5/5/2016
Arc Flash Assessments
NFPA 70
How it affects the Maintenance and
the Safety Professional
Arc Flash Assessments
NFPA 70
Does NFPA 70, specifically Arc Flash, belong to the
Maintenance Team or the Safety Team?
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Arc Flash Assessments
NFPA 70
To Understand:
What is An Arc Flash
Why OSHA Is Addressing This Issue
Requirements In NEC & NFPA 70E
Impact to Industry
Benefits to completing an Arc-Flash Assessment
What is an Arc Flash
An Arc Flash is a Sudden
Release of Heat and
Energy Caused By An
Electric Arc, an Additional
Hazard beyond Shock
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What is an Arc Flash
Every Day 7 - 10
Electricians are
Severely Injured by
an Arc Flash Event
Effects of an Arc Flash
Arcing faults in power distribution can produce
intense heat
- Texas in August:
105 F
- Surface of the sun: 8,540 F
- Arc (at mid-point): 22,940 F
- Arc (at terminals): 35,540 F
Injuries from arc flash refer almost exclusively to the
effects of burns received
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Effects of an Arc Flash (Cont’d)
Arc Blast
- 6,000 lbs. force won worker’s chest
from moderate fault at MCC
- Pressure can cause collapsed lungs,
concussion, etc.
Molten copper – Vaporized copper expands
40,000x upon vaporization
Shrapnel – Arc Blast can create projectiles that
cause injury
2nd & 3rd Degree Burns
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Potential Causes of Arc Flash
Accidental Contact
- Misplaced tools
- Voltage testers
Equipment Failures
Rodents
Unsuccessful short-circuit interruptions
Racking a breaker on an energized bus
Removing covers
Voltage checks or troubleshooting
NIOSH Arc Flash Statistics
2004 - 2014
85% Industrial Facilities
9% Medical and Institutional Facilities
4% Commercial Facilities
2% Retail
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OSHA REQUIREMENTS
(WHAT)
OSHA 29 CFR 1910.132(d)
requires employers
to assess the workplace to determine if hazards are or
could be present, provide the appropriate PPE for each
affected employee, and requires its use. It also requires
employers to inform the affected employees
regarding hazards and PPE and to verify that the required
assessment was performed through a written certification
identifying the workplace evaluated.
OSHA has determined 50-volts to ground is an electrical
hazard
OSHA REQUIREMENTS
OSHA 29 CFR 1910.133 requires employees who are
exposed to electrical shock and arc hazards to be qualified for
the specific task they are performing. This involves safe work
practices as well as using the appropriate PPE (TRAINING)
OSHA 29 CFR 1910.335 (a)(1)(I) requires employees
working with potential electrical hazards to be provided with,
and use electrical PPE appropriate for the specific parts of the
body to be protected and for the work to be performed.
(POLICIES)
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OSHA Requirements
(How)
NFPA 70E and NEC were written at OHSA’s request to
help employers meet the content of OSHA 1910
Subpart S.
NFPA Became the Standard for Electrical Safety in the
Workplaces – August 2007
OSHA REQUIREMENTS
Effective August 2007 CFR 1910 will be revised that will
mandate Compliance with NFPA 70E-2000 and NEC2002.
SUMMARY: The Occupational Safety and Health Administration (OSHA) is revising the
general industry electrical installation standard found in Subpart S of 29 CFR Part
1910. The Agency has determined that electrical hazards in the workplace pose a
significant risk of injury or death to employees, and that the requirements in the
revised standard, which draw heavily from the 2000 edition of the National Fire
Protection Association's (NFPA) Electrical Safety Requirements for Employee
Workplaces (NFPA 70E), and the 2002 edition of the National Electrical Code (NEC),
are reasonably necessary to provide protection from these hazards. This final rule
focuses on safety in the design and installation of electric equipment in the
workplace. This revision will provide the first update of the installation requirements
in the general industry electrical installation standard since 1981. OSHA is also
replacing the reference to the 1971 NEC in the mandatory appendix to the general
industry powered platform standard found in Subpart F of 29 CFR Part 1910 with a
reference to OSHA's electrical installation standard.
