Professional Arborist Association of Mississippi

Transcription

1 Professional Arborist Association of Mississippi 2015 Annual Conference Electrical Hazards Awareness Program Gary Ickes CTSP, BCMA, TRAQ, MS January 15, 2015

2 Presented by: Gary Ickes January 15, 2015

3 Informs you about hazards when working around energized conductors and how to avoid them Help you meet compliance requirements

4 It is a program, not just a workbook When you enroll you get: 1. An EHAP Training Manual with six chapter tests and verification forms 2. A copy of ANSI Z133.1 safety standards 3. Test correction of each chapter test, including up to three retakes.

5 It is a program, not just a workbook When you enroll you get: 4. Maintenance of transcript in the TCIA database 5. On-demand notification of transcript status via our toll free number 6. A Certificate of completion when you successfully complete the program (NOT CERTIFICATION!)

6 Watch the TCIA videos, Electrical Hazards & Trees & Aerial Rescue-2008 edition (requires documentation) Pass six tests in the training manual (85% or 4 wrong answers or less per most tests) Participate in a practice Aerial Rescue (bucket rescue, climbing or both) following aerial rescue protocol (requires documentation)

7 Obtain CPR/First Aid Certification (If you do not have a current CPR First Aid certification of completion, you will need to take the CPR/First Aid course within 30 days of completing EHAP) Update your training annually.

8 EHAP Refresher Training Initial EHAP Certificate has not expired. Take a refresher test provided by TCIA Certify that employees reviewed the required TCIA video s (Electrical Hazards in Trees/Aerial Rescue 2008 edition).

9 EHAP Refresher Training Certify that employees practice aerial rescue and are trained in Aerial Rescue Protocol Prove employee has a current CPR/First Aid card

10 Requires that the employee maintain a high level of awareness of electrical conductors Helps employees maintain a high level of skill in performing aerial rescue Requires that the employee demonstrate a continuing ability to recognize electrical hardware and hazards

11 Practically speaking:.to provide you with an understanding of the electrical hazards which can exist in the tree care industry To provide you with measures to protect yourself from those hazards.

12 Mark Adams, Adams Arbor Care, LLC, Bugwood.org

13 Understand what it means to be a Qualified Line Clearance Arborist Understand the nature and characteristics electrical hazards.

14 Learn what equipment, tools and procedures will help you avoid the hazard. Learn emergency response/aerial rescue principles.

15 How to use TCIA s EHAP program Risk in the tree care profession OSHA s and ANSI training requirements Basic electrical terminology How electricity works

16 Identifying electrical system components How electricity affects the human body Hazard recognition Hazard Avoidance/Work Practices New aerial rescue protocol

17 95% of our fatalities are in 4 groups! Transportation Electrocution Struck-by s Falls There are other risks as well Courtesy of Dr. John Ball

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19 Of the 19 electrocution accidents: Six victims were electrocuted through conductive tools such as stick saws, pole saws and, in one instance, a rake. Five victims made direct contact with conductors. Two victims on the ground touched uninsulated vehicles.

20 Of the 19 electrocution accidents: In one case, a crane load line made contact with a primary conductor, energizing the ground around the crane. A worker died when he touched a detached chipper 20 feet away from the crane. It could not be determined how five of the victims made contact. Average age of the electrocution victims was 44.

21 Electrical lines are present at almost every jobsite. Direct or indirect contact with these lines can cause shock, electrocution, third and fourth degree burns.

22 OSHA , , Covers workers within 10 feet of any energized electrical conductor during normal tree care operations Requires that employers must document electrical hazard training TCIA s EHAP helps to meet the training documentation requirements

23 TCIA s EHAP course is a six part training program (manual chapters) that focuses on the special hazards associated with performing arboricultural operation around electrical conductors.

24 Completing all six components of this course provides a broad introduction and preparation for the special hazards involved with performing tree work around electrical conductors.

25 The authority and responsibility to certify a worker to work near electrical conductors (<10 feet), is up to the employer. This certification should be in place for all workers before they come within 10 feet of electrical utilities.

26 It is the responsibility of the employer to certify their employees EHAP course completion along with other documented training (ex. Climbing, pruning, rigging, emergency response) is part of the certification requirement On-the-job (OJT) training is also required This is best documented through Competency Checklists

27 The ANSI Z133.1 safety standard for arboricultural operations requires all employees be trained to recognize electrical hazards. EHAP training meets the ANSI Z133.1 training requirement.

