEXTENSIONCORD IS USEDWITH POWERSTRIP
8Damaged and Unapproved Devices Not Permitted:Cord plug with ground prong missingDamaged TVSS rated power stripAdapter enables circuit overload
9Damaged and Unapproved Devices Not Permitted:Lamp extension cord, also damagedPower tapsAdapter to change 3-prong plugto 2-prong eliminating ground
10Container Bonding and Grounding (Static Electricity) Bonding CableGrounding CableGrounding Busor ElectrodeProper grounding and bonding is used to address the dangers of static electricity.In order for grounding to protect, all surfaces must be bonded together and grounded to earth.Static electricity is thereby released to earth as it is generated, preventing the accumulation of dangerous charges that may ignite flammable / hazardous substances.7
11ResponsibilitiesEntire system must be properly bonded and grounded to the earthFacilitiesResponsible for the system up to the wall outlet (all wiring and outlets)UserResponsible for the condition of plug and cord of equipmentInspect equipment to ensure plugs and cords are not damaged.Do not break off third prong or use adaptorsNo Prong = Not Grounded
12Electrical Safety Incidents The following is an example of :Electrocution Due to Improper Use of Common Equipment
13BackgroundDr. X was conducting an experiment related to plant growth. He needed to expose the plants to light for specific time-periods each day. Accordingly, he had a portable fluorescent lighting rack constructed and mounted on a wooden frame. He also obtained an electric timer to automatically turn the lights on and off. The light fixture was plugged into the timer, which was plugged into the wall outlet. However, since the timer only accepted a two prong plug, an adapter was used to allow the three prong plug of the lighting rack to be used with the two prong outlet of the timer.
14The IncidentDr. X adjusted the timer so that the lights would be on and plugged the timer into a standard 3-prong wall outlet. Then another person in the lab noticed Dr. X grasping the lighting rack and appearing to be rigid. A third person grasped Dr. X by the shoulders and pulled him away from the lighting rack. CPR was performed on him until EMS arrived. Dr. X was transported to a hospital where he was pronounced dead.
15The Investigation The investigation revealed the following details: A potential difference of 397 volts was measured between the metal fluorescent light fixture and the adjacent stainless steel sink. (There should not have been any potential difference). Both the fixture and the wall outlet were found to be wired correctly.The light fixture was rated for 800 mA, but the lamps used were 1500 mA.The transformer in the ballast was found to have short circuited to the case.
16What Probably Happened Use of bulbs drawing more current than approved for the fixture caused overheating of the ballast resulting in melting of insulation around the transformer coil. This allowed an energized transformer wire to touch the metal cover of the ballast which in turn energized the metal fluorescent fixture. The lights probably continued to function since they were wired correctly. When Dr. X grasped the fixture, some part of him probably brushed against the nearby metal sink. This completed a circuit to ground through Dr. X, electrocuting him.
17Preventing this Fatality As with many very serious accidents, a number of factors were involved, anyone of which could have prevented this fatality.If overrated lamps had not been used, the ballast would probably not have overheated and failed.If the ground wire connection between the light fixture and the plug not been interrupted by the "cheater" adapter and the two-prong timer, the fixture would have safely shorted to ground tripping the circuit breaker when the equipment was plugged in before Dr. X touched it.Had the standard outlet near the sink been Ground Fault Circuit Interrupter (GFCI) protected (as it should have been because it was near a sink), the GFCI would have tripped at the first flow of current through Dr. X immediately cutting off power to the fluorescent fixture and saving his life.These electrical safety violations cost Dr. X his life. If any one of them had beencorrected before the incident, Dr. X would still be researching plant growth.
18Don’t Let This Happen in Your Lab! 1)Follow manufacturer's recommendations for use of electricalequipment. Do not use electrical equipment for a task it is not designedfor.2) Generally, equipment used in research should have a 3 prong plug orbe double insulated. Equipment with neither of these features are lesssafe but may meet electrical codes. A 3 prong plug must always go intoa 3 prong outlet. Do not use a "cheater" plug or pull out the 3rd prong.3) Do not use multiple cube taps in a standard outlet. If you must plugmore than two pieces of low demand equipment into a standard outlet,use a fused power strip that will trip if too much power is used.4) Make sure that any outlet near a sink or other water source is GroundFault Circuit Interrupter (GFCI) protected. If you have a GFCI,periodically test it by plugging something into it and pushing the "test“button. The equipment should turn off and then turn it back on.
19…continued5) If you see a person being electrocuted, DO NOT TOUCH HIM! Theelectricity can go though you too. If possible, remove the power (pullplug or trip circuit breaker), or use a non-conductive item (e.g. woodenbroom handle) to pry him away from the contact.6) Above all, do not disable any electrical safety feature expecting thatanother safety feature will protect you. In the incident described above,if proper lamps were used, the ballast could still have been defectivefrom other causes. Also, GFCIs can be defective. That is why theyshould be periodically tested.7) Check that power cords are in good condition.8) Do not use extension cords as a substitute for permanent wiring.
20Electrical WorkElectrical work is only to be performed by qualified individualsContact Facilities X4588 for ALL electrical workDo not attempt to fix on your ownAttempting to repair equipmentyourself may create a hazardThis information is only provided to familiarize the reader with some basic concepts so he/she may better understand.EEW pertains to qualified electrical workers.They must attend additional and more extensive training than provided in this section.This does not apply to anyone attending the New Employee Orientation Training.13
21Conclusion Know and follow safe work rules and practices NO EXTENSION CORDS AS PERMANENT WIRINGPOWER STRIPS ARE FOR ELECTRONICS ONLYReport all unsafe conditions to Facilities X4588 or EHS X4078Do not take shortcuts and risk the safety of yourself or others.Know and follow safe work practices and procedures, and if you are unsure…ASK!!Use only appropriate tools and equipment for the work to be done.Inspect all tools and equipment prior to and during work activity.The label UL Approved only means the device left the factory meeting certain criteria.During the time that you may use the device, it may become damaged, therefore exposing yourself and others to hazards.Remember: stray electric current caused by damage to a device can shock, seriously injure or kill.Report any and all unsafe conditions:Receiving an electric shockSparksOverheating or smoking equipment;Corroded/damaged outlets, switches and junction boxes;Damaged extension cords and equipment power cords that are in use;Exposed wiring, broken plugs, outlets, missing box cover or faceplates;Outlets in damp areas not equipped with GFCI.Stay productive and safe - follow the rules.