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[Sample USC Safety Program] August 26, 2010

ELECTRICAL SAFETY PROGRAM

1.0 INTRODUCTION

Nationwide more than 1,000 individuals are killed and another 30,000 injured each year from electrical shock. University of South Carolina employees work with and around electrical equipment every day. Therefore, University of South Carolina has developed the following electrical safety program to comply with National Fire Protection Association (NFPA 70E 2009 Edition and CFR 1910 Subpart S-Electrical.

2.0 PURPOSE

The purpose of the Electrical Safety Program is to help employees have a better understanding of how to safely work with and around electrical equipment.

3.0 LOCKOUT/TAGOUT/TRY PROGRAM

University of South Carolina requires that all equipment and systems be de-energized Lockout/Tagout/Tried prior to performing any type of work on the equipment. The only two exceptions to this program are when continuity of service is required such as when troubleshooting and diagnostic testing.

Important Note: When working on energized electrical conductors or circuit parts that are not placed in an electrical safe condition “Lockout/Tagout/Tried” (i.e., for the reasons of increased or additional hazards or infeasibility per NFPA 70-E 130.1), work to be performed shall be considered energized electrical work and shall not be perform without a completed written permit. See Appendix A (USC Energized Electrical Work Permit)

4.0 RESPONSIBILITIES

4.1 Managers and Supervisor

1. Verifies that all employees are trained to the requirements of the Electrical Safety Program2. Budgets sufficient funds to execute the Electrical Safety Program3. Participates in the electrical safety training program.4. Verifies that all contractors and subcontractors are following the program requirements.

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4.2 Team leaders

1. Enforces the requirements of the Electrical Safety Program2. Ensures that employees doing electrical work are properly trained.3. Secures equipment/PPE necessary to perform electrical work safely.

4.3 Employees

1. Participate in training sessions.2. Use proper equipment when doing electrical work.3. Notify supervisor if any electrical equipment appears unsafe.4. Review and adhere to all Electrical Work requirements set forth in this program.

4.4 Contractors and Subcontractors

Adhere to the requirements of this program.

5.0 TERMS

5.1 Alternating current (AC) – a flow of electrons which regularly reverses its direction of flow.

5.2 Ammeter – an instrument used for measuring current.

5.3 Ampacity – the current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.

5.4 Ampere (A) – the basic unit of measurement for current.

5.5 Arc - is an electrical discharge generated when two energized conductors are separated, causing a buildup of heat and gas to cross the gap.

5.6 Arc Flash Protection – the maximum incident energy resistance demonstrated by a material (or a layered system of materials) prior to degradation or at the onset of a second-degree skin burn. Arc rating is normally expressed in cal/cm2.5.7 Battery – a DC electrical power source composed of two or more chemical cells.

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5.8 Blast – pressure that is generated by an arc can result in an explosion or blast.

5.9 Burns – there are four types of burns:a. First degree - this is a minor burn to the Epidermis layer of the skin and is usually superficial. The appearance is red with no blisters. It usually takes three to six days to heal.b. Second degree - this is a burn that causes damage to the Epidermis layer of the skin and the Dermis. All types of second degree burns are listed as moderate burns.c. Third degree - this is a critical burn that causes a destruction of all the Epidermis and Dermis. It goes to the root of the hair follicle. A third degree burn is called a Full Thickness Burn. It is usually darkbrown and has a leathery appearance. Skin grafting is recommended.d. Fourth degree - the tissue beneath the skin is burned/destroyed. That includes the muscles, tendons, ligaments and bones. Skin grafting is usually needed to close up the areas.

5.10 Capacitor – an electric circuit element used to temporarily store an electric charge, consisting of two conductors separated by an insulator or dielectric. Designed to provide a specific amount of storage.

5.11 Circuit – an electrical path having a power source, load and conductors to carry current.

5.12 Circuit breaker – a device designed to open and close a circuit by nonautomatic means and to open the circuit automatically on a predetermined overcurrent without damage to itself when properly applied within its rating.

5.13 Conductive – suitable for carrying electric current.

5.14 Conductor - is a material that allows free motion of a large number of electrons. It has low resistance to current flow. Aluminum, steel, copper, water and the human body are all good conductors.

5.15 Conductor, bare – a conductor having no covering or electrical insulation.

5.16 Conduit – specially built tubing to hold wire and protect it from damage.

5.17 Current – the flow of electrons through a conductor, measured in amperes.

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5.18 Dead front – without live parts exposed to a person on the operating side of the equipment.

5.19 Deenergized – free from any electrical connection to a source of potential difference and from electrical charge.

5.20 Direct current (DC) – a source of electrical energy where the polarity does not change and current always flows in the same direction.

5.21 Disconnect – breaks the power to an electrical circuit.

5.22 Electrically safe work condition – a state in which the conductor or circuit part to be worked on or near has been disconnected from energized parts, locked/tagged in accordance with established standards, tested to ensure the absence of voltage, and grounded if determined necessary.

5.23 Electricity – the existence of positive and negative charges and the potential for a flow of electrons along a conductor.

5.24 Energized – electrically connected to or having a source of voltage.

5.25 Exposed – capable of being inadvertently touched or approached by a person. It is applied to parts that are not suitably guarded, isolated or insulated.

5.26 Flame-resistant (FR) – the property of a material whereby combustion is prevented, terminated, or inhibited following the application of a flaming or non-flaming source of ignition, with or without subsequent removal of the ignition source.

5.27 Flash hazard – a dangerous condition associated with the release of energy caused by an electric arc.

5.28 Flash Protection Boundary – an approach limit at a distance from exposed live parts within which a person could receive a second degree burn if an electrical arc flash were to occur.

5.29 Flash suit – a complete flame retardant clothing and equipment system that covers the entire body, except for the hands and feet. This includes pants, jacket and flash hood.

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5.30 Frequency – the number of times a waveform repeats its basic cycle each second. The unit of measurement is the hertz (Hz).

5.31 Fuse – an electrical device put in a circuit to protect against overloading. Current above the rating of the fuse will melt the fusible link and open the circuit.

5.32 Fused disconnect - a manual switching device, with fuses, used to disconnect power from a circuit or load.

5.33 Ground – a conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth, or to some conducting body that serves in place of the earth.

5.34 Ground fault – an unintentional, electrically conducting connection between an ungrounded conductor of an electrical circuit and the normally non-current-carrying conductors, metallic enclosures, metallic raceways, metallic equipment or the earth.

5.35 Ground-Fault Circuit-Interrupter (GFCI) - a device intended for the protection of personnel that functions to de-energize a circuit or portion thereof within an established period of time when a current to ground exceeds the values established for a Class A device. Class A ground-fault circuit-interrupters trip when the current to ground is 6 mA or higher and do not trip when the current is less than 4 mA.

5.36 Impedance – measure of opposition to current flow that combines the opposition from resistance and reactance. The unit of measurement is the OHM.

5.37 Incident energy – the amount of energy impressed on a surface, a certain distance from the source, generated during an electrical arc event. One of the units used to measure incident energy is calories per centimeter squared (cal/cm2).

5.38 Insulated – separated from other conducting surfaces by a dielectric (including space), offering a high resistance to the passage of current.

5.39 Insulator - is a material that does not permit free motion of electrons. It has a high resistance to current flow. Plastic, rubber, glass and ceramic are all good insulators.

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5.40 Interrupting rating – the current rating a protective device (fuse or circuit breaker) can safely interrupt. Interrupting rating is also referred to as ampere interrupting capacity.

5.41 Limited Approach Boundary – an approach limit at a distance from an exposed live part within which a shock hazard exists.

5.42 Line side - the wiring and connections on the power line (supply) side of any electrical transfer device.

5.43 Live parts – energized conductive components.

5.44 Load – the device that is being driven by the source of power. It absorbs the power from the supply voltage and converts it to heat, light, etc.

5.45 Load side - the wiring and connections on the power output (load) side of any electrical transfer device.

5.46 Lug – terminal that is soldered or crimped on the end of a wire so that it can be attached to some part of a circuit.

5.47 Motor control center (MCC) – an assembly of one or more enclosed sections having a common bus, containing motor control units.

5.48 Motor starter - an automatic (or manual) power switching device, with motor overload protection for electrical motors.

5.49 Multimeter – an instrument that can measure different values such as voltage, current and resistance.

5.50 Ohm – the basic unit of measurement for resistance.

5.51 Ohm meter – an instrument that measures electrical resistance.

5.52 Overcurrent – any current in excess of the rated current of equipment or the ampacity of a conductor. It may result from overload, short circuit or ground fault.

5.53 Overload – to apply excessive load to a device that results in a distorted output and, in some cases, damages the equipment.