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NFPA70E Article110.1
The employer shall implement an overall electrical safety
program that directs activity appropriate to the voltage , energy
level and circuit conditions.
Other elements of an Electrical Safety Program should include:
a) Awareness and Self-Discipline
b) Electrical Safety Principles (Annex E)
c) Electrical Safety Program Controls
d) Electrical Procedures
e) Hazard/Risk Evaluation Procedure
NFPA70E Articles 120 and 130
(Cont’d)
Deals with establishing an Electrically Safe Work
Condition
Each employee should be trained in Lockout/Tagout
Procedures
The Employer is responsible for the procedures
Simple Lockouts vs. Complex Lockouts
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Electrical Hazards
There are many hazards with electricity. Some of them are
common knowledge and some we have just recently began to
understand:
Shock Hazard – This is the most common thought of hazard
to electricity This hazard produces the most injuries and
fatalities.
Arc-Flash Hazard – This is the least known about hazard.
This hazard can cause severe and fatal burns. The extreme
heat (35,000 F) of an Arc-Flash can ignite clothing, create blast
shrapnel, and dangerous pressure wave. The latest NEC and
NFPA publications now have regulations to minimize the
results of such a dangerous hazard.
Personal Protective Equipment
Voltage Rated Gloves Are REQUIRED for All
Voltage Testing Above 50 Volts
500 V
1000 V
7500 V
17000 V
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Personal Protective Equipment
Must be air tested daily
before usage.
Must be electrically tested
every 6 months or
replaced.
Before issuance gloves
may be stored for up to 1
year without being tested.
OSHA Requirements
(How)
NFPA 70E-2015 Article 130.5 states an arc flash risk
assessment shall be performed and shall
(1) Determine if an arc flash hazard exist. If an arc flash exist
the risk assessment shall determine:
(a) Appropriate related safe work practices
(b) The arc flash boundary
(c) The PPE to be used within the arc flash hazard
boundary.
NEC 110.16 States Equipment must be marked to warn
qualified persons of potential electrical arc flash hazards.
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OSHA Requirements
(How) Cont’d
NFPA 70E 2015 130.5(D) States serviceable equipment shall
be marked with a label containing all of the following
information:
1.Nominal Voltage
2.Arc Flash Boundary
3.At least one of the following:
(a) Available incident energy and corresponding working
distance, or arc flash PPE category but NOT BOTH.
(b) Minimum arc rating of clothing
(c) Site-specific level of PPE
OSHA Requirements
(How) Cont’d
NFPA 70E 2015 130.5 (C) states there are two methods
to determine the required arc flash PPE
1. Incident Energy Analysis Method - IEEE 1584 Methodology to complete the arc flash calculations
2. Arc Flash PPE Categories Method – Task Dependent
Table 130.7(C)(15) – AC Voltages
You cannot mix the two methods
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OSHA Requirements
(How) Cont’d
Table Method
Task Dependent
There is no Category 0 Arc Flash PPE must always be
worn.
User must be familiar with the Electrical System to
be determine Fault Currents and OCP Device
Clearing Times.
Table Method Cont’d
TASK
ARC FLASH PPE REQUIRED
Normal Operation of Switches*
NO
AC Systems Including voltage measurements
YES
Removal of Bolted Covers or Panel Covers*
YES
Removal of CB’s or Switches
YES
Reading of Panel Meters
NO
Preform Infrared Thermography*
NO
Work on Control Circuit 120V and less*
NO
Work on Systems with > 120V
YES
Work on Equipment fed from starters or Electrical Panels
YES
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Incident Energy Analysis Method Table H.3(b)
IEEE 1584 - states systems operating less than 240-volts fed by a transformer
< 125 KVA and has a secondary fault current < 10,000-amps does not pose an Arc Flash
Hazard
Incident Energy Valve
< 1.2 Cal/cm2
Required Arc Flash PPE
Protective clothing, non-melting or untreated cotton, long
sleeves, Safety Glasses, Hearing Protection
>1.2 Cal/cm2 – 12 Cal/cm2
Arc Rated Clothing, Arc Rated Face Shield, Balaclava,
Safety Glasses, Hearing Protection
> 12 Cal/cm2
Arc Rated Clothing Arc Rated Hood, Safety Glasses,
Hearing Protection
NFPA 70E does not recognize
incident energy levels greater
than 40 cal/cm2. This is a very
dangerous condition. No work
should be completed on or near
this equipment.
