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Class Objectives

EHS-268 • You will be able to:

– Define the scope of your work, the hazards
and the controls, in terms of NFPA 70E in
Intro to NFPA 70E order to write an accurate AHD for yourself
yourself.
Specifically,
“Standard For Electrical Safety In The • Recognize hazards of electricity
• Describe the purpose of NFPA 70E and its
Workplace”
relationship with OSHA and LBNL
• Describe primary protection from hazards of
electricity
Keith Gershon, EHS Electrical Safety Engineer

Class Objectives What this course is NOT

• You will be able to: • This class is NOT “Qualified Worker”
– Apply safe work condition requirements training
– What is a Qualified Person? Look it up now
– Apply written work permit requirements i NFPA 70E!
in
• Qualified Person, Art 100 & 110.6(D)(1)
– Evaluate shock and arc flash protection • This class does not teach specific skills
boundaries
or safety techniques to qualify you as an
electrical worker. You will demonstrate
– Describe correct selection and use of
electrical PPE these skills as part of your AHD.

Hazards of Electricity Hazards of Electricity – Shock/Electrocution

• 9-16mA = Let go threshold (“hung up”)
• Shock  Invasive current exceeds the body’s
ability to control voluntary and
– Direct/Indirect autonomic processes. Current Effect
 Break contact 1mA Barely perceptible
– Electrocution • 16-30mA = Highly Dangerous 1-5mA Perception threshold
 Cardiac and biological issues
• Burns  Internal tissue heating 5-9mA Painful sensations (involuntary
reactions)
• 30-100mA = Fatal Exposure
• Arc Flash/Blast  Respiratory paralysis 9-16mA Muscular contraction (can’t let go)

 Cardiac fibrillation 16-30mA Biological issues (internal heating)

• Fire  Internal burns 30-100mA Respiratory paralysis
Ventricular fibrillation
• Factors:
• Explosions  Skin resistance
Tissue burning

 Path
 Physiological diversity

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Hazards of Electricity – Burns Hazards of Electricity – Arc Flash/Blast

• Burns can result
Molten Metal
when a person 35,000 °F
contacts energized Pressure Waves
parts resulting in
current through Sound Waves
body parts.
• Electrical burns of
Shrapnel
this type usually Copper Vapor:
Solid to Vapor
require specialized Expands by
Hot Air-Rapid Expansion
burn treatment and 67,000 times
result in loss of
Intense Light
body parts.

What is NFPA 70E?

NFPA 70E and OSHA • First released in 1979 to address those
electrical safety requirements necessary
for the practical safeguarding of
employees in their pursuit of gainful
employment.
NFPA 70E andd OSHA’
OSHA’s SSafety-Related
f t R l t d
• Made up of three chapters; Chap 1,
Work Practices requirements are to Safety-Related Work Practices, Chap 2,
protect you from these hazards. Safety-Related Maintenance, Chap 3,
Safety for Special Equipment.

• One constant focus…safety of

employees at work as relates to
exposure to electrical hazards.

Do We Have To Do It ?
NFPA 70E and OSHA
• Legal Status of NFPA 70E:
–Not adopted by OSHA
–Not adopted by CalOSHA
NFPA 70E iis a “h
“how tto comply”
l ” standard
t d d ffor
Enforceable through OSHA OSHA electrical regulations.
“General Duty Clause”
• Part of 10CFR 851, therefore mandatory
for LBNL

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OSHA & NFPA What’s in it ?

How Do They
Work Together: • Chapter 1: Safety–Related Work Practices
“It certainly seems to me that if
I’m an employer, and I want to comply • Chapter 2: Safety-Related Maintenance
with a general requirement for
protecting
t ti my employees
l from
f electric
l ti
equ e e ts
Requirements
shock and electric arc, that the
first place I’m going to look is
NFPA 70E.” • Chapter 3: Safety Requirements For Special
David Wallis Equipment
OSHA Director
IEEE Interview
This course focuses on Chapter One.

What’s in it ?
Electrically Safe Work Condition
• Most of what is unique to NFPA 70E is found (130.1)
in Chapter 1: Safety–Related Work Practices. •Most electrical work is required to be done in an
– Qualified versus Unqualified Persons Electrically Safe Work Condition
– Training
– Electrical Safety Program
•NO EXPOSURES!
– Hazard Analyses for Shock and Flash
– Lockout/Tagout
•Electrically Safe Work Condition = LOTO
– Energized Electrical Work Permits
– Approach Boundaries and PPE.
•Follow LBNL LOTO; 70E LOTO is not as
stringent

WHY is LOTO done?