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5.54 Panelboard – a single panel or group of panel units designed for assembly in the form of a single panel, including buses and automatic overcurrent devices, and equipment with or without switches for the control of light, heat or power circuits.

5.55 Qualified person – one who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved.

5.56 Resistance – the quality of a material to oppose current flow.

5.57 Restricted Approach Boundary – an approach limit at a distance from an exposed live part within which there is an increased risk of shock, due to electrical arc over combined with inadvertent movement, for personnel working in close proximity to the live part.

5.58 Shock hazard – a dangerous condition associated with the possible release of energy caused by contact or approach to live parts.

5.59 Short circuit – a condition, usually undesirable, where conductors make contact in such a way that current flows through a contact rather than through the intended path.

5.60 Step-down transformers – a transformer used to reduce the voltage.

5.61 Switch – an electrical device that opens and closes circuits. The simplest switches either turn a circuit on or off.

5.62 Switchboard – a large single panel, frame, or assembly of panels on which are mounted on the face, back or both, switches, overcurrent and other protective devices, buses and instruments.

5.63 Terminal – a point of electrical connection.

5.64 Transformer – a device that transforms voltage, current and impedance levels through the interaction of magnetic fields between two coils of wires. Energy is usually applied to the primary windings, and the transformed result is taken from the secondary windings.

5.65 Unqualified Person – a person who is not a qualified person and is not allowed to work on energized electrical equipment.

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Note: Unqualified Persons shall be trained in and familiar with any of the electrical safety related practices necessary for their safety.

5.66 Volt – the basic unit of measurement for voltage.

5.67 Voltage – the electrical force that causes electrons to flow in a complete circuit. Measure in volts (V).

5.68 Voltmeter – an instrument for measuring voltage.

6.0 ELECTRICAL SAFETY GENERAL RULES

Always de-energize equipment and systems before performing any type of work on the equipment. Troubleshooting and performing diagnostic testing on equipment are the only times employees can perform work on energized equipment.

Note: Job Briefing shall be required before starting each job, the employee in charge shall conduct a job briefing with the employees involved. The briefing shall cover such subjects as hazards associated with the job, work procedures involved, special precautions, energy source controls, and personal protective equipment requirements. See Appendix B (Job Briefing Checklist)

6.1 Always inspect the equipment before you start to perform the job task. Look for any tears/cuts in the insulation, loose wires, etc. Always verify that the equipment is in good working condition!

6.2 Only qualified persons are allowed to work on energized equipment. Unqualified persons are forbidden to work on energized equipment.

6.3 When things do not look right, or you question the integrity of the electrical system that you are working on, STOP and contact someone that will be able to help you. NEVER continue to work if you are unsure of the equipment.

6.4 Expect the unexpected and be alert at all times. A wire pops out of the panel when you open the door, someone before you left a tool in the panel, wires are old and the insulation starts to crack and fall apart. NEVER be complacent when working on electrical equipment.

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6.5 Always wear the required protective clothing and PPE when performing work on live electrical equipment (>50 V) and position yourself within the Flash Protection Boundary.

6.6 Never work on or near live electrical equipment when impaired due to illness, fatigue or other reasons.

6.7 Be alert at all times when working near live parts greater than 50 V.

6.8 Never reach blindly into areas that might contain exposed live parts where an electrical hazard may exist.

6.9 Do not enter spaces containing live parts unless illumination is provided that enables you to perform work safely.

6.10 Never work on live electrical equipment where there is a lack of illumination and/or obstructions preclude observation of the work to be performed.

6.11 All conductive tools and materials (tools, pipes, metal scaffold parts, etc.) must never come within the Flash Protection Boundary.

6.12 Never enter a Flash Protection Boundary without the required training and protective clothing and PPE.

6.13 Evaluate and control the work environment.

6.14 Plastic rimmed safety glasses with side shields and rubber soled work boots are required when working on electrical equipment.

6.15 Wear rubber-insulated gloves with leather protectors when there is a possibility that your hands may come in contact with an energized conductor.

16. Where possible, only place one hand in the panel at a time. Make sure that the free hand is not touching a grounded surface, because any current path that includes the heart (current running from hand to hand) is more likely to result in heart fibrillation than one that doesn’t.

6.17 Never assume that a piece of equipment is de-energized. Always verify with a voltmeter.

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6.18 Even after you verify that a piece of equipment is de-energized with a voltmeter, never grab a deenergized part. Always touch the de-energized part with the back of the hand first. This will eliminate your exposure to hold-on current.

6.19 Never wear jewelry of any kind while working on electrical equipment. This includes large metal belt buckles and tool belts.

6.20 Use approved insulated tools when working on an energized conductor.

6.21 Inspect the probes and rubber/plastic stops for cracks and tears before using them.

6.22 Verify that the meter and probes are rated for the voltage you are measuring.

6.23 Verify that the probes have good continuity before you take electrical readings.

6.24 Test the voltmeter on a known source (wall outlet) before and after taking electrical readings.

6.25 Wrap electrical tape around electrical switch contact screws before you place them back into an electrical box. This will help prevent grounding the switch to the metal box.

6.26 When turning off a disconnect, stand to the side, face away from the disconnect, and pull the disconnect to the off position.

6.27 Never open a disconnect under load unless it is an emergency.6.28 Use ground fault circuit interrupters (GFCI’s) when working with temporary wiring and / or using electrical power tools and / or equipment.

6.29 When you are not working inside an electrical panel, always keep electrical panel/cabinet doors closed.

6.30 Never store electrical tools, meters, parts, etc. inside an electrical panel.

6.31 When digging a trench or hole, you must always call the local Diggers Hotline and identify the utilities before you start to excavate.

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6.32 Before drilling or cutting into a wall, identify where the electrical lines, cables, phone lines, etc. are located.

6.33 Never stand in a puddle or on a wet surface while working on electrical equipment.

7.0 BASIC CONCEPTS

7.1 There are three rules that electrical current will always follow.

7.1.1 Electricity always travels in a path of least resistance, and it will always travel to ground.

7.2 To get an electrical shock, you must become part of the circuit.

7.3 Electricity needs a complete circuit in order to flow. A circuit is any path that returns to the power source. A broken wire, loose connector, or a switch in the "off" position will prevent flow. The electricity sits there and waits until the path is closed, when it continues to flow.

7.4 Understanding the relationship between current, voltage, resistance and power.

7.4.1 Current is the flow of electrons in a circuit and is measured in ampere (A). Current (Amperes) is a measurement of how many electrons flow through a device. In a water tank analogy, current would be the flow rate of the water, such as gallons per minute.

7.4.2 Voltage (V) is the force that moves electrons, forcing a current.

7.4.3 Resistance, measured in Ohms, slows down current flow. The higher the resistance of a circuit, the lower the current will be. Resistance would be equivalent to pipe size. If you have the water tank at a high level, but the exit pipe is small in diameter, there is high resistance and not much water will flow. If you use a bigger diameter pipe that offers lower resistance, the flow rate will be higher.

7.4.4 Electric power is measured in watt (W). Watts are used to measure the rate at which electric power is being used in a given amount of time. This is a factor that must be considered in determining the amount of energy used during a given period. Usually this is done by multiplying watts by hours. When power is measured in kilowatts and multiplied by hours, the result is kilowatt-hours.

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7.5 Ohm’s Law

Ohm’s law is the relationships between voltage, current and resistance.

8.0 ELECTRICAL HAZARDS

The three main electrical hazards are shock, arc, and blast.

8.1 ShockElectricity travels in closed circuits, and its normal route is through a conductor. Shock occurs when the body becomes a part of the circuit. The current enters the body at one point and exits at another. Every year employees receive electrical shocks that result in severe burns and scarring.There are three primary reasons why these shocks occur:

- Employees perform work on energized electrical equipment, are careless and become part of the circuit. Most commonly, an employee uses an un-insulated tool and grounds that tool to an energized part.- Employee fails to de-energized and lockout the system before they perform service on the equipment.- Employees’ lockout and tagout the equipment but fail to verify that the equipment is de-energized.

8.1.1 Factors determining severity of shock.Shocks can be anything from mild to deadly. The severity of the shock depends on many factors, including the amount, path and type of current, the exposure length, the condition of the victim, contact pressure, and skin resistance.

a. Current path Current may pass through the body from:

Head to toe Arm to leg Arm to arm

Arm to arm is the most common flow. This is usually a result of placing both hands inside a panel when taking electrical readings. To avoid this situation, University of South Carolina requires employees to use an alligator clip. The alligator clip is used to complete a contact to the ground. This allows the employee to work with only one hand inside the panel.

b. Individual heart reaction

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The heart is the most critical organ in the case of an electrical shock. How the heart will react to an electrical shock depends on the condition of the individual's heart. Everyone reacts differently to an electrical shock.

c. Skin attributesThe condition of the skin also plays an important role. With very dry skin, a high voltage shock could produce a severe burn without necessarily electrocuting the victim. Lower voltage applied to wet or sweaty skin could cause death without any evidence of burning, particularly if the path of the current is across the chest.

