nfpa 70e - ion/apex electric · nfpa-70e nfpa stands for the national fire protection association....

NFPA

70E Electrical Shock

and Arc Flash

Awareness

Training

Course Objectives To provide an awareness of the hazards associated with

electrical work, provide and understanding of the energized

electrical work permit, and to train workers how to select the

appropriate personal protective equipment needed to perform

work safely.

Electrician's Safety References

National Electrical Code

(NFPA 70)

NFPA-70E OSHA

Sets the foundation for

electrical safety in

residential, commercial,

industrial occupancies.

Contains comprehensive

regulations for electrical

wiring, overcurrent

protection, grounding, and

installation of equipment

Created by Congress to

assure safe and

healthful working

conditions for working

men and women by

setting and enforcing

standards and by

providing outreach,

education and

assistance.

Addresses employee

workplace electrical

safety requirements.

Focuses on practical

safeguards that also

allow workers to be

productive within their

job functions.

A FEW FACTS

There are several other

NFPA standards.

There are several other

NFPA-70 standards

The E in the standard is

simply a sub-code

designation. It does not

stand for electrical.

NFPA-70E

NFPA-70E

NFPA stands for the National Fire Protection Association.

Its history dates back to 1911 as a sponsor to the National Electrical Code.

In 1976, the NFPA formed a new electrical standards development committee at the request of OSHA to develop an electrical safety standard. The purpose of this consensus standard is to provide a practical safe working area for employees relative to the hazards arising from the use of electricity.

OSHA has not adopted NFPA 70E due to a lengthy and expensive process, however, OSHA uses NFPA 70E in enforcement actions to serve as evidence of whether an employer acted reasonably. Employers and employees are expected to comply with it’s standards.

A FEW MORE FACTS…

NFPA-70E

This standard is comprised of 3

chapters.

Chapter 1 Safety-Related Work Practices

Chapter 2 Safety-Related Maintenance

Requirements

Chapter 3 Safety Requirements for

Special Equipment

This standard also contains 16 annexes

(A-P)

BRIEF SUMMARY OF THE LAYOUT…

NFPA-70E Chapter 1 Safety-Related Work Practices

Chapter 2 Safety-Related Maintenance Requirements

Chapter 3 Safety Requirements for Special Equipment

Annexes A-P

Terms and Definitions NFPA

National Fire Protection Association

NEC

National Electrical Code

OSHA

Occupational Safety and Health Administration

Electrically Safe Working Condition

A state in which an electrical conductor or circuit part 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.

Arc Flash

A dangerous condition associated with the possible release of

energy cause by an electric arc.

Shock Hazard

A dangerous condition associated with the possible release of

energy caused by contact or approach to energized electrical

conductors or circuit parts.

Terms and Definitions

Stay focused Arc Incident

What lead to the incident?

How could it have been avoided?

https://www.youtube.com/watch?v=hfnEuRA7-vo&feature=youtu.be

A state in which an electrical conductor or circuit part 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.



130.2. Energized electrical conductors and circuit parts shall

be put into an electrically safe work condition before an

employee performs work if any of the following conditions

exist:

The employee is within the limited approach boundary

The employee interacts with equipment where conductors or

circuit parts are not exposed but an increased likelihood of injury

from an exposure to an arc flash hazard exists.

(1)

If your work takes you

beyond this boundary, or…

(2)

If there is a chance by

interacting with the

equipment you could

cause an arc.

De-energize, lock it out and verify it is off.

The boundaries shown

here are greatly

exaggerated, we will

discuss these

boundaries in more

detail later in this

training.

Electrically

Safe Working

Condition

The safest way to

approach energized work

is to turn it off, lock it out

and verify it is off. This may

take more planning and

discipline, but eliminating

the risk is the safest

approach.

Electrically

Safe Working

Condition

In most cases substituting

electrical equipment and/or

engineering around the

hazard is not an option for

us. We can use

elimination, administrative

controls, and Personal

Protective Equipment.

De-energized

Free from any electrical connection to a source of potential difference and from electrical charge; not having a potential different from that of the earth.

Energized

Electrically connected to, or is, a source of voltage.

Exposed (as applied to energized electrical conductors or circuit parts).

Capable of being inadvertently touched or approached nearer than a safe distance by a person. Its is applied to electrical conductors or circuit parts that are not suitably guarded, isolated, or insulated.


Energized Work 130.2(A)(1),(2),(3) Lists 3 circumstances that permit work be

performed without placing equipment into an electrically safe

working condition.

Additional Hazards or Increased Risk

Infeasibility

Less than 50 Volts

Energized Work

Additional Hazards or Increased

Risk.

Energized work shall be permitted

where the employer can

demonstrate that de-energizing

introduces additional hazards or

increased risk.

Informational Note: Examples of additional hazards or increased risk include, but

are not limited to, interruption of life –support equipment, deactivation of

emergency alarm systems, and shutdown of hazardous location ventilation

equipment.