REMEMBER!
• LOTO is done to protect someone who
PPE is your last resort! is working on equipment from being
exposed to an unintended restart of the
equipment
i t or a h
hazard
d ffrom an energy
Deenergized work is your priority!
source.
– The purpose of LOTO is to prevent
Ask yourself… accidents that are caused by energy
Have I analyzed this hazard? release.

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WHO MUST PERFORM LOTO? Who Is Authorized To Perform Lockout/Tagout?

To perform LOTO you must:
• EACH WORKER who is working on the
1. Have received LOTO classroom training
equipment must have a lock on the equipment:
(EHS 256). Task and equipment specific,
additional on-the-job training is required;
and
2. Be specifically authorized by your divisional
1 Lock + 1 Key = 1 Protected Worker
line management (supervisor, etc.) to
You do not lock for anybody else; perform LOTO procedures.
Nobody locks for you These qualifications = Authorized Employee
Retraining will be required through course EHS 258 every two years

Electrically Safe Work Condition What does this instrument indicate?

• NFPA 70E provides 6 basic steps for

establishing:

The presence of AC
voltage!

Can I use a proximity style tester for Zero

Energy Verification under LOTO?

No. A qualified
No
person must use
a multi-meter to
verify the
absence of
voltage.
Cannot be accomplished with this device!

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Exception These are the only times a worker may

be exposed to live parts
• High Voltage Equipment
1. De-energizing introduces additional or
– A qualified person may be approved to
use grounding methods in combination increased hazards
with other confirmation methods to OR
assure a deenergized condition on high 2. De-energizing is infeasible due to
voltage equipment (see p.22)
equipment design or operational
limitations

1. De-energizing introduces additional 2. De-energizing is infeasible due to

or increased hazards equipment design or operational
limitations
• For Example,
– Life support
pp equipment
q p • Diagnostics,
g , testing,
g, measuring g
– Emergency alarm systems • Work on a circuit that is part of a large
– Ventilation equipment for hazardous gases continuous process that would need to
be completely shut down

What NOT to do
infeasible
adj : not capable of being carried out or put into
practice
• Analyze the work package
inconvenient
• Figure out how to do it safely
adj : not suited to your comfort, purpose or needs • Put on PPE
“inconvenient cannot serve to • Go to work
justify work on or near exposed
live parts”
- NFPA 70E Handbook
It is important to understand: We are not managing
accidents…WE ARE MANAGING EXPOSURES!

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Energized Work Permit Energized Work Permit

If the equipment is not placed in Testing/Troubleshooting does
an electrically safe work not require a permit, but a
condition, a written permit is completed and authorized AHD
required is required

Energized Work Permit

forms are found in
Appendixes A and B of
Pub 3000

Testing/Troubleshooting/Inspecting does not require written

permit, IF it is covered in your AHD!

Job Briefing Checklist

REMEMBER!
Even if an energized work permit is not
required, and you have a completed and
authorized AHD
AHD, all the safe work A Job Briefing Checklist
is found in Appendix C
practices (which may include work zones
of Pub 3000
and PPE) are still required!

REMEMBER!

Quiz on 130.1 If energized work is justified, the task must be

analyzed before work can be performed!

AHD

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Shock Boundaries

SHOCK Approach Boundaries

130.2 Approach Boundaries to Live Parts • Outer boundary

for work being done under a permit, or for shock
testing / troubleshooting protection
• Unqualified
persons may not
Shock Protection Boundaries cross unescorted
Flash Protection Boundary • Escort must be a
qualified person

Shock Boundaries Shock Boundaries

Restricted Approach Boundary How close can the qualified person work?
Prohibited Approach Boundary
• Qualified persons
• Appropriate PPE may work up to
required the Prohibited
• Qualified persons Approach
have no additional B
Boundary
d
restrictions. • Requires work
• Unqualified persons plan, voltage-
may never cross rated gloves,
Restricted Approach insulated tools
Boundary and possibly
more.

Shock Boundaries Shock Boundaries

Prohibited Approach Boundary - SHOCK Approach Boundaries for Shock Protection

• Working within the

prohibited approach
boundary is the equivalent
of performing live-line
What are your approach
work. distances?
• Requires written work plan
approved by management. NFPA 70E, Table 130.2(C)

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PPE :
Shock Protection

Gloves come in various voltage classes, types,

sizes and colors

Leather Protectors
• Rubber insulating gloves must be used with
leather protectors to prevent damage
• Exception:
– Gloves may be used without protectors if the
work k requires
i unusuall d
dexterity,
t it and d the
th workk
will not damage the glove.
– If protectors are not used, derate glove by one
class.
– Derate 00 gloves are to 250V
• Gloves that have been used without
protectors must remain derated, and shall not
be used with protectors until given an
inspection and electrical retest.