8.1.2 Range of current and the reaction.

Amount of Current ReactionLess than 1 milliampere Nothing.1 – 5 milliampere Slight but not painful shock. It is still

possible to let go of the circuit.5 - 10 milliampere Painful shock, but muscles can still be

controlled.10 - 20 milliampere Severe pain, loss of muscle control and

inability to let go of circuit.20 - 50 milliampere Severe pain and labored breathing.

50 - 200 milliampereSevere pain, an agitated heart, erratic heartbeat and possible loss of consciousness

50 - 200 milliampere Severe pain, an agitated heart, erratic heartbeat and possible loss of consciousness

Over 200 milliampere Severe pain, serious burns and possible heart stoppage.

8.1.3 Secondary injuries resulting from an electrical shock. Anything that causes you to react in an unplanned manner can cause an accident.

Injuries caused by the aftermath of an electrical event include: Shock Burn Hearing loss Eye damage Cuts/bruises

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Broken bones

8.1.4 Electricity’s effect on the human body.a. Electricity’s effect on the human heart.

8.1.4.1 Understanding the human heart and its capabilities.

The blood is the transport system by which oxygen and nutrients reach the body’s cells and waste materials are carried away. The heart, a muscular organ positioned behind the ribcage and between the lungs, is the pump that keeps this transport system moving. Blood leaves the left side of the heart and travels through arteries, which gradually divide into capillaries. In the capillaries, food and oxygen are released to the body cells, and carbon dioxide and other waste products are returned to the bloodstream. The blood then travels in veins back to the right side of the heart, where it is pumped directly to the lungs. In the lungs, carbon dioxide is exchanged for oxygen. This renewed blood flows back to the left side of the heart, and the whole process begins again. It is important that fresh blood from the aorta goes directly to the brain, because without constant oxygen the brain will be irreversibly damaged.

8.1.4.2 Exposure to electric current can cause major heart disruptions.

a. Ventricular fibrillation is when the right and left side contractions will cease to be coordinate. In this state, the little bundles of muscle surrounding the heart cease to contract in unison and start to tremble or twitch so that no effective pumping action is produced.

b. Cardiac arrest is when the heart stops completely.

b. Electricity's effect on human muscles.

The negative effect electric current has on muscles is that it causes them to get shorter or contract.

8.1.5 PULMONARY PARALYSIS. Passage of continuous current through the chest cavity can cause the chest muscles to contract - constantly - and restrict breathing. This is called pulmonary paralysis.

8.1.6 HOLD-ON CURRENT.

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Muscles have pairs - flexors and extensors. The flexors are stronger than the extensors. This means that gripping strength is stronger than releasing ability. When person grabs an energized electric line, the current goes down their arm to the muscles, and the current tells the muscles to contract. The hand closes. They can't open their hand up because the electricity is causing the hand to close, not their brain. This is called hold-on current. It can happen with even a small amount of current - as little as 12 milliamperes.

The danger with hold-on current is that unless you can manage to pull away or unless somebody cuts the power to the circuit, you're stuck there. Sometimes the only way to free yourself is to attempt to fall away, letting your weight physically break you from the contact.

Remember that if you see someone held-on; first try to de-energize the equipment by shutting off the power. If necessary, push the individual away with a nonconductive material (wooden board, etc.).

8.2 Arc

Electric arcs are extremely dangerous because they may produce a flash, cause an explosion, and generate temperatures in excess of 35,000 degrees Fahrenheit. There is no material on earth that can withstand this temperature. This heat is four times greater than the surface temperature of the sun.

Burns are the most frequent injury associated with electric current. Heat is developed from the combination of current and resistance. The severity of the burn depends on the degree of thermal energy. This is called the incident energy and is measured in cal/cm2. Second degree burns result when the skin is exposed to approximately1.2 cal/cm2. The goal is to protect employees from experiencing burns greater than second degree burns when they are exposed to an arc flash.

Electrical burns are often more severe than they appear to be from the outside. Injury occurs not only at the contact site, but also along the path the electricity takes, and at the exit point. Frequently, there is also extensive muscle damage that will not be evident from a visual examination of the skin. Deep burns result in unsightly scars that will often continue to enlarge for 12 – 18 months after the burn occurs. These scars are not only a cosmetic problem, but may seriously interfere with joint function. Burns that occur at 140-degrees Fahrenheit or less are reversible. Burns hotter than that are not. The cells have changed such that the damage is permanent.

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There are three kinds of burns associated with electrical shock. They are electrical burns, arc burns, and thermal contact burns.

8.2.1 Arc burns are the result of high temperatures near the body. Arcs can cause fatal burns within five feet of the arc, and disabling burns within ten feet.

8.2.2 Electrical burns are the result of the electric current flowing through the tissue or bone. Experts have long believed that tissue damage in burn victims was caused by heat generated by the passage of current. Recent medical research at the University of Chicago found that electrical burns cause enlargement of pores in cell membranes which allow ions to flow freely, leading to cell death. This causes irreversible damage to the tissue.

8.2.3 Thermal contact burns are those normally experienced when the skin comes in contact with hot surfaces of overheated electric conductors, conduits, or other energized equipment. Additionally, clothing may be ignited in an electrical accident, and a thermal burn will result. All three types of burns may be produced simultaneously. The degree of burning will depend upon the energy at the point of contact and its duration. Please be careful when dealing with a burn injury. What may look like a superficial burn might be severe! The density will be greatest at the point of contact, and the current may destroy tissue under what appears to be a superficial skin burn. Medical attention is critical since the dead tissue may be blocking the bloodstream, resulting in decaying and rotting of the tissue.

8.3 Blast

The blast comes from the pressure developed by the instantaneous heating of the air surrounding the arc and from the expansion of the metal as it is vaporized.

There are three major hazards that are created by the arc’s blast.

8.3.1 Physical hazards. The electrical energy at the fault is changed into other forms of energy like high thermal radiation; damaging noise levels; explosive expansion of surrounding air due to high temperatures; and vaporization or splattering of conductors and metal components.

8.3.2 The pressure wave is created by a high-energy arcing fault. The individual that is exposed to the pressure wave will be propelled away, decreasing their exposure and the burns associated with a fault. The hazard comes from being propelled into other objects while being thrown. Hearing

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damage and possible concussion can occur. Pressure waves can be strong enough to propel large objects, like panels, over a distance of many yards. Pressures have been high enough to knock over a standard construction wall.8.3.3 Projectiles. The arc will melt electrical components and the pressure wave will blast the molten particles and other equipment.

9.0 BECOMING PART OF A CIRCUIT

9.1 Ten common electrical hazards in our industry: Conductive tools, ladders and equipment used near electrical conductors Damaged insulation on electrical cords and tools Insulated tool handles with damaged or missing insulation No Ground Fault Circuit Interrupter (GFCI) protection when using portable

cords and tools in wet conditions Detached conduits, missing covers, defective wiring and other wiring code

violations Misuse of electrical testing equipment Switches or resets located inside electrical panels Exposed wire ends or terminals in crawl spaces, attics and other seldom

visited places Broken/missing ground prongs on power cords Lack of lockout where circuits should be de-energized before working on

them

9.2 Four common situations that can lead to an electrical shock or arc

9.2.1 Touching an insulated conductor on which the insulation has deteriorated or been damaged so that it is no longer protective This type of contact commonly happens when employees are working on old equipment or working on the wiring of an old building. The majority of contact comes from pulling or pushing on wires, trying to either arrange them so a measurement can be taken or placing them back into a box or panel. This pulling and pushing causes the insulation to crack or break away, exposing the wire.

This is a common hazard when taking an electrical reading from a light switch.

In addition to stress, insulation can fail as a result of experiencing excessively high voltage, temperature extremes, chemical reactions, or high moisture.

Use extra care with old wiring and insulation that's been exposed to chemicals.

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9.2.2 Another common way employees receive electrical shocks is when equipment fails, resulting in an open or short circuit. A short circuit occurs when the conductors bypass the load, since current follows the path of least resistance. This may occur due to poor electrical contact, failed insulation, or a loose wire or tool hitting a grounded source.

This is most common when working in a panel or disconnect, and the individual grounds a screwdriver.

