General Electrical Safety - American University of Beirut Safety... · This module addresses...
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Electrical Safety American University of Beirut Environmental Health, Safety & Risk Management ﺍﻟﺠﺎﻣﻌﺔ ﺍﻷﻣﻴﺮﻛﻴﺔ ﻓﻲ ﺑﻴﺮﻭﺕ ﺩﺍﺋﺮﺓ ﺍﻟﺼﺤﺔ ﺍﻟﺒﻴﺌﻴﺔ، ﺍﻟﺴﻼﻣﺔ ﻭﻣﻌﺎﻟﺠﺔ ﺍﻟﻤﺨﺎﻃﺮPrepared By: Bilal El-Iskandarani Senior Fire Protection Engineer EHS&RM, November 2013 1
General Electrical Safety - American University of Beirut Safety... · This module addresses OSHA’s General Industry electrical standards contained in 29 CFR 1910 Subpart S. OSHA
American University of Beirut Environmental Health, Safety & Risk Management
الجامعة األميركية في بيروت
الصحة البيئية، السالمة ومعالجة المخاطردائرة
Prepared By: Bilal El-Iskandarani Senior Fire Protection Engineer
EHS&RM, November 2013 1
Training Objectives Describe how electricity works Describe how shocks occur Describe how electrical current affects the body Learn about the most common electrical injuries Provide solutions to avoid electrical hazards
EHS&RM, November 2013 2
How Electricity Works
Example: A Garden Hose
Water Moves from High Pressure
To Low Pressure
The same thing occurs in an Electrical Wire
Current Moves from High Voltage
To Low Voltage
Flow of Current
EHS&RM, November 2013 3
Electrical Shocks
Note: Ground circuits provide a path for stray current to pass directly to the ground, and greatly reduce the amount of current passing through the body of a person in contact with a tool or machine that has an electrical short. Properly installed, the grounding conductor provides protection from electric shock.
Electricity travels in closed circuits, normally through a conductor Shock results when the body becomes part of the electrical circuit Current enters the body at one point and leaves at another Severity of the shock depends on:
Path of current through the body Amount of current flowing through the body Length of time the body is in the circuit
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How Electrical Current Affects the Body Current (Amps) Human Reaction
0.001 Perception level. Just a faint tingle.
0.005 Slight shock felt; not painful but disturbing. Average individual can let go.
0.006-0.025 (Women) Painful shock, muscular control is lost.
0.009-0.030 (Men) This is called the freezing current or "let-go" range.
0.050-0.150 Extreme pain, respiratory arrest, severe muscular contractions.
1 - 4.3 Ventricular fibrillation.
10 Cardiac arrest, severe burns and probable death.
Note: some smaller microwave ovens use 10.0 Amps (10,000 milliamps) and common florescent lights use 1 Amp (1,000 milliamps)
EHS&RM, November 2013 5
Currents greater than 75 mA* can cause ventricular fibrillation (rapid, ineffective heartbeat)
Will cause death in a few minutes unless a defibrillator is used
75 mA is not much current – a small power drill uses 30 times as much
Defibrillator in use
There are four main types of electrical injuries: Electrocution (death due to electrical shock) Electrical shock Burns Falls
Electrical Injuries
EHS&RM, August 2013 6
Presenter
Presentation Notes
This module addresses OSHA’s General Industry electrical standards contained in 29 CFR 1910 Subpart S. OSHA also has electrical standards for construction and maritime, but recommends that employers in these industries follow the general industry electrical standards whenever possible for hazards that are not addressed by their industry-specific standards. Suitability of electrical equipment for an identified purpose may be evidenced by listing or labeling by a nationally recognized testing laboratory which makes periodic inspections of equipment production and states that such equipment meets nationally recognized standards or tests to determine safe use in a specified manner. The Lockout/Tagout (LOTO) standard, 29 CFR 1910.147, is not covered in this presentation. However, you can find information on the Lockout-Tagout Interactive Training Program, under “OSHA Advisors” on the OSHA web site, www.osha.gov. Electricity is one of the most common causes of fire in homes and workplaces. Explosions have also resulted from electrical sources.
