Electrical Safe Work Practices Objectives (OSHA and NFPA 70E) · (Approach Boundaries- NFPA 70E Table 130.4(D)(a) The restricted approach boundary represents the minimum distance

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Presented byLee Marchessault, CUSP, CUSA

President, WSSI

Electrical Safe Work Practices (OSHA and NFPA 70E)

Objectives

Explain Electrical Hazards Including Shock and Arc Flash.

Describe Approach Boundaries: Restricted, Limited, Arc Flash Protection Boundaries.

Define Training and Qualifications for Electrical Workers.

Demonstrate Personal Protective Equipment.

Describe Safety-Related Work Practices including methods to De-energize, LOTO and Verify by Testing.

Understand Wiring Requirements.

Explain updates to the 2021 NFPA 70E

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Electrical Fatality Statistics

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• All electrically related fatalitiesin 2018 were caused by electric shock, no fatalities were caused by burns.

• 61% of electrical fatalities occurred in workers aged 25 –44.

• 35% of electrical fatalities occurred in Private Residences

• 26% occurred in Industrial Place and Premises

• 13% in Street and Highway.

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Intense Light

Sound Waves

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Pressure Waves

Shrapnel

Hot Air-Rapid Expansion

Molten Metal

Copper Vapor:Solid to VaporExpands by 67,000 times

Electric Arcs can reach the Temperature of the suns

Surface or 35,000°

The box effect makes the arc directional increasing

the flash hazard

Severity depends on the capacity of the arcto deliver enough energy to cause a thermal

burn of greater than 1.2 cal/cm² at 18” (NFPA)

What is an Arc Flash?

Incident energy is measured in calories/cm²The level depends on available bolted fault current,

clearing time, impedance, and distance.

What We Need to Know

Arc

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An arc flash starts from a ground fault or a short circuit.

Ground Fault

ShortCircuit

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Clearing Times of Protective Devices Table 130.7(C)(15)(a)New Note

Device CyclesCurrent Limiting Fuse .5Molded Case Breaker 1.5Insulated Case Breaker 3.0Relay Operated Bkr 1-35 kV 5.0Insul. Case with motor delay 20.0Insul. Case ST Delay no Inst. 30.0

Time Current Curve

Coordination and Short Circuit StudyRequired by OSHA 1910.303(b)(5)

Coordination and Short Circuit StudyRequired by OSHA 1910.303(b)(5)

Incident energy is directly proportional to clearing time

Arc Flash Hazard Assessment

480 volt

Not Enough

AFB 215” 96 cal/cm² @ 18” AFB 55” 18.6 cal/cm²@18”

<18” < 1.8 cal/cm²@18”

AFB < 10” .5 cal/cm²@18”

PPE Cat 4

PPE Cat 2PPE Cat 1

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PPE Cat 3

AFB 33” 7.6 cal/cm²@18”

Improper Wire Protection

Causes of Arc Flash Events

Connections not torqued properly or wired wrong

Insulated Torque wrench and screwdriver

Insulated Torque wrench and screwdriver



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Replacing buckets on MCC (Motor Control Center Improper use of non-insulated tools


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Installation or employee error

Causes of Arc Flash Events Cause of Arc Flash Event

No updated short circuit and coordination study

OSHA 1910.303(b)(4) and (b)(5)

Protective Clothing after a 480 Volt Flash

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Not wearing an arcshield as the hazarddictated. Notice wherethe protection left off.

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Engineer out the arc flash hazards

DuPont electricians fabricated a racking tool reducing worker exposure by distance.

Increasing Distance

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Engineer out the Arc Flash Hazard

By remote switching

By reducing the clearing time

Arc Flash Relay

Differential Relays

Maintenance Switch

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Training

Employees shall be trained in and familiar with the safety-related work practices, safety procedures, and other safety requirements that pertain to their job assignments.

Electrical employees and those responding shall be trained to release victims from contact with exposed electric parts an shall be regularly instructed in CPR.

To be considered a qualified worker training may be in the

Classroom or on-the-job. 19

Qualified Employees

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NFPA 70E 2015 Definitions Qualified person is “One who has

demonstrated skills and knowledge in the construction and operation of electric equipment and installations and the hazards involved”. They shall als be competent and have: Skills to distinguish live parts. Skills to determine nominal voltage Understanding of approach boundaries. Understanding of special precautionary

techniques, PPE, insulated tools, etc.