9.2.3 Faulty temporary wiring can also cause shocks. Temporary wiring goes through wear and tear on a daily basis. This wear and tear can create problems with the grounding continuity. Once the ground wire becomes damaged and continuity is lost, the risk of electrical shock greatly increases. The best protection is the use of a ground-fault circuit interrupter (GFCI).

9.2.4 Drilling and cutting into walls, floors and ceilings are common tasks for University of South Carolina employees. The hazard lies in striking a hidden electrical line, cable or other utility. Contact the customer to help you locate any power lines that may be in your path.

Note: In some rare situations, employees may be required to dig a hole or trench. Always call your local PUPS Hotline at least three days before doing any excavation. If you run into a continuous piece of tape while excavating that means that either an electric, gas, or fiber optic line is below the tape. Stop working immediately and call your supervisor, customer contact, and your local Diggers Hotline for help.

10.0 LIVE ELECTRICAL WORK

10.1 Conditions for live electrical work.

This University of South Carolina Program requires all equipment be de-energized “Lockout/Tagout/Tried” if it is to be worked on. The only two exceptions to this Program are: When continuity of service is required (troubleshooting and performing diagnostic testing).

Important Note: When working on energized electrical conductors or circuit parts that are not placed in an electrical safe condition “Lockout/Tagout/Tried” (i.e., for the reasons of increased or additional hazards or infeasibility per NFPA 70-E 130.1), work to be performed shall be considered energized electrical work and

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shall not be perform without a completed written permit. See NFPA 70-E 2009 Edition Annex J “Energized Electrical Work Permit”

10.2 Arc flash boundaries

There are four boundaries that need to be taken into consideration when approaching exposed energized conductors. Employees that approach any of these boundaries need to protect themselves from two primary hazards: Arcing, and Shock. An arcing fault which can result from mechanical failure or human error is created when current flows through the air between phase conductors, or phase conductors and neutral or ground. Arcs can be produced by dropping tools, accidental contact with energized components, or through the use of improper work procedures. In addition to temperatures as high as 35,000°F, an arc can generate a flash and blast that can create molten metal, pressure and sound waves, shrapnel, and intense light. Shock can occur when a part of the body completes a circuit between two conductors or a grounding source.

Only authorized employees are allowed to work within the following four boundaries. Unauthorized workers are not allowed to work within any of the four boundaries.

The four boundaries are:

a. Flash Protection Boundary – The distance from exposed live parts within which a person could receive a second degree burn if an electrical arc flash were to occur.

b. Limited Approach Boundary – The distance from an exposed live part within which a shock hazard exists.

c. Restricted Approach Boundary – The distance from an exposed live part within which there is an increased risk of shock due to an electrical arc, combined with inadvertent movement, for individuals working in close proximity to the live part.

d. Prohibited Approach Boundary – The distance from an exposed live part within which work is considered the same as making contact with the live part.

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Nominal SystemVoltage Range,Phase to Phase

Exposed MovableConductor

Exposed FixedCircuit Part

RestrictedApproachBoundary

ProhibitedApproach Boundary

Less than 50 Not specified Not specified Not specified Not specified50 to 300 3.05m (10 ft 0in) 1.07 m (3 ft 3 in.) Avoid contact Avoid contact301 to 750 3.05 m (10 ft 0 in.) 1.07 m (3 ft 6 in) 304.8 mm (1 ft 0 in.) 25.4 mm (0ft 1 in.)751 to 15 kV 3.05 m (10 ft 0 in.) 1.53 m (5 ft 0 in.) 660.4 mm (2 ft 2 in) 177.8 mm (0 ft 7 in.)15.1 kV to 36 kV 3.05 m (10 ft 0 in.) 1.83 m (6 ft 0 in.) 787.4 mm (2 ft 7 in.) 431.8 mm (1 ft 5 in.)36.1 kV to 46 kV 3.05 m (10 ft 0 in.) 2.44 m (8ft 0 in.) 838.2 mm (2 ft 9 in.) 431.8 mm (1 ft 5 in.)46.1 kV to 72.5 kV 3.05 m (10 ft 0 in.) 2.44 m (8 ft 0 in.) 965.2 mm (3 ft 3 in.) 635 mm (2 ft 2 in.)72.6 kV to 121 kV 3.25 m (10 ft 8 in.) 2.44 m (8 ft 0 in.) 991 mm (3 ft 4 in.) 812.8 mm (2 ft 9 in.)138 kV to 145 kV 3.36 m (11 ft 0 in.) 3.05 m (10 ft 0 in.) 1.093 m (3 ft 10 in.) 939.8 mm (3 ft 4 in.)161 kV to 169 kV 3.56 m (11 ft 8 in.) 3.56 m (11 ft 8 in.) 1.22 m (4 ft 3 in.) 1.07 m (3 ft 9 in.)230 kV to 242 kV 3.97 m (13 ft 0 in.) 3.97 m (13 ft 0 in.) 1.6 m (5 ft 8 in.) 1.45 m (5 ft 2 in.)345 kV to 362 kV 4.68 m (15 ft 4 in.) 4.68 m (15 ft 4 in.) 2.59 m (9 ft 2 in.) 2.44 m (8 ft 8 in.)500 kV to 550 kV 5.8 m (19 ft 0 in.) 5.8 m (19 ft 0 in.) 3.43 m (11 ft 10 in.) 3.28 m (11 ft 4 in.)765 kV to 800 kV 7.24 m (23 ft 9 in.) 7.24 m (23 ft 9 in.) 4.55 m (15 ft 11 in.) 4.4 m (15 ft 5 in.)

10.3 Electrical exposure

Employees who are working on energized electrical equipment greater than 50 V and are working within the Flash Protection Boundary are considered to be EXPOSED and need to wear the appropriate clothing and personal protective equipment.

Factors influencing the need/type of personal protective equipment (PPE)

10.3.1 Evaluate the equipment that you are working on and the tasks that you need to perform. Ask yourself these eight questions. To determine whether or not the standard UNIVERSITY OF SOUTH CAROLINAPPE/uniform guidelines apply to the work that you are performing. If the standard guidelines do not apply please contact your supervisor.

a. Is the equipment in good condition or does something look unusual?

If the equipment looks dented, smashed, broken, etc. please stop work immediately and contact your supervisor.

b. Will the circuit breaker protecting the equipment actually work?

For example, some breakers have never been exercised and may not work when necessary. It is common practice to exercise breakers every two to three years.

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If you believe the breaker will not work when it needs to because of its poor or damaged condition, please stop work and contact your supervisor.

c. How close will you be to the exposed energized components?

Because the risk becomes greater the closer you are to the arc/flash, you may need to wear additional/alternative PPE.

d. How much current is there? The greater the amount of amps available means the greater energy potential.

e. How close are you to the power source?Fault current decreases the farther you are from the “up stream” power source. For example, the fault current would be much higher if you were working on a 480 V chiller starter 30 feet from its power source than if you were working on a roof top unit 500 feet away. The closer the power source the greater the fault current.

f. Can you keep those around you at least six feet away from the exposed live conductors? If this could be a problem use red “DO NOT ENTER” tape to restrict access.

Do not carry on conversations with workers, contractors, subcontractors, customers, etc. who are not wearing the required uniform or PPE within the flash protection boundary.

g. Will you be working on the equipment at an elevated level such as a ladder, platform or roof?

When working on energized equipment, make note of where you are standing and how your body is positioned. If you were to become part of the circuit, could you be freed without being exposed to a secondary hazard that is also life threatening (ie. fall from a ladder, etc.) or limit your ability to be freed because of limited access?

h. What are the consequences if something goes wrong?Never make the assumption that an arc flash will not happen to you. Be prepared and follow the required safe work practices when working on live electrical equipment!

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10.4 Incident Energy

Incident energy is the amount of energy created by an arc flash and is measured in calories per square centimeter (cal/cm2). The following three factors contribute to the amount of energy that is created by an arc flash.

a. Magnitude of the arc flash – the greater the amount of amps available means the greater energy potential.

b. Length of the blast – the longer the blast continues the greater the energy released.c. Distance from the flash source - incident energy decreases as distance from the flash source increases.

10.5 Protective devices

The amount of energy released during an arcing fault is based on two characteristics of the protective device protecting the affected circuit. These two characteristics are:

a. The time it takes the protective device to open.

b. The amount of fault current the protective device allows through.For example: the faster the fault is cleared by the protective device, the lower the amount of energy released. If the protective device can also limit the current, reducing the actual fault current flowing through the arc, the lower the energy released.