(The Most Common Form of Electrical Shock)
A ground-fault occurs when current flowing to the load (drill, saw, etc.) does not return by the prescribed route. In a simple 120 volt circuit, current travels through the black (ungrounded) wire to the load and returns to the source through the white (grounded) wire. If some or all of the current does not travel back through the white wire then it has gone somewhere else, usually to ground.
A person’s body can act as the path to ground when a fault occurs.
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Ground-Faults
Note: A GFCI will not protect you from line contact hazards (i.e. a person holding two "hot" wires, a hot and a neutral wire in each hand, or contacting an overhead power line). However, it protects against the most common form of electrical shock hazard, the ground-fault. It also protects against fires, overheating, and destruction of wire insulation.
The ground-fault circuit interrupter (GFCI) works by comparing the amount of current going to and returning from equipment along the circuit conductors. When the amount going differs from the amount returning by approximately 5 milliamperes, the GFCI interrupts the current within as little as 1/40 of a second.
The electrical cable of any used electrical equipment shall terminate with a plug.
Recommendations
EHS&RM, August 2013 9
Presenter
Presentation Notes
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
Use of electrical tape for electrical wire connections is prohibited. Electrical tape may be used to cover a junction or wire connectors.
Recommendations
EHS&RM, August 2013 10
Presenter
Presentation Notes
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
Do not remove ground pins/prongs from cord- and plug-connected equipment
Recommendations
EHS&RM, August 2013 12
Presenter
Presentation Notes
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
Protect live conductors.
Recommendations
EHS&RM, August 2013 13
Presenter
Presentation Notes
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
Discard any damaged electrical equipment that may have broken parts or frayed wires.
Recommendations
EHS&RM, August 2013 14
Presenter
Presentation Notes
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
Permanent use of extension cords is a violation of the Life Safety Code. They pose a tripping hazard, electrical hazard, and fire hazard. If you need additional permanent outlets, place a service request to have them installed.
Recommendations
EHS&RM, August 2013 15
Temporary (flexible wiring) must not be used in place of permanent wiring. Multioutlet surge protection such as this can be used to supply power to equipment that needs surge protection, but not used to provide more outlets due to the lack of permanent wiring.
Presenter
Presentation Notes
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
Place your desk so that the electrical outlets are located on one of its sides and not behind it. Otherwise place a service request to have new ones installed.
Recommendations
EHS&RM, August 2013 16
Presenter
Presentation Notes
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
DO NOT overload conductors , electrical outlets, or extension cords. Store item extension cords are not rated for or intended to simultaneously operate microwaves, kettles, refrigerators, heaters, etc… They are intended to provide power to items with light electrical consumption such as computers and telephones on a temporary basis only.
Recommendations
EHS&RM, August 2013 17
Presenter
Presentation Notes
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
Use of electrical adapters is not recommended. They tend to fail, generate sparks, and cause fires. If you have and equipment with a plug that is not compatible with the outlet you have in your office, place a service request to have a permanent compatible outlet installed.
Recommendations
EHS&RM, August 2013 18
Presenter
Presentation Notes
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
Remember
EHS&RM, August 2013 19
Remove cords from receptacles by pulling on the plugs, not the cords.
Electrical cables shall not pose obstructions or tripping hazards in egress passageways.
Protect flexible cords from damage.
Presenter
Presentation Notes
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
Keep your personal items away from electrical panel boards
Remember
EHS&RM, August 2013 20
Presenter
Presentation Notes
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
Water and electricity do not and shall not mix
Remember
EHS&RM, August 2013 21
Presenter
Presentation Notes
Reference 1926.404(b)(1)(i) GFCI: Matches the amount of current going to an electrical device against the amount of current returning from the device. Interrupts the electric power within as little as 1/40 of a second when the amount of current going differs from the amount returning by about 5 mA Must be tested to ensure it is working correctly. NEC requires GFCI’s be used in these high-risk situations: Electricity is used near water. The user of electrical equipment is grounded (by touching grounded material). Circuits are providing power to portable tools or outdoor receptacles. Temporary wiring or extension cords are used. There is one disadvantage to grounding: a break in the grounding system may occur without the user's knowledge. Using a ground-fault circuit interrupter (GFCI) is one way of overcoming grounding deficiencies.
Questions
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