Unqualified persons not allowed within

limited space

Limited Approach Boundary

Any point on an exposed, energizedelectrical conductor

or circuit path

Restricted Approach Boundary

Shock Boundaries 150-750 V

Qualified workers may enter restricted space only with appropriate

protection12”

42”

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Approach Distances for Qualified Employees(Approach Boundaries- NFPA 70E Table 130.4(D)(a)

The restricted approach boundary represents the minimum distance unprotected skin can be to energized parts [arm’s reach plus…].

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Test to Verify De-energized

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Qualified Employees shall be competent and understand:

• Proper use of special precautionary techniques, PPE, insulating and shielding material, and insulating tools.

Must be Listed

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Special Precautions

Capacitors shall be disconnected and after 5 minutes short circuited.

Consider Gradient Potentials around higher voltages.

Have adequate lighting

No open secondary on CTs

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Personal Protective EquipmentHazard Assessment OSHA Subpart S

Employees working in areas where there are potential electrical hazards shall be provided with, and shall use, electrical protective equipment that is appropriate for the specific parts of the body to be protected and for the work to be performed.

PPE shall be maintained in safe and reliable condition and inspected.

Determine heat level in cal/cm²

AR Clothing has ATPV (Arc Thermal Performance Value) in cal.cm²

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Ugly P. 62

Protection from Shock

Assess for hazards requiring PPE

Inspect before use

Understand how to wear and use PPE

OSHA 1910.135 - ANSI Z89.1 Type I Class E and G

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OSHA 1910.136ASTM F1116-17 20kV

OSHA 1910.137References ASTM stds.

OSHA 1910.133ANSI Z87.1

OSHA 1910.95ANSI S12.42

AR Clothing

AR Clothing has an Arc Rating in cal/cm2. ATPV – Arc Thermal Performance Value

EBT – Energy Break-open Threshold

Determine heat that could be released from an electric arc (incident energy) for the job in cal/cm2.

Wear clothing with Arc Rating greater than incident energy for the job.

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Arc Flash PPE1.2 – 40 cal/cm²

Hard hat with Arc Shield and safety

glasses

FR Pants and Shirt or coveralls over cotton

Cat 2

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Leather BootsShock and Arc Flash

Protection

Balaclava

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Arc Flash Engineering Analysis

Dangerous Arc Flash Level

3516 Generator101 cal/cm² at 18”

2020 NEC

Determine PPE (Labels)

Arc Rating can be for a single layer or a multi-layer system if tested as a combination 35

Determine PPE - Layering

Layered System

Note: For over 12 cal/cm², arc rating can be a multi-layer System if

tested as a combination(shirt, pants, coverall and/or suit)

Summary: Protection for 480 volt 7.6 cal/cm²Personal Protective Equipment:8 cal/cm² pants, long-sleeved 8 cal/cm² shirt (or coveralls), Class 0 or 00 rubber gloves with leather protectors, hard hat with arc balaclava hood and arc-rated face shield min. 8 cal/cm², safety glasses (plastic rims), leather shoes, hearing protection, and for outside work AR winter-wear/rainwear.

Restricted Approach Boundary 12”

Limited Approach Boundary 42”

Flash Hazard Boundary (Calculated)

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Decision-Making Process

Worker shall be able to: Perform the job safely Identify electrical hazards Assess the associated

risks Select appropriate risk

control methods from the hierarchy of controls.

High RiskModerate RiskLow Risk

Assessing the Risk

ATS connected to main bus of 1964 Switchgear

ATS connected to switch Downstream of main switch

of 2004 Switchgear

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Electrical Job Safety Plan

Before starting each job that involves an exposure to electrical hazards, the [qualified] employee-in-charge shall complete a documented job safety plan and conduct a job briefing with the employees involved and include: Job tasks

Electrical hazard

Shock and arc flash risk assessment

Work procedures including special precautions, energy source controls [and PPE requirements]

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Job Briefing

Hazards associated with the job

Work procedures involved

Special precautions

Energy source controls (Lockout/Tagout)

Personal protective equipment

Energized areas in Substations

Emergency Response Procedures

A job briefing shall be conducted and shall cover at least the following subjects:

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Employer Responsibilities

The employer shall determine, through regular supervision or through inspections conducted on at least an annual basis, that each employee is complying with the safety-related work practices required by this standard.

Retraining shall be performed if deficiencies are identified and at intervals not to exceed 3 years.

Electrical Safety Programs is required and must be audited.

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Proper work procedures?