10.6 Interrupting rating

NOTE: Please use the following as a guideline only. Be careful when relying on circuit breakers for protection, as they are just like other mechanical devices. If they are not maintained properly, are located in a dirty environment, or are exposed to airborne chemicals, they may not operate as you’d expect.

The current rating a protective device (fuse or circuit breaker), can safely interrupt. Interrupting rating is also referred to as ampere interrupting capacity.

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Circuit breakers can be rated in various increments between 5,000 A (the minimum rating allowed) and 200,000 A. The interrupting rating is dependent upon voltage. The interrupting rating on a circuit breaker at 240 V may equal 18,000 A. However, the same circuit breaker at 480 V has an interrupting rating of 14,000 A.The following table identifies interrupting ratings for some common breakers and fuses:

Circuit Breakers Rating15 A 120 V circuit breaker 10,000 A20 A 240 V circuit breaker 10,000 A30 A 120/240 V circuit breaker 10,000 A20 A 240 V circuit breaker 1 ph 10,000 A 3 ph 5,000 A20 A 277 V circuit breaker 277 V ~14,000 A 125 DC 10,000 A100 A 600 V circuit breaker 600 V 14,000 A 480 V 14,000 A 240 V 18,000 A

Fuse RatingFRN 3.5 A 250 V fuse 200,000 A

FRS-R 30 A 600 V fuse 200,000 AFRN-R 60 A 250 V fuse 200,000 AFRN 200 A 250 V fuse 100.000 A

As shown above, circuit breakers have lower interrupting ratings than fuses. Knowing how the equipment being worked on is protected—by either a circuit breaker or fuse, will help establish the interrupting rating of that equipment and the personal protective and safety equipment required when working on it. Equipment protected by circuit breakers rated for interrupting ratings of 10,000 A and below allow a decrease in the hazard class by one.

10.7 Using PPE

When working within the Flash Protection Boundary (exposure to incident energy greater than 1.2 cal/cm2), employees are required to wear the required personal protective and safety equipment. Employees not wearing the appropriate protective clothing and equipment must stay outside of the Flash Protection Boundary at all times.

a. All employees are required to wear safety glasses with side shields at all times!

b. Meltable fibers like nylon, polyester and spandex cannot be worn as an outer or under layer when working within a Flash Protection Boundary with exposed live energized parts greater than 50 V.

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c. All PPE must be inspected prior to use including FR uniforms and coveralls. Defective equipment will be taken out of service immediately.

d. FR clothing must cover all ignitable clothing.

e. FR clothing and PPE must allow the employee to move freely and allow for good visibility.f. Tight-fitting FR clothing must not be allowed due to the decrease in protection. Loose fitting FR clothing provides air gaps that increase the level of thermal protection.

g. FR clothing must fit properly so that it does not interfere with the work task.

2. Washing/drying/repairing Indura cotton FR clothing

When washing, drying and repairing Indura cotton (FR clothing), the following considerations apply:a. Always pre-wash your FR clothing prior to wearing it for the first time. This will remove any residual chemicals on the fabric from the manufacturing process. The washing temperature should not exceed 160 F.

b. Do not wash your FR garments with any other garments. Fibers from the non-FR clothing can accumulate on the FR garments and ignite during a flash arc.

c. Do not bleach FR garments when washing. Bleaching will reduce the flame resistant qualities.d. Tumble dry your garments and remove them immediately from the dryer. To help reduce shrinkage they should be left a little damp. Do not leave the garments sitting in a hot dryer when the tumbler is not in motion. Do not use drying temperatures above 160 F.

e. Repairs must be done using FR approved thread and patching material.

Note: The following is from the NFPA 70E 2009 Edition tables 130.7 (C) (9) and 130.7 (C) (10).

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Table 130.7(C) (9) Hazard/Risk Category Classifications and Use of Rubber Insulating Gloves and Insulatedand Insulating Hand Tools

Task PerformedEquipment 240 V and

BelowHazard/Risk Rubber Insulating Gloves Insulated Hand Tools

Inspection outside the restricted approach boundary

0 N N

Circuit breaker (CB) or fused switch operation with covers on

0 N N

CB or fused operation with covers off 0 N N

Working on energized parts, including voltage testing

1 Y Y

Remove/install CBs or fused switches 1 Y Y

Removal of bolted covers 1 N N

Opening hinged covers 0 N N

Working on energized electrical conductors and circuit parts of utilization equipment fed directly by branch circuit of the panelboard

1 Y Y

Task PerformedEquipment >240 V and up

to 600 VHazard/Risk Rubber Insulating Gloves Insulated Hand Tools

Inspection outside the restricted approach boundary

1 N N

Circuit breaker (CB) or fused switch operation with covers on

0 N N

CB or fused operation with covers off 1 Y N

Working on energized parts, including voltage testing

2* Y Y

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Working on energized electrical conductors and circuit parts of utilization equipment fed directly by branch circuit of the panelboard

2* Y Y

Task Performed Hazard/Risk Rubber Insulating Gloves Insulated Hand Tools

600 V Class Motor Control Centers (MCCs) - Note 2

(except as indicated)

Perform infrared thermography and other non-contact inspections outside the restricted approach boundary

1 N N

CB or fused switch or starter operation with enclosure doors

closed

0 N N

Reading a panel meter while operating a meter switch 0 N N

CB or fused switch or starter operation with enclosure doors open

1 N N

Work on energized electrical conductors and circuit parts, including voltage testing

2* Y Y

Work on control circuits with energized electrical conductors and circuit parts 120 V or below, exposed

0 Y Y

Work on control circuits with energized electrical conductors and circuit parts > 120 V, exposed

2* Y Y

Insertion or removal of individual starter "buckets" from MCC - Note 3

4 Y Y

Application of safety grounds, after voltage test 2* Y Y

Removal of bolted covers (to expose bare, energized electrical conductors and circuit parts) - Note 3

4 N N

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Opening hinged covers (to expose bare, energized electrical conductors and circuit parts) - Note 3

1 N N

Work on energized electrical conductors and circuit parts of utilization equipment fed directly by a branch circuit of the.motor control center

2* Y Y


600 V Class Switchgear (with power circuit breakers or fused

switches) - Note 4

Perform infrared thermography and other non-contact inspections

outside the restricted approach boundary

2 N N

CB or fused switch operation with enclosure doors closed 0 N N


CB or fused switch operation with enclosure doors open 1 N N

Work on energized electrical conductors and circuits parts, including voltage testing

2* Y Y

Work on control circuits with energized .electrical conductors and circuit parts 120 V or below, exposed

0 Y Y

Work on control circuits with energized electrical conductors and circuit parts >120 V, exposed

2* Y Y

Insertion or removal (racking) of CBs from cubicles, doors open or closed

4 N N

Application of safety grounds, after voltage test 2* Y N

Removal of bolted covers (to expose bare, energized electrical conductors and circuit parts)

4 N N

Opening hinged covers (to expose bare, energized electrical conductors and circuit parts)

2 N N

Other 600 V Class (277 V through 600 V, nominal)Equipment - Note 2 (except as indicated)

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Lighting or small power transformers (600 V, maximum)Removal of bolted covers (to expose bare, energized electrical conductors and circuit parts)

2* N N


1 N N


Work on energized electrical conductors and circuit parts,including voltage testing

2* Y Y


Revenue meters (kW-hour, at primary voltage and current) In-section or removal

2* Y N

Cable trough or tray cover removal or installation 1 N N

Miscellaneous equipment cover removal or installation 1 N N

Work on energized electrical conductors and circuit parts, including voltage testing

2* Y Y


Insertion or removal of plug-in devices into or from busways 2* Y N

NEMA E2 (fused contactor) Motor Starters, 2.3 kVThrough 7.2 kV

Perform infrared thermography and other non-contact inspec-tions outside the restricted approach boundary

3 N N

Contactor operation with enclosure doors closed 0 N N


Contactor operation with enclosure doors open 2* N N

Work on energized electrical conductors and circuit parts, including voltage testing

4 Y Y

Work on control circuits with energized electrical conductors and circuit parts 120 V or below, expos d

0 Y Y

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3 Y Y

Insertion or removal (racking) of starters from cubicles, doors open or closed

4 N N


Application of safety grounds, after voltage test 3 Y N


4 N N

Opening hinged covers (to expose bare, energized electrical

conductors and circuit parts)

3 N N

Insertion or removal (nicking) of starters from cubicles of arc-resistant construction, tested in accordance with IEEEC37.20.7, doors closed only

0 N N

Metal Clad Switchgear, 1kV Through 38 kV

Perform infrared thermography and other non-contact inspections outside the restricted approach boundary

3 N N

CB operation with enclosure doors closed 2 N N


CB operation with enclosure doors open 4 N N

Work on energized electrical conductors and circuit parts, including voltage testing