28 Electrical Hazard An object or situation that poses risk of injury or death due to direct or indirect contact with an electrical conductor. Where unguarded, energized electrical conductors are present, specific minimum approach distances based on the arborist s or worker s level of training, as set forth in this standard, shall be followed. Traditionally: If a tree, worker or tool will be within 10 of an overhead energized conductor

29 Electrical Hazard Only qualified line-clearance arborists or qualified lineclearance arborist trainees shall be assigned to work where an electrical hazard exists. Qualified line-clearance arborist trainees shall be under the direct supervision of qualified line clearance arborists.

30 Volts (voltage) Electrical pressure which causes current to flow through a conductor Note: 1,000 volts equal one kilovolt (1 kv) Amps (amperes, amperage) The flow rate of an electrical current Ohms (resistance) The measurement of resistance to flow of electricity

31 Maximum Nominal Voltage The greatest potential voltage of a system or circuit based on its design. Energized A line or circuit part having electrical energy present (or possibly present) Contact When a part of the body touches an energized circuit part. Contact can be direct or indirect. It can be phase to ground or phase to phase.

32 Transmission Lines Ultra high voltage lines (usually 100kV-765 kv) that transmit large amounts of electrical energy Sub-transmission Lines Very high voltage lines (typically 27kv-69 kv) running between distribution substations

33 Primary Distribution Lines High voltage lines (usually 2.4 kv-34.5 kv) that run from substations to transformers at houses and businesses Primaries can be single phase or multiple phase Secondary Lines Low voltage lines (typically volts) coming from transformers and running to houses and businesses

34 Generation Plant Generates electricity from coal, gas, nuclear, water fall or other sources Transformer Steps electrical energy from high to low voltage or low to high voltage Automatic Line Recloser Operates like a fuse except that a recloser can automatically restore energy once the overload condition no longer exists

35 Qualified Line Clearance Arborist (QLCA) An individual who, through related training and on the-job experience, is familiar with the equipment and hazards in line clearance and has demonstrated the ability to perform the special techniques involved. This individual may or may not currently be employed by a line-clearance contractor. Qualified Line Clearance Arborist Trainee (QLCAT) An individual undergoing line-clearance training under the direct supervision of a qualified line-clearance arborist. In the course of such training, the trainee becomes familiar with the equipment and hazards in line clearance and demonstrates ability in the performance of the special techniques involved. Minimum Approach Distances MAD The distance required to the conductor beyond the normal reach of the worker, including the reach of any tool or branch

36 It is a form of energy (such as light, heat) It can be transferred by wires It is the flow of electrons Conductors promote this flow while insulators inhibit it Electron flow across the filament of a lamp will produce light

37 Voltage is the electrical potential between two points Each different potential point is called a phase There is a difference in electrical potential between a phase and ground or between one phase and another

38 Current = Voltage/Resistance Current = 120 volts/150 ohms =.8 amps Resistance (150 ohms) Voltage (120 volts) Neutral lead 120 volt hot lead Current flow (amperes)

39 .Electrical energy is constantly seeking a different potential (either another phase or ground potential).if you provide that path, it will flow through you!

40 Distribution Substation. Transformers step voltage from subtransmission levels to distribution levels (usually 2.4kV-34.5kV) Will have large circuit breakers protecting outgoing circuits

41 Primary Distribution Line. Usually on wood poles or buried underground Typically, 2.4 kv-34.5 kv Delivers electricity to individual communities and industry

42 Service Drop. Goes from last pole or transformer into the house or business Usually carries volts Cable, TV and telephone have service drops. Often buried underground

43 The higher the wire = the higher the voltage More insulators = more voltage Larger conductors = higher voltage

44 Three Phase Primary Distribution Line phase primary line 2. Insulator Crossarm 4. Transformer Cutout 6. Lightning arrester 8 7. Neutral 9 8. Street light Cable TV line 10. Telephone line

45 Service Drop

46 POLE IDENTIFICATION NUMBER

47 Current passing through the body can cause electrocution or severe burns. All electrical sensations are potentially fatal!