√

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Safety Related Work Practices

Live parts which an employee may be exposed shall be deenergized before an employee works on or near them unless the employer can demonstrate that deenergizing introduces additional or increased hazards. (OSHA)

A qualified person shall use test equipment to test the circuit elements and electrical parts of equipment

and shall verify that the parts are de-energized.Check meter on a live source and calibrate.

Verify De-energized

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Control Hazardous Energy Electrical Lockout/Tagout

Review Drawings/Schematics

Notify and coordinate with others

Barricade the area

Shut equipment down

Apply locks and tags for each (lock box for group LO)

Operate to ensure it is shut off

Test voltage L-D-L (Unqualified verification with controls)

Release stored energy

Return the controls to the off position before removing tags.

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Energy Isolation Devices

Push buttons, selector switches, and other control circuit type devices are not energy isolating devices.

Such controls interrupt power, but do not isolate power.

Effective Breaker LOTO Assess the Risk

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Working on or Near Live Parts

Justification for working on or near unless creates Additional/ increased hazards

Infeasible due to: Interruption of life support

Deactivation of emergency systems

Shutdown of hazardous location ventilation systems

Diagnostic testing/Troubleshooting/startup

Less than 50 volts with parameters

49Energized Work Permit

Energized Electrical Work Permit

Exemptions to permit Testing

Troubleshooting

Voltage measuring

Still need safe work practices

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Working On or Near Live Parts

Inherently self-protected (ohm setting)

Protection from max voltage and impulse value from transients on this UL Cat III / Cat IV device.

Leads double insulated, shrouded and finger guards.

Training mandated.

Check at known source before testing de-energized parts (6,9, or 12 pt. test)

All voltage testers are not equal

Cat III 1000vCat IV 600v

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Test Incident

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2nd degree burns

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Test 4160 Volts with Wiggy

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Grounding Path

The path to ground from circuits, equipment, and enclosures must be permanent, continuous and effective.

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Use caution whenperforming maintenance, a difference

of potential may exist.

Temporary Portable wires

Ground fault circuit interrupter protection should be provided and utilized for all temporary cord and plug activities.

GFCI protection is required for all wet locations

Check ground pins No damaged cords Flex wire not for

permanent wiring56

Visual Inspections

Qualified persons shall visually inspect cord sets, test instruments, leads and equipment. Any defective or damaged item shall be removed from service.

Twist lock connectors must be locked before use.

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Reclosing Circuits After Protective Device Operation

Circuits that are opened by a protective device shall not be manually reenergized until it has been determined that the equipment and circuit can be safely energized.

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Guarding of Live Parts

Must guard live parts of electric equipment operating at 50 volts or more against accidental contact by: Approved cabinets/enclosures Location or permanent partitions

making them accessible only to qualified persons

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• Electrical equipment shall be free from recognized hazards that are likely to cause death or physical harm.

Electrical Equipment

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Before

Work in Workmanlike Manner

After

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Other Hazards

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Same phases wires in one conduitBees

What’s New in the 2021 NFPA 70E

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What’s New in the 2021 NFPA 70E?

Major changes to Article 110: Transferred sections from 120

and 130.

110.1(l)(1) Job Safety Planning: An informational note was added referencing an example of a job safety planning check list in Informative Annex I.

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Article 100 Definitions: Balaclava: The word “hood”

and “sock” were removed, and the definition was changed to: “An arc-rated head-protective fabric that protects the neck and head except for a small portion of the facial area.”

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110.1 Electrically Safe Work Condition: New informational note was added: “An electrically safe work condition is not a procedure, it is a state wherein all hazardous electrical conductors or circuit parts to which a worker might be exposed are maintained in a de-energized state for the purpose of temporarily eliminating electrical hazards for the period of time for which the state is maintained.

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110.3 Electrically Safe Work Condition shifted from Article 130.2 to prioritize and emphasize that de-energizing is a requirement of an Electrical Safety Program and the requirement to de-energize should be located before lockout requirements [ Article 120].

Article 130 now focuses on requirements related to work involving an electrical hazard.

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• 110.2(A)(4) Type of Training: An informational note was added: “Classroom training can include interactive electronic or interactive web-based training components.”

What’s new in NFPA 70E 2021

New Informational Note 110.3(c) “On multi-employer work sites (in all industry sectors), more than one employer can be responsible for identifying hazardous conditions and creating safe work practices.”