4 Y Y

Work on control circuits with energized electrical conductors and circuit parts 120 V or below, exposed

2 Y Y


4 Y Y

Insertion or removal (racking) of CBs from cubicles, doors open or closed

4 N N

Application of safety grounds, after voltage test 4 Y N

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4 N N


3 N N


Opening voltage transformer or control power transformer compartments

4 N N

Arc-Resistant Switchgear Type 1or 2 (for clearing timesof <0.5 see with a perspective fault current not toexceed the arc resistant rating of the equipment)

CB operation with enclosure door closed

0 N N

Insertion or removal (racking) of CBs from cubicles, doors closed

0 N N

Insertion or removal of CBs from cubicles with door open

4 N N

Work on control circuits with energized electrical conductorsand circuit parts 120 V or below, exposed

2 Y Y

Insertion or removal (racking) of ground and test device with door closed

0 N N

Insertion or removal (racking) of voltage transformers on or off the bus door closed

0 N N

Other Equipment 1 kV Through 38 kV

Metal-enclosed interrupter switchgear, fused or unfused

Switch operation of arc-resistant-type construction, tested in accordance with IEEE C37.20.7, doors closed only

0 N N

Switch operation, doors closed 2 N N

Work on energized electrical

conductors and circuit parts, including voltage testing

4 Y Y

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4 N N

Opening hinged covers (to expose bare, energized electricalconductors and circuit parts)

3 N N


Outdoor disconnect switch operation (hooks tick operated)

3 Y Y

Outdoor disconnect switch operation (gang-operated, fromgrade)

2 Y N

Insulated cable examination, in manhole or other confined space

4 Y N

Insulated cable examination, in open area

2 Y N

General Notes (applicable to the entire table):

(a) Rubber insulating gloves are gloves rated for the maximum line-to-line voltage upon which work will be done.

(b) Insulated and insulating hand tools are tools rated and tested for the maximum line-to-line voltage upon which work will be done, and are manufactured and tested in accordance with ASTM F 1505, Standard Specification for Insulated and Insulating Hand Tools.

(c) Y = yes (required), N = no (not required).

(d) For systems rated less than 1000 volts, the fault currents and upstream protective device clearing times are based on an 18 in. working distance.

(e) For systems rated 1 kV and greater, the Hazard/Risk Categories are based on a 36 in. working distance.

(f) For equipment protected by upstream current limiting fuses with arcing fault current in their current limiting range (V2 cycle fault clearing time or less), the hazard/risk category required may be reduced by one number.

Specific Notes (as referenced in the table):

1. Maximum of 25 kA short circuit current available; maximum of 0.03 see (2 cycle) fault clearing time.

2. Maximum of 65 kA short circuit current available; maximum of 0.03 sec (2 cycle) fault clearing time.

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3. Maximum of 42 kA short circuit current available; maximum of 0.33sec (20 cycle) fault clearing time.

4~Maximum of 35 kA short circuit current available; maximum of up to 0.5 see (30 cycle) fault clearing time.

Below are 4 examples of task performed with PPE and tool requirements:

Tasks Preformed on Energized Equipment Panelboards or Other Equipment Rated 240 V and Below

Operation of circuit breaker with covers on

Clothing - Nonmelting or Untreated Natural Fibers or FR Shirt (long sleeve), Pants (long)

Safety Glasses (nonconductive) Hearing Protection Leather Gloves (as needed)

Tasks Preformed on Energized Equipment Panelboards or Other Equipment Rated 240 V and Below

Working on energized electrical conductors and circuit parts, including voltage testing within 4 ft

FR clothing, minimum Arc Rating of 4 Shirt (long sleeve) Pants (long) Or Coveralls Arc-rated face or flash suit hood Hard Hat (E-rated) Safety Glasses (nonconductive) Hearing Protection Insulated Gloves Leather Work Shoes (nonconductive) Electrical Rated Tools Barricade with safety signs

_____________________________________________________________________________________

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Tasks Preformed on Energized Equipment Panelboards or Switchboards Rated >240 V up to 600 V (Fixed Circuit Part) within 4 ft

Circuit breaker switch operations with covers off

FR clothing, minimum Arc Rating of 4 Shirt (long sleeve) Pants (long) Or Coveralls Arc-rated face shield or flash suit hood Hard Hat (E-rated) Safety Glasses (nonconductive) Hearing Protection Insulated Gloves Leather Work Shoes (nonconductive) Electrical Rated Tools Barricade with safety signs

Tasks Preformed on Energized Equipment Panelboards or Switchboards Rated >240 V up to 600 V (Fixed Circuit Part) within 4 ft

Working on energized electrical conductors and circuit parts, including voltage testing

FR clothing, minimum Arc Rating of 8 Shirt (long sleeve) Pants (long) or Coveralls Arc-rated face shield and sock hood or flash suit hood Hard Hat (E-rated) Safety Glasses (nonconductive) Hearing Protection Insulated Gloves Leather Work Shoes (nonconductive) Electrical Rated Tools Barricade with safety signs

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Table 130.7(C) (10) Protective Clothing and Personal Protective Equipment (PPE)

Hazard/Risk Category Protective Clothing and PPE

Hazard/Risk Category 0

Protective Clothing, Nonmelting (according toASTM F 1506-00) or Untreated Natural FiberFR Protective Equipment

Shirt (long sleeve)Pants (long)Safety glasses or safety goggles (SR)Hearing protection (ear canal inserts)Leather gloves (AN) (Note 2)


FR Clothing, Minimum Arc Rating of 4 (Note 1)

Arc-rated long-sleeve shirt (Note 3)Arc-rated pants (Note 3)Arc-rated coverall (Note 4)Arc-rated face shield or arc flash suit hood (Note 7)Arc-rated jacket, parka, or rainwear (AN)FR Protective Equipment Hard hat ISafety glasses or safety goggles (SR)Hearing protection (ear canal inserts)Leather gloves (Note 2)Leather work shoes (AN)



Arc-rated long -sleeve shirt (Note 5)Arc-rated pants (Note 5)Arc-rated coverall (Note 6)Arc-rated face shield or arc flash suit hood (Note 7)Arc rated jacket, parka, or rain wear (AN)Hard hatSafety glasses or safety goggles (SR)Hearing protection (ear canal inserts)Leather gloves (Note 2)Leather work shoes

Hazard/Risk Category 2*


Arc-rated long-sleeve shirt (Note 5)Arc-rated pants (Note 5)Arc-rated coverall (Note 6)Arc-rated arc flash suit hood (Note 10)Arc-rated jacket, parka, or rainwear (AN)Hard hatSafety glasses or safety goggles (SR)Hearing protection (ear 'canal inserts)Leather gloves (Note



Arc-rated long-sleeve shirt (AR) (Note 8)Arc-rated pants (AR) (Note 8)Arc-rated coverall (AR) (Note 8)Arc-rated arc flash suit jacket (AR) (Note 8)Arc-rated arc flash suit pants (AR) (Note 8)Arc-rated arc flash suit hood (Note 8)Arc-rated jacket, parka, or rainwear (AN)Hard hatFR hard hat liner (AR)Safety glasses or safety goggles (SR)Hearing protection (ear canal inserts)Arc-rated gloves (Note 2)Leather work shoes


FR Clothing, Minimum Arc Rating of 40 (Note 1)Arc-rated long-sleeve shirt (AR) (Note 9)Arc-rated pants (AR) (Note 9)Arc-rated coverall (AR) (Note 9)Arc-rated arc flash suit jacket (AR) (Note 9)Arc-rated arc flash suit pants (AR) (Note 9)Arc-rated arc flash suit hood (Note 9)Arc-rated jacket, parka, or rain wear (AN)Hard hat

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FR hard hat liner (AR)Safety glasses or safety goggles (SR)Hearing protection (ear canal inserts)Arc-rated gloves (NoteLeather work shoes

AN = As needed (optional)AR = As requiredSR = Selection requiredNotes:

1. See Table 130.7(C) (1l). Arc rating for a garment or system of garments is expressed in cal/cm".

2. If rubber insulating gloves with leather protectors are required by Table 130.7(C) (9), additional leather or arc-rated gloves are not required. The combination of rubber insulating gloves with leather protectorssatisfies the arc flash protection requirement.