48 Effects on human health Electrocution = Death 1/10 th of an ampere across the heart can kill Suffocation Blood cell damage Massive trauma, exit wounds, etc. Burns External Internal Broken bones

49 Electrical Burns Entrance Wound: High resistance of skin transforms electrical energy into heat, which produces burns around the entrance point (dark spot in center of wound). This man was lucky, the current narrowly missed his spinal cord. The following 7 slides contain photographs from OSHA s Construction etool web page:

50 Exit Wound: Current flows through the body from the entrance point, until finally exiting where the body is closest to the ground. This foot suffered massive internal injuries, which weren't readily visible, and had to be amputated a few days later.

51 Arc or Flash Burns This man was near a power box when an electrical explosion occurred. Though he did not touch the box, electricity arced through the air and entered his body. The current was drawn to his armpits because perspiration is very conductive.

52 Thermal Contact Burns Current exited this man at his knees, catching his clothing on fire and burning his upper leg.

53 Internal Injuries: This worker was shocked by a tool he was holding. The entrance wound and thermal burns from the overheated tool are apparent

54 Same hand a few days later, when massive subcutaneous tissue damage had caused severe swelling (swelling usually peaks hours after electrical shock). To relieve pressure which would have damaged nerves and blood vessels, the skin on the arm was cut open.

55 Involuntary Muscle Contraction: This worker fell and grabbed a powerline to catch himself. The resulting electric shock mummified his first two fingers, which had to be removed. The acute angle of the wrist was caused by burning of the tendons, which contracted, drawing the hand with them.

56 In addition to either instant death from contact or loss of breath or cardiac arrest, there may also be: Burns, and these are most severe at point of contact with source and ground. Spine injury are a possibility due to forceful muscular contractions. Broken bones can also occur due to muscular contractions. Courtesy of Dr. John Ball

57 Entry and exit burns Visual disturbances Muscle tenderness/twitching Restlessness or irritability Fractured or dislocated bones *Nova Scotia Power

58 Blood pressure changes Loss of consciousness Respiratory distress Irregular heartbeat or cardiac arrest Deep tissue injury; not visible or immediate *Nova Scotia Power

59 Arc flash is a short circuit through the air High voltages can Arc, or jump The greater the voltage, the greater the distance of arc After contact is made, a 1-foot arc can be drawn for every 10,000 volts when trying to break contact

60 Arc flash is a short circuit through the air Temperature of an arc can reach more than 35,000 F (4 times hotter than sun!) A 10,000 A arc at 480 V is equivalent to approximately eight sticks of dynamite. Also potential for eye injury.

61 Step potential occurs when large amounts of electrical energy go to ground and create an uneven ground potential

62 Very small amounts of current can kill! How much is too much? One milliamp is only one-one thousandth of an amp! Many circuit breakers don t open until 15 amps of overcurrent is reached. 1 ma can be felt 3-10 ma, muscle contraction and pain ma is let go threshold ma, respiratory paralysis* ma, heart clamps tight* 1500 ma, tissue and organs burn* *Often fatal Note: Normal skin resistance is around 1000 ohms. Remember, these are milliamperes, not volts!

63 Home Appliances - up to 40 amps Service Lines up to 200 amps 7.2 kv up to 150 amps 14.4/15 kv up to 200 amps 34.5 kv up to 200 amps Remember 0.1 amps can kill! To put it all in perspective, the electric chair runs 2000 volts at 8 amps

64 Site inspection & Job briefing

65 Job Briefing: The communication of at least the following subjects for arboricultural operations: hazards associated with the job work procedures involved special precautions electrical hazards job assignments personal protective equipment. Any new hazard or change in job site needs to be addressed

66 The work must be performed by QLCA s or QLCAT s There must be another qualified person within voice or visual communication if working aloft

67 All tree workers must inspect any tree to be worked on to determine if an electrical hazard exists. A thorough investigation of the entire worksite to locate hazards and the formulation of a plan to mitigate these hazards must be done prior to working.

68 Tree Inspections Look for electrical hazards first Inspect the tree in a systematic, consistent way Roots, soil, base of tree Trunk, major branches Crown walk around

69 Electrical Hazards All conductors must be considered energized with potentially fatal voltages! Consider the potential for tree defects to cause contact with conductors. Defective parts could dislodge during climbing or rigging Consider adjacent trees as well

70 Electrical Hazards Look for other hazards created by your work: Branches that could contact conductors if weight is applied to them during climbing/rigging Look for branches, leaders, whole trees that might become a hazard during the removal process Understand how forces involved in rigging can cause trees or portions of trees to fail and possibly contact energized conductors

71 Electrical Hazards Under storm or other emergency situations the following are potential conductors of primary voltages: Guy wires Metal fences Street light poles Communication lines Highway guardrails, road striping Woody vines and other vegetation

72 Electrical Hazards Trees that are or have been in contact with conductors will show signs: Branches contacting conductors Burned or damaged leaves Witches brooms Notched, burned branches

73 How are voltages determined? Only a circuit map or voltage meter can accurately and reliably indicate the actual voltage Maximum Nominal (potential) Voltage can be determined Based on construction, location of wires, number and types of insulators, etc.