PPE Examples
< 1.2 cal/cm2
> 1.2 - 12 cal/cm2
> 12 cal/cm2
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OSHA Methods of Enforcement
The General Duty Clause – Requires workplaces to be free
from recognized hazards (shock, electrical burn)
The General Duty clause also requires employees to comply
rules pursuant to the act
The Specific Duty Clause – Requires the employer to comply
with OSHA standards
OSHA’s Use of NFPA 70E
General Duty Clause
- Employer must provide a safe work place
- 70E is considered and “Industry Best Practice”
- 70E is a consensus ANSI standard
Specific Duty Clause
- Employer must follow specific OSHA rules
- OSHA may refer to specific provisions of 70E
Historically, NFPA 70E has been cited for
“Remediation or “Abatement
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Definition Qualified Person
Qualified Person: “One who has received training in and has
demonstrated skills and knowledge in the construction and
operation of electrical equipment and installations and has
received safety training to identify and avoid the hazards
involved.”
How to Be Compliant
Turn it off!!!! OSHA expects it to be locked and tagged
before any work begins.
OSHA 1910.133 states “Live parts to which an employee may
be exposed shall be de-energized before the employee
works on or near them.”
Exception:
Unless de-energization creates a greater hazard or introduces a
additional hazard or is infeasible
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How to Be Compliant
Train your employees
Electrical Workers must meet the OHSA’s definition
of qualified.
Skills and knowledge, safety training, the use of PPE
Conduct job briefings (toolbox meetings)
How to Be Compliant
Assess the Hazards
OSHA 1910.132 (d)(1) states “The employer shall
assess the workplace to determine if hazards are
present, or likely to be present, which necessitate
the use of PPE. If such hazards are present, or likely
to be present, the employer shall Select and have
each affected employee use, the types of PPE that
will protect the affected employee from the hazards
identified in the hazard assessment.”
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Arc Flash Analysis Benefits
•Anticipated Benefits:
•Employee Safety – Primarily improving associate and
contractor safety while interacting with electrical systems,
this includes:
•Reducing the exposure from arc flash
•Matching the PPE requirements to the need, thus reducing
PPE cost
•Establish a means to properly label and rate over current
protection.
•Potentially lowers insurance premiums
• Enables easy changes and upgrades
• Drastically lessens your chances of having to make a very
unpleasant visit to survivors
Arc Flash Analysis Benefits
•System Reliability:
•Improve system capabilities and overall system balance, again
improving up time and performance.
•Allows Reliability community to focus predictive/preventive
resources more effectively, thus improving TRS.
•Asset Conservation: Improved reliability of the system reduces
the probability of significant fire events and resulting property
damage and business interruption.
•Transfer of Best Practice:
•System design features
•System maintenance approaches
•Over current and grounding strategies
•Employee training and overall competence
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Final Thought
WHEN YOU THINK YOU HAVE THIS ELECTRICAL SAFETY
PROBLEM LICKED, YOU WILL BE IN YOUR MOST
VULERNABLE POSITION.
YOU START TO LET YOUR GUARD DOWN. ELECTRICITY
IS VERY PATIENT AND WILL WAIT A LONG, LONG TIME
FOR SOMEONE TO LET THEIR GUARD DOWN, AND IT
WILL STRIKE SWIFTLY AND WITH NO WARNING.
YOU MUST NEVER THINK YOU HAVE FINISHED YOUR
WORK ON ELECTRICAL SAFETY
Thomas D. Sterner
May 19, 1988
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