Hazards of Electricity – Arc Flash/Blast

Molten Metal
35,000 °F

Pressure Waves
Exercise II - Shock Boundaries
Sound Waves

Copper Vapor: Shrapnel

Solid to Vapor
Expands by
67,000 times Hot Air-Rapid Expansion

Intense Light

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Flash Protection Boundary

Hazards of Electricity – Arc Flash/Blast Flash Protection Boundary
• The point at which
The energy expelled during an arc-flash/blast is known as the incident energy
“incident energy”. drops to 1.2 cal/cm2.

Thee heat
ea gegenerated
e a ed by the
e
“incident energy” is measured in
calories-per-square-centimeter
(cal/cm2).

1.2 cal/cm2 is the on-set of a second-degree burn. Holding

your finger in the flame of a lighter for 1 second is the
The Flash Protection Boundary may be LESS than the Shock Protection
equivalent of 1 cal/cm2. Boundary…

Flash Protection Boundary Flash Protection Boundary

Flash Protection Boundary

The Flash Protection

Boundary and PPE Level are
determined by the calculations
of a Flash Hazard Analysis.

If your equipment does not have

an arc flash hazard label, it is
acceptable to acquire the
information on the closest
upstream panel, provided there is
no transformer in between.

…or could be GREATER

Flash Protection Boundary Work Zone

If the Flash Protection Boundary is not calculated, it Established to
will usually be 4’ indicate either
Limited Approach
Boundary or
Fl h P
Flash Protection
t ti
Boundary and
protect
unqualified
employees

…but do not ASSUME 4’!

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Flash Hazard Analysis NFPA 70E and OSHA

• Required when work is done inside the OSHA :
Flash Boundary 29 CFR 1910.132(d) Personal Protective Equipment
(1) Hazard Assessment and PPE
• Documented
The employer shall assess the workplace to determine if hazards
• FR Clothing and other PPE must be are present, or likely to be present, which necessitate PPE.
used to protect against the incident
energy 29 CFR 1910.335(a) Use of protective equipment
Personal protective equipment
(i) Employees working in areas where there are potential
Alternative Method: Use table 130.7(C)(9) in 70E to determine the electrical hazards shall be provided with, and shall use,
Hazard/Risk Category based on the task. From the Hazard/Risk electrical protective equipment that is appropriate for the specific
Category the appropriate PPE shall be selected using 130.7(C)(10). parts of the body……..

PPE :
Personal Protective Equipment (PPE)
1.2 Cal 1.3-8 Cal 8.1-25 Cal 25.1-40 Cal

• Insulated gloves/leathers
• Hard hats
• Face Shields/Flash Hoods
• FR Clothing
• Insulated tools

Hazard Risk Hazard Risk Hazard Risk Hazard Risk

• Dielectric shoes (optional)
Category 0 Category 1/2 Category 3 Category 4

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PROBLEM
WITH TABLES:
Example: Example:
208 Volt Panel 480 Volt Motor Control Center
4,200 Amps Arcing Fault 16,000 Amps Arcing Fault
Clearing Time Over 2 Seconds Clearing Time .01 Seconds
Table Category: 1 Table Category: 2 w/ Double Layer Hood
Calculated: Category 4 Calculated: Category 0

Both examples, when removing bolted covers.

LBNL Uses a Hybrid System

REMEMBER!
• Calculations are
performed to PPE is your last resort!
determine incident
energy
• Hazard / Risk category Deenergized work is your priority!
is matched to incident
energy
• Table 130.7(C)(10) is Ask yourself…
used to determine PPE Have I analyzed this hazard?

Tools
Meters must be rated for the
voltage and location

• Must be appropriately rated for

voltage and energy levels.
• Undamaged.

Marking on rated
insulated tool per ASTM 1505

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Electrical Hazards - Summary Energized Electrical Work - Summary

What single work practice will MOST protect you and When an electrically safe work condition cannot be
other employees from electrical shock and arc- established, you must:
flash/blast hazards? • Have an approved energized work permit, which includes a
Job Briefing.
•Exceptions: Diagnostics/Troubleshooting, Voltage
measurements, current measurements, similar tasks,
which require an AHD.
• Establishing an electrically safe work condition.
• Establish a work zone.
• Wear both shock and flash protection PPE.
• Use insulated tools.

Any questions?
Arc Protection - Exercise
THANK YOU!

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