74 General rules about determining voltage: Highest voltages are usually at the top of the pole Communication lines are usually at the bottom, but still carry potentially fatal voltages Larger and more numerous insulators indicate higher voltages Taller poles indicate higher voltages Greater conductor separation indicates higher voltages

75 Never work near electrical conductors unless: You are trained and qualified to do so You understand exactly what you need to do You know the maximum nominal voltage and MAD You plan to use methods to reduce the danger of the electrical hazard You are positive that the job can be done safely

76 QLCA must be able to recognize the maximum nominal phase to phase voltage in a given conductor and plan work accordingly Voltage estimate is needed to determine the Minimum Approach Distance (MAD)

77 Minimum Approach Distance (MAD) Refers to the space between the person (including the longest conductive object he or she may contact) and any unguarded, energized overhead line. Also applies to vehicles All electrical sensations (potentially fatal contacts with electricity) happen because a worker violated MAD!

78 Courtesy of the Lucas Tree Expert Company

79 Courtesy of the Lucas Tree Expert Company

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81 (q)(1)(i) Employees engaged in pruning, trimming, removing, or clearing trees from lines shall be required to consider all overhead and underground electrical power conductors to be energized with potentially fatal voltages, never to be touched (contacted) either directly or indirectly.

82 Section 420. B.1. Employees whose duties require working on or in the vicinity of energized equipment or lines shall perform only those tasks for which they are trained, equipped, authorized, and so directed Translation: We work around the lines, not on them.

83 Some telecommunication lines are listed as carrying 48 volts 50 volts is threshold for OSHA NIOSH says 49 volts can be fatal Some lines can carry up to 120 volts We have no way of knowing what voltages are in the lines Phone company employees have told tree workers to move or cut phone lines Risk of eye damage if fiber optic lines are broken Bigger issue, more to come

84 It is a Federal crime to cut phone lines.

85 If you can not do the job safely while maintaining your MAD: Do not do the job! Contact the utility they have to make it safe via DIG: De-energize Isolate Ground What about covering the lines? Can I get closer than my MAD then? NO!

86 1. Storm knocks out electricity. 2. Homeowner connects generator directly into house wiring without isolating it from in-coming lines. 3. Electricity from generator back-feeds through house wiring breaker box, meter, house drop and transformer. 4. Transformer that usually steps 7,200 volts down to 120 volts steps up 120 volts from generator to 7,200 volts sending it into storm-damaged distribution circuit. 5. Unsuspecting arborist contacts line and is electrocuted!

87 Call the national 811 line Directed to your local utility locating service Required by law in most jurisdictions whenever you go underground Similar to other X11 call services

88 Tree pruning Tree removal Cabling and bracing Lightning protection Pesticide Applications Tree planting/transplanting Stump grinding

89 Only work in proximity to electrical hazards if you have been properly trained and are certified by your employer to do so Respect Minimum Approach distances Maintain tools and equipment Improve cutting and rigging techniques

90 Coating on wires is weather proofing, not insulation Designed to protect the wire, not you Never touch any electrical conductor, apparatus or any conductive object in contact with an electrical conductor

91 Know the utility s policy and practice. You must notify the utility company whenever you will be working within 10 feet of electrical wires. Do this ahead of time. Exception: when you are clearing lines for that utility.

92 Tools and Personal Protective Equipment (PPE) Work Practices

93 Weather and Storm Damage Work prohibited during storms Thorough jobsite inspection necessary Treat all downed lines as energized Fences, gutters, anything conductive can be hot Beware of generator feedback

94 Climbing Procedures Planning to climb: perform complete hazard analysis before entering, climbing or working in any tree. Only QLCA s can work when electrical hazard present Locate all wires first Plan climbing route before leaving the ground Climb on the side away from the wires Select tie-in point so that if you slip you will swing away from the conductors

95 Maintain complete control of limbs near conductors Never allow anything you are holding to contact an energized conductor When cutting limbs above lines, make sure to cut them small enough to pass between the conductors A limb contacting two conductors can cause a fault, or dangerous electric arc

96 Rigging Methods Install rigging line above limb to be removed Pull limbs up or to the side of the lines Additional rigging may be required

97 Aerial Lift Work Minimum Approach Distance Maneuvering lift around conductors Ground personnel safety

98 Courtesy of Man Lift Mfg Co.

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100 Aerial lifts must be: Tested Inspected Cleaned Properly maintained

101 Always know where the conductors are Face the direction of bucket travel Do not work with your back to the conductors NEVER move the bucket between two conductors Inspect and maintain the bucket Insulating parts should be cleaned with non-filming agents Never drill holes in the bottom of the bucket, if water can drain out, electricity can get in!

102 The bucket, boom, tools, and the operator shall never contact the conductors or violate the MAD The truck and any attached equipment shall be considered energized if contact is made If a worker on the ground contacts an energized vehicle, electrocution may occur

103 Bucket Operator Warnings The bucket does not keep you free from risk of electrocution Insulation provides only a measure of safety You can be electrocuted through other paths to ground: If you contact the conductor and the tree at the same time If you contact two conductors at the same time

104 Tools and Equipment Climbing Equipment and Handheld Tools Keep tools clean and dry and in good condition Damaged, dirty, or wet tools conduct electricity Do not use conductive tools near lines Avoid the use of extension cords near lines

105 New Industry Protocol

106 Throw out what you were taught. No more approaching energized trucks or trees No more focus on yanking people down in 4 minutes In brief, we are now focusing on everyone s safety, not just the injured worker

107 The standard for practice and training are as follows: Performed from a height of 35 feet (the height of the typical distribution line). The victim must be on the ground in 4 minutes. This assumes the victim is suffering from electrical shock a rarity in the tree care industry for rescue. This comes from OSHA requirements for Line Clearance Arborists Courtesy of Dr. John Ball

108 Types of Aerial Rescue Scenarios Trapped/Pinned/Entangled Unable to perform self rescue Fall within tree Electrical hazard Struck-by Incapacitated Bleeding Unconscious

109 More accidents and fatalities have occurred during aerial rescue practice, demonstration and competition than any other aspect of arborist training. Accidents have occurred when the rescuer has had their Prusik lock open (pushed too close to the branch the double line was suspended from) or disconnected their own line by error.

110 Courtesy of Tim Walsh The first rule of first aid is to not become the second victim The second rule of first aid is not to move the victim unless there is an immediate need. In most instances of aerial accidents this need does not exist and we can cause further injury by quickly moving the victim. But nor can we allow the victim to remain suspended from their harness. Suspension trauma can occur when the victim is suspended with the legs hanging down blood flow problems. The victim should not be laid horizontal.

111 Incident assessment Assess the victim s condition from the ground. Is this rescue or recovery? Assess your rescue capability Requesting assistance Contact fire & rescue You may have to contact the utility if EMS does not Initiating the rescue Do not attempt if an electrical hazard exists Otherwise ascend to victim, assess condition and secure in a horizontal position. Victim extraction Unless CPR is required (or uncontrolled bleeding) do not extract victim until Fire & Rescue arrive and then do so under their direction. Courtesy of Dr. John Ball

112 Aerial lift evacuation In case of emergency, the operator must know how to descend from the bucket. Aerial lift rescues Do not approach an energized vehicle! Do not pull a victim from a bucket unless they require CPR! Leave them in the bucket until help arrives. If this is not possible, the victim can be tipped out by driving the basket into the ground breaking the leveling cables.

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114 Plan every job as if you will need to perform an aerial rescue.

115 Assess and Evaluate every situation is different No hurry if breathing and not bleeding 911 describe situation for emergency responders Make sure you tell them it is a High Angle Rescue How high and where Access to accident scene

116 1. Assess the situation-every one is different What needs to be done Can it be done safely 2. Who is around to help 3. Call 911 (if some else calls, have them report back to you that they did so) Name, location, nature of injury Don t Hang Up First 4. What is the cause of the injury Is there an immediate threat to you or others CAN YOU HANDLE IT!

117 Dominion Virginia Power & Newport News TV Arc Demo Safety Trailer Presentation

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119 Tree Care Industry Association Web:

120 Gary Ickes I.S.A. Board Certified Master Arborist SO-2919BM TCIA Certified Treecare Safety Professional #497 Ickes Tree Service, Inc