Energized Work Infeasibility

Energized work shall be

permitted where the employer

can demonstrate that the task

to be performed is infeasible in

a de-energized state due to

equipment design or

operational limitations.

Examples of work that might be performed within the limited approach boundary

of exposed energized electrical conductors or circuit parts because of infeasibility

due to equipment design or operational limitations include performing diagnostics

and testing (for example, start up or troubleshooting) of electric circuits that can

only be performed with the circuit energized and work on circuits that form an

integral part of a continuous process that would otherwise need to be completely

shut down in order to permit work on one circuit or piece of equipment.

Less than 50

volts

Energized

Work

EEWP

Energized Electrical Work Permit

PPE (Personal Protective Equipment)

Protective clothing or equipment designed to protect the wearer’s body from injury or infection.

Incident Energy

The amount of thermal energy impressed on a surface, a certain distance from the source, generated during an electrical arc event. Incident energy is typically expressed in calories per square centimeter. (cal/cm2)

JHA (Job Hazard Analysis)

A technique that focuses on job tasks as a way to identify hazards before they occur and take steps to eliminate or reduce them to an acceptable risk (This term refers to a process. However, many times the term is use to refer to a form that is used to carry out this process).


Risk assessment

An overall process that identifies hazards, estimates the potential

severity of injury or damage to health, estimates the likelihood of

occurrence of injury of damage to health, and determines if

protective measures are required.

Fault Current

Also known as a short-circuit current, a fault current is a term

used to describe a situation in which the flow of current that is

traveling through an electric circuit is not within a normal range.

Boundary

When an arc flash hazard exists, an approach limit at a distance

from a prospective arc source within which a person could

receive a second degree burn if an electrical arc flash were to

occur (Additionally boundaries also exist to protect from shock

hazards).


(EEWP) Energized Electrical Work Permit 130.2(B)(1) When Required. When energized work is

permitted, an energized electrical work permit shall be

required under the following conditions:

When work is performed within the restricted approach boundary

When the employee interacts with the equipment when

conductors or circuit parts are not exposed but an increased

likelihood of injury from an exposure to an arc flash hazard exists

(1)

If your work takes you

beyond this boundary, or…

(2)

If energized parts are not

exposed, but what you are

doing could result in an

arc flash (i.e. drilling, or

pushing a fish tape into a

panel, cabinet or gear).

If you cannot turn it off, and either of these 2

reasons apply, then you need an Energized

Electrical Work Permit.


here are greatly


discuss these

boundaries in more


training.

130.(3) Exemptions to Work Permit. An energized electrical

work permit shall not be required if a qualified person is

provided with and uses appropriate safe work practices and

PPE in accordance with Chapter 1 under any of the following

conditions:

Testing, troubleshooting , and voltage measuring

Thermography and visual inspections if the restricted approach

boundary is not crossed

Access to a and egress from an area with energized electrical

equipment if no electrical work is performed and the restricted

approach boundary is not crossed

General housekeeping and miscellaneous non-electrical tasks if

the restricted approach boundary is not crossed

(EEWP) Energized Electrical Work Permit

Overview of Form

Table 130.4(D)(a) for shock risk assessment (3’6” & 1’)

130.(C)(7)(a) Lists rubber gloves with leather protectors as

shock protection that shall be worn to protect from electric

shock. Gloves must be rated for the voltage for which the

gloves will be exposed.

Wilson’s Calculator for arc flash risk assessment

Calculator to determine incident energy and arc boundaries

Necessary protective equipment (see next slide)

Barricading beyond the arc boundary has advantages.

Tool and equipment storage, freedom to move about, etc.…

Job Hazard Analysis

Not too much, not too little.


IEA Spreadsheet REV 6.xlsx

Examples of protective

equipment

Arc Flash Risk Assessment

Incident Energy

The amount of thermal energy impressed on a surface, a

certain distance from the source, generated during an electrical

arc event. Incident energy is typically expressed in calories per

square centimeter. (cal/cm2)


Think of the amount of heat each group of candles (each calorie amount)

would generate on a single point (1 square centimeter) on your finger tip for

one second. Incident Energy is measured based on a similar principle.

1 cal/cm2

3 cal/cm2

7 cal/cm2

Ouch!!! cal/cm2

Incident energy during an arc event is affected by:

Available fault current

Clearing time of upstream overcurrent protective device. (how

much time the arc has to come thru; the quicker the trip time, the

better)

Wire size (smaller wire, more resistance decreases the energy)

Wire distance (distance provides resistance)

Whether a transformer involved in the system. (Generally, voltage

is induced in transformers. As a result there is no physical link to

carry potential energy from the primary system thru the

transformer).


Incident energy can be calculated using the Wilson’s

Calculator which is based on 2 formulas in the NFPA 70E

annex D.