3. The FR shirt and pants used for Hazard! Risk Category 1 shall have a minimum arc rating of 4.

4. Alternate is to use FR coveralls (minimum arc rating of 4) instead of FR shirt and FR pants.

5. FR shirt and FR pants used for Hazard! Risk Category 2 shall have a minimum arc rating of 8.

6. Alternate is to use FR coveralls (minimum arc rating of 8) instead of FR shirt and FR pants.

7. A face shield with a minimum arc rating of 4 for Hazard/Risk Category I or a minimum arc rating of 8for Hazard/Risk Category 2, with wrap-around guarding to protect not only the face, but also the forehead, ears, and neck (or, alternatively, an arc-rated arc flash suit hood), is required.

8. An alternate is to use a total FR clothing system and hood, which shall have a minimum arc rating of 25 for Hazard/Risk Category 3.

9. The total clothing system consisting of FR shirt and pants and/or FR coveralls and/or arc flash coat andpants and hood shall have a minimum arc rating of 40 for Hazard/Risk Category 4.

10. Alternate is to use a face shield with a minimum arc rating of 8 and a balaclava (sock hood) with aminimum arc rating of 8 and which covers the face, head and neck except for the eye and nose areas.

10.8 Labeling requirements

University of South Carolina is responsible for complying with NEC labeling requirements. Complying with the labeling requirements is not the responsibility of the equipment manufacturers or installers.

All switchboards, panel boards, industrial control panels and motor control centers installed after 2002 needs to be labeled to warn against possible Arc Flash Hazard. Equipment installed before 2002 must be labeled when modified or upgraded.

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Note: All electrical panels and equipment must be kept clear and free from obstacles at all times.

There are several types of labels ranging from basic to labels that have the specific hazard analysis information including the Flash Protection Boundary, Flash Hazard Category, Arc Rating (cal/cm2) and PPE requirements.

Example Label:

10.9 Insulated tools

UNIVERSITY OF SOUTH CAROLINA employees should never be working on or near energized parts with any type of hand tools. However, there may be some special circumstances that will require the use of insulated tools.

Insulated tools will be used whenever tools might make accident contact with energized parts. Insulated tools will be:

10.9.1 Rated for the voltage that is present.

10.9.2 Inspected prior to use.

10.9.3 Constructed with two color layer insulation so that a visual inspection can detect insulation damage.

10.9.4 Properly stored and maintained.

11.0 EQUIPMENT

11.1 Common electrical equipment in the HVAC field.

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Please keep in mind that when working with panels and disconnects, there can be two or more sources of power. Usually the second source is the control voltage. The only way that you can determine how many power sources are in a panel is by examining the panel and using your voltmeter to verify that either the equipment is energized or de-energized.

11.2 Starter panel.

STARTER PANELS can be considered as just big on-off switches. The job of the starter panel is to provide power to run the load when needed, and to shut off the power to the load off when it is not needed. The power enters the panel and travels to the panels on/off master disconnect switch fuses, and down and out to the line side of the contactors. If the contactors’ coils are not energized, the line power is interrupted. When the contactor coils are energized, contact is made and power flows out of the panel to the load.

11.3 Hand-off-auto switch.

Please note that when working on equipment that has a hand-off-auto or on-off-auto switch, the switch may not be wired to perform the functions that are labeled on the switch. There is equipment that can be damaged if left on for a period of time.

For example: A compressor may have an on-off-auto switch but the on side of the switch is not wired. This is done so that the compressor is not accidentally left in the on mode. If left on, the compressor would run until it burned out.

11.4 Control panel.

The CONTROL PANEL gives the starter panel the information it needs to activate the starters and motors. The control panel may have many sources of power but in most cases the power to energize the starter contacts comes from a control transformer in the starter panel. The step down transformer may provide a fused 120-volt power supply.

11.5 Motor control center.

The MOTOR CONTROL CENTER provides power to the system loads. These loads may include the motors, circulation pumps, and dehumidification. Signals are

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sent from the various control panels to the motor control center to activate or de-activate the loads. This center may have a series of operations going on simultaneously and may be the “trigger” for other systems.For example, before a chiller can start up, the circulation pumps need to be operating. A signal confirming operation is sent from the motor control center to the starter panel, permitting start up of the chiller.

The MCC is like a large breaker with a bus-like-grid that feeds the power to the individual disconnects or “cans”. The line side of the disconnect will stay hot unless you either de-energize the entire MCC, or pull the entire disconnect from the bus. Since the MCC is controlling a number of different pieces of equipment, de-energizing the MCC is normally never done. Pulling the disconnect represents a number of different hazards since you are pulling it from a live bus. If you do not have a clean pull (removing) or a clean push (installing) you could create an arc. If the equipment is faulty or old, you may snap off the blade that makes contact with the bus, causing an arc. Remember that you want to avoid any practices that could create an arc. When you de-energize the disconnect you should test all “LOAD SIDE” equipment (fuses, transformers, starters, etc.) and verify they are de-energized prior to working on the piece of equipment. Since the MCC is an intertwining of loads, there are multiple relays and power sources. Just because you have locked out one power source does not mean that a second power source is not present. Failure to take this into consideration may cause an electrical shock or arc.

11.6 Disconnect.

DISCONNECTS are devices that manually remove power from a starter or MCC. It may be a circuit breaker, knife switch or some other positive action switch. Disconnects can be designed to remove power from a single component or an entire system. In no case, unless for an emergency, should a disconnect be used as a START/STOP switch. Never shut off a disconnect under load!

11.7 Capacitor.

Locking out a capacitor does not mean that it has been de-energized!

If the capacitor is large enough to have its own disconnect, when you disconnect the capacitor no energy will be allowed to run through the contacts. HOWEVER, if you have to work on the capacitor, it may still be charged!

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You can de-energize a capacitor by using your voltmeter. Take your alligator clip to ground and take your probe to hot. Please make sure you discharge both sides!

NEVER use a screwdriver to discharge a capacitor.

NEVER assume that the capacitor is discharged unless you test it with your meter.

11.8 How to safely shut a disconnect off.

You must always, without exception, shut all disconnects off by standing to the side facing away and, with one swift motion, shut the disconnect to the off position. This way, if something malfunctions you will not be in the way of any flash, blast, and projectiles that will be created by the arc.

When turning a disconnect on or off, always remember to use a swift motion, because if there is a hesitation, the knives or blades may not fully engage or disengage causing an arc. Most disconnects have a spring action device that slams the knives or blades in or out of position.

11.9 Line side and load side.

The area where outside power comes into the panel and connects to the first contact is called the LINE SIDE. The line side will always stay energized unless you go to an outside disconnect and shut it off. When working inside the panel you must always keep this in mind. If you bump the contacts with a screwdriver or metal tool, you may cause an arc!

The voltage coming off the contact is called the LOAD SIDE.

11.10 Single-phase and three-phase.

The difference between single and three-phase is that, for single-phase, only one voltage wave and one current wave exists, which means the AC voltage wave is exactly the same throughout the system. The three-phase system uses three lines called either phase legs or lines. Unlike single-phase systems, the time relationship of the voltage wave in each line differs. The most widely used polyphase system in the United States is the three-phase system.

12.0 MULTIMETER

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The following steps should be followed to verify that your multimeter is properly functioning. We are using the Fluke 87 multimeter for this example; the steps will be the same regardless of the brand of multimeter you use.12.1 These steps should be done prior to using the meter:

Inspect test leads and rubber stops for cracks and tears in the insulation. Only test leads with rubber stops are allowed to be used. The rubber stops help protect your fingers from coming in contact with the circuit.

Plug the black test lead into the common jack Plug the red test lead into the voltage jack Set the function switch to resistance Push the Peak Min/Max button Verify that the test leads have good continuity by touching the tips

together. You should hear a steady beep. Set the function switch to Volts AC

Note: Remember that you must wear safety glasses with side shields and rubber soled work boots when performing work on electrical equipment. Also, never wear jewelry of any kind while working on electrical equipment. This includes large metal belt buckles and tool belts.

Test the meter on a known source. The meter is now ready to be used.

12.2 The following steps should be followed when verifying that an electrical energy source has been deenergized:

We will use a basic three-phase 480 V disconnect as an example.

These steps should be done prior to using the meter:

Inspect test leads and rubber stops for cracks and tears in the insulation. Only test leads with rubber stops are allowed to be used. The rubber stops help protect your fingers from coming in contact with the circuit.

Plug the black test lead into the common jack Plug the red test lead into the voltage jack Set the function switch to resistance Push the Peak Min/Max button

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Verify that the test leads have good continuity by touching the tips together. You should hear a steady beep.

Set the function switch to Volts ACNote: Remember that you must wear safety glasses with side shields and rubber soled work boots when performing work on electrical equipment. Also, never wear jewelry of any kind while working on electrical equipment. This includes large metal belt buckles and tool belts.