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110.4(A) Testing: “Only qualified persons shall perform tasks such as testing, troubleshooting, and voltage measuring on electrical equipment where an electrical hazard exists.” (replaced “operating at voltages equal to or greater than 50 volts).

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New Section110.12 Equipment Use: “Equipment shall be used in accordance with the manufacturer’s instructions.”

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120.2(B) Lockout/Tagout Procedure: The text “The procedure shall meet the requirements of applicable codes, standards, and regulations for lockout and tagging of electrical sources” was added to require that any Article 120 compliant lockout/tagout procedure meet applicable regulations.

120.3(C) Lockout Device: Added language to align with OSHA 1910.333(b)(2)(iii)(E)

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120.4(B) (2) Stored energy (new annex R and section in 360 added for working with Capacitors)

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130.4(B) Estimate of Likelihood and Severity: The following information was inserted to provide clarity and usability by aligning with 130.5: “The estimate of likelihood of occurrence of injury or

damage to health and the potential severity of injury or damage to health shall take into consideration all of the following: (1) The design of the electrical equipment

(2) The electrical equipment operating condition and the condition of maintenance.”

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New

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…you might have a bad maintenance conditionWhat’s new in NFPA 70E 2021

New

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…you might have a bad maintenance condition


New

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…you might have a bad maintenance condition What’s new in NFPA 70E 2021

Table 130.5(C) Estimate of the Likelihood of Occurrence of an Arc Flash Incident for AC and DC Systems: A new task was added as YES for likelihood of an arc flash incident for any condition. “Operation of a CB or switch the first time after installation or completion of maintenance in the equipment.”78

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130.5(G) Incident Energy Analysis Method: Informational Note (e) NEW“The arc rating of outer layers worn over arc-rated clothing as protection from the elements or for other safety purposes, and that are not used as part of a layered system, shall not be required to be equal to or greater than the estimated incident energy exposure.”

Note (d) Footwear other than leather may be used if tested…

79Layered system: shirt, pants, and coveralls 40.9 cal/cm²

FR Vest (OK)


130.7(C)(1) Personal and Other Protective Equipment (C)(1) General: An informational note was added regarding examples of risk-reduction methods that could be used when testing for absence of voltage when the estimated incident energy exposure is greater than the arc rating of commercially available arc-rated PPE.

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Not Enough

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130.7(C)(1) Examples of Risk Reduction Methods Use a non-contact tester before using a

contact test instrument to verify the absence of voltage below 1000 volts.

If the equipment design allows, observe visible gaps between conductors and circuit parts and electrical sources of supply.

Increase working distance.

Table 130.7(C)(7)(a) Maximum Use Voltage for Rubber Insulating Gloves



Article 360 Safety-Related Requirements for Capacitors:

360.1 Scope 360.2 Definitions

360.3 Stored Energy Hazard Thresholds

360.4 Specific Measures for Personnel Safety

360.5 Establishing an Electrically Safe Work Condition for a Capacitor(s)

360.6 Grounding Sticks83

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Informational Annex D.4 IEEE 1584-2018 Calculation Method: This was updated to provide an overview of the new 2018 edition of IEEE 1584.

Annex D: Calculations gone and now references IEEE 1584 std.


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Informative Annex F.7 Battery Risk Assessment: New annex material provides guidance for users on how to select PPE using a battery risk assessment process when multiple hazards are present.

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Informative Annex R Working with Capacitors: This new annex provides additional information regarding capacitors to support the new Section 360.

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Informative Annex R Working with Capacitors: Qualifications and Training

Shock Hazard

Short Circuit Hazard

Internal Rupture

Perform Risk Assessment

Capacitor Stored Energy

Arc Flash Hazard

Determine Arc Blast

Test and Ground Methods87

What’s New in the 2021 NFPA 70E? Can we now…

Explain Electrical Hazards Including Shock and Arc Flash.

Describe Approach Boundaries: Restricted, Limited, Arc Flash Protection Boundaries.

Define Training and Qualifications for Electrical Workers.

Demonstrate Personal Protective Equipment.

Describe Safety-Related Work Practices including methods to De-energize, LOTO and Verify by Testing.

Understand Wiring Requirements.

Explain updates to the 2021 NFPA 70E

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None of us can control the wind, but we all can control the sails.

Choose to be safe!

Questions?Email:[email protected]

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Documents

Electrical Safe Work Practices Objectives (OSHA and NFPA 70E) · (Approach Boundaries- NFPA 70E Table 130.4(D)(a) The restricted approach boundary represents the minimum distance