We need to know incident energy levels to protect

ourselves from the dangers of an arc event.

Superior Glove Incident Energy video

What is Arc Flash


https://www.youtube.com/watch?v=K6iJN6kN-Is

Arc Flash boundaries

Also can be calculated using Wilsons Calculator

Can also be determined by using the Tables 130.7©(15)(A)(b)

and 130.7©(15)(B) according to equipment and electrical system.

(ac or dc).

Anyone inside the arc flash boundary must have on the

appropriate Personal Protective Equipment.


Examples of protective

equipment

If your work exposes you

to exposed energized

parts inside this boundary

you need arc rated

protective clothing and

equipment.

This is not a place for the customer or general

contractor. Don’t take chances.


here are greatly


discuss these

boundaries in more


training.

Arc Flash boundaries

Arc Flash Safety Boundaries video


https://www.youtube.com/watch?v=JIO-_VA1or4



Arc Flash Boundary.

Everyone inside this

boundary needs arc

rated PPE and

equipment

When dealing with exposed energized parts or

verifying equipment is de-energized

Limited Approach

Boundary. Primarily a

shock boundary but

could place you inside

the arc boundary as well.

Therefore, everyone

inside this boundary

needs arc rated PPE and

also protection against

shock. This worker

needs to be qualified to

work around energized

equipment or

accompanied by a

qualified worker.

When you cannot establish an electrically safe

working condition and are dealing with exposed

energized parts or verifying equipment is de-

energized.

Restricted Approach

Boundary. Primarily a

shock boundary but will

place you inside the arc

boundary as well.

Therefore, everyone

inside this boundary

needs arc rated PPE and

also protection against

shock. This worker

needs to be qualified to

work around energized

equipment. An EEWP

and JHA needs to be

completed.

When you cannot establish an electrically safe

working condition and are dealing with exposed

energized parts or verifying equipment is de-

energized.

(EEWP) Energized Electrical Work Permit Blank forms will be inside

the black boxes on site.

A sample form will be provided for Senior Foremen, Project Managers, Safety Supervisors to use as a guide.

Completed forms should be filed in the black box.

Calculations and new forms will be provided as needed.

Equipment Labeling

DuraLabel Label video (what is Arc Flash?)

130.5(D) Electrical equipment such as switchboards,

panelboards, industrial control panels, meter socket

enclosures, and motor control centers that are in other than

dwelling units and that are likely to require examination,

adjustment, services, or maintenance while energized shall

be field-marked with a label containing all the following

information:

Nominal system voltage

Arc Flash boundary

At least one of the following:

Available incident energy and corresponding working distance, or the

arc flash PPE category for the equipment

Minimum arc rating of clothing

Site-specific level of PPE

https://www.youtube.com/watch?v=Q-pmdl9jTzs

Exception. Labels applied prior to September 30, 2011 are

acceptable if they contain the available incident energy or

required level of PPE.

Equipment Labeling

If a label such as this is available, we can use it as a guide in selecting

the correct Personal Protective clothing and arc rated equipment.

Labels and Insulated tools

https://www.youtube.com/watch?v=GlTKyNxc98M

AIC Amperage Interrupting Capacity

Current Rating


Amperage Interrupting Capacity (AIC) The amperage interrupting capacity (AIC) of a circuit breaker

is the maximum short circuit current at which the breaker will

safely interrupt the circuit. The AIC is at the related voltage

and frequency.

In other words above this amperage, the breaker will either blow

apart or weld shut.

The amperage interrupting capacity (AIC) and the current

rating of a device differ in that:

The current rating Is based on the maximum current the device

will carry continuously without exceeding the specified limits of

observable temperature rise.

AIC rating

This device will either blow apart or weld shut during a fault in

which the incident energy reaches above 10,000 amperes.

Current rating

It is always good practice to check surrounding equipment to verify the

equipment you are working on has a trustworthy AIC rating.

Again what affects incident energy?

Incident energy during an arc event is affected by:

(1) Available fault current

(2) Clearing time of upstream overcurrent protective

device. (how much time the arc has to come thru; the

quicker the trip time, the better)

(3) Wire size (smaller wire, more resistance decreases

the energy)

(4) Wire distance (distance provides resistance)

(5) Whether a transformer involved in the system.

(Generally, voltage is induced in transformers. As a

result there is no physical link to carry potential energy

from the primary system thru the transformer).

MDP

65 KA 65 XFMR

22

22

10

75 ft.

125 ft.

15 ft. 10

ft.

Each breaker in MDP rated for 65 KA. 10 ft. and 15 ft. of

distance to panels in same electrical room. One has a

transformer in between. 75 ft. and 125 ft. of distance to

panels in field.

These rating appear trustworthy as the transformer and

distance cut down on available fault current.

MDP

65 KA 22

22

Transformer

22

10

75 ft.

125 ft.

15 