Test the meter on a known source. The meter is now ready to be used. Evaluate the work area and equipment that you are going to be

working on. Make sure that there is no water on the floor, equipment is in good condition (no dents, loose controls, etc.) and nothing is on top of the disconnect that could fall and create an arc.

Stand to the side, face away from the disconnect, and with one swift motion snap the disconnect to the off position. Standing to the side carefully open the disconnect and expect the unexpected – wire pops out of the panel when you open the door, someone before you left a tool in the panel, wires are old and the insulation starts to crack and falls apart. NEVER feel complacent when working on electrical equipment.

Evaluate the inside of the cabinet. Verify that everything inside the cabinet is in good working condition. When things do not look right, or you question the integrity of the electrical system that you are working on, STOP and contact someone who will be able to help you. NEVER continue to work on if you are unsure of the equipment.

During the evaluation you also want to examine the disconnect for all incoming power sources. Every disconnect and electrical panel is different and some of them have multiple energy sources! For this example, we examine the disconnect and determine that there is only one power source coming into the cabinet and to the contacts. Remember by turning the disconnect off you only de-energized the load side. This means that the line side will always be energized unless you de-energize the electrical panel that is supplying power to this disconnect.

Change your common probe to an alligator clamp. Using the alligator clamp allows you to place only one hand inside the cabinet. Remember, you never want to have both hands inside the cabinet at the same time. Always make sure that your free hand is not touching a grounded surface.

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Set the function switch to resistance. Push the Peak Min/Max button Verify that the alligator clamp and probe have good continuity by

touching the probe tip to the alligator clamp. You should here a steady beep.

Clip the alligator clamp to the cabinet. You may have to twist the clamp so that it breaks the painted surface and makes contact with the metal.

Verify that the alligator clamp and probe have good continuity by touching the probe to the cabinet. Remember, you may have to push down on the probe to break the painted surface. You should here a steady beep. If you do not hear a steady beep, you will have to adjust the alligator clamp until you do.

Set the function switch to Volts AC, stand to the side of the cabinet and test the load side of the contacts. Test all three phases. The load side is de-energized when you do not get any voltage readings.

Carefully close disconnect and place your lock, hasp and identification tag on the disconnect.

13.0 DETERMINING VOLTAGE

13.1 Power generation.

In fossil-fueled plants, burning coal, oil or natural gas in a boiler produces heat. At nuclear plants, the heat is produced by fission, splitting atoms in nuclear fuel. The nuclear reaction heats water under pressure to prevent it from boiling, much like a pressure cooker. That water is then used to heat another water system that is not under pressure, which boils and produces steam. The steam spins a turbine; the turbine spins a generator filled with magnets and coils of wire, and electricity is produced.

The generator produces the electricity, typically at about 20,000 volts AC. This electrical power is then distributed to a generator transformer, which steps up the voltage to either 230,000 or 345,000 volts. The power is distributed to a switchyard or substation where the power is then sent offsite. Remember that voltage is pressure, so the utility needs to step up the voltage so that it can travel long distances at higher pressure.

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Most utility companies will distribute power to buildings in the range of 13,200 V to 26,400 V. It is then up to the building owner to “transform” this power into usable voltage. This is done by transformers.Voltage is regulated by how the transformer wires are wound. The winding that receives current from the line side is called the primary winding. The winding that delivers current to the load side is called the secondary winding.

The relationship of the primary voltage to the secondary voltage is called the voltage ratio. If one winding has twice as many turns of wire as the other, it will have twice the voltage. When the ratio is given as 10:1, it means that the high-voltage winding contains 10 times as many turns as the low-voltage winding. The higher value in the ratio pertains to the high-voltage winding, and the lower value (often 1) to the low-voltage winding. The ratio of the number of turns of wire in the primary to the number of turns of wire in the secondary is known as the turns ratio.

14.0 Training Requirements

14.1 Safety Training. Employees shall be trained in safety-related work practices and procedural requirements as necessary to provide protection from the electrical hazards associated with their respective job or task assignments. Employees shall be trained to identify and understand the relationship between electrical hazards and possible injury. This training shall be classroom or on-the-job type, or combination of the two. The training shall be documented to reflect date, instructor, and verification of competency. This training shall be conducted before possible exposure to electrical hazards, annually, and additional training when required by the supervisor.

14.2 Emergency Procedure. Employees exposed to shock hazards shall be trained in methods of release of victims from contact with exposed energized electrical conductors or circuit parts. Employees shall be trained in CPR/AED/FA annually.

15.0 Auditing

15.1 Auditing of this program will be conducted annually for verification of compliance and effectiveness.

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Appendix A

University of South Carolina

ENERGIZED ELECTRICAL WORK PERMIT

PART I: TO BE COMPLETED BY THE REQUESTER: Job/Work Order Number ___

(1) Description of circuit/equipment/job location: _____________________________________

_____________________________________________________________________________

(2) Description of work to be done: ________________________________________________

_____________________________________________________________________________

(3) Justification of why the circuit/equipment cannot be de-energized or the work deferred until the next scheduled outage: ________________________________________________________

______________________________________________________________________________

Requester/Sign: ___________________________________________ Date: _____________

PART II: TO BE COMPLETED BY THE ELECTRICALLY QUALIFIED PERSONS DOING THE WORK:

(1) Detailed job description procedure to be used in performing the above detailed work:

______________________________________________________________________________

(2) Description of the Safe Work Practices to be employed:

______________________________________________________________________________

(3) Results of the Shock Hazard Analysis:

______________________________________________________________________________

(4) Determination of Shock Protection Boundaries:

______________________________________________________________________________

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(5) Results of the Arc Flash Hazard Analysis:

______________________________________________________________________________

(6) Determination of the Arc Flash Protection Boundary:

______________________________________________________________________________

(7) Necessary personal protective equipment to safely perform the assigned task:

______________________________________________________________________________

(8) Means employed to restrict the access of unqualified persons from the work area:

______________________________________________________________________________

(9) Evidence of completion of a Job Briefing including discussion of any job-related hazards:

______________________________________________________________________________

(10) Do you agree the above described work can be done safely? Yes No (If no, return to requester)

Electrically Qualified Person(s) _________________________________ Date: _____________

PART III: APPROVAL(S) TO PERFORM THE WORK WHILE ELECTRICALLY ENERGIZED:

_______________________________ ____________________________________Department Manager Maintenance/Engineering ManagerDate: __________________________ Date: _______________________________

_______________________________ ____________________________________Department Safety Manager Electrically Knowledgeable PersonDate: ___________________________ Date: _______________________________

_______________________________ ____________________________________Assistant Department Director Department DirectorDate: _________________________ Date: _______________________________

Note: Once the work is complete, forward this form to the Department Safety for review and retention.

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Appendix B

Job Briefing and Planning Checklist

Identify:

The hazards: ___________________________________________________________________

The voltage levels involved: ______________________________________________________

Skills required: _________________________________________________________________

Any “foreign” (secondary source) voltage source: _____________________________________

Any unusual work conditions: _____________________________________________________

Number of people needed to do the job: _____________________________________________

The shock protection boundaries: __________________________________________________

The available incident energy: _____________________________________________________

Potential for arc flash (conduct an arc flash-hazard analysis): ____________________________

Ask:

Can the equipment be de-energized? ________________________________________________

Are backfeeds of the circuits to be worked on possible? _________________________________

Is a “standby person” required? ____________________________________________________

Check:

Job plans: _____________________________________________________________________

Single-line diagrams and vendor prints: _____________________________________________

Status board: ___________________________________________________________________

Information on plant and vendor resources is up to date: ________________________________

Safety procedures: ______________________________________________________________

Vendor information: _____________________________________________________________

Individuals are familiar with the facility: _____________________________________________

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Know:

What the job is: ________________________________________________________________

Who else needs to know-communicate: _____________________________________________

Who is in charge: _______________________________________________________________

Think:

About the unexpected event…What if? ______________________________________________

Lock-Tag-Try: _________________________________________________________________

Test for voltage-first: ____________________________________________________________

Use the right tools and equipment, including PPE: _____________________________________

Install and remove grounds: _______________________________________________________

Install barriers and barricades: _____________________________________________________

What else? ____________________________________________________________________

Prepare for an Emergency:

Is the standby person CPR trained? _________________________________________________

Is the required emergency equipment available? _______________________________________

Where is it? ___________________________________________________________________

Where is the nearest phone? ______________________________________________________

Where is the fire alarm? __________________________________________________________

Is confined space rescue available? _________________________________________________

What is the exact work location? ___________________________________________________

How is the equipment shut off in an emergency? ______________________________________

What is the emergency phone number? ______________________________________________

Where is the nearest fire extinguisher? ______________________________________________

Are radio communications available? _______________________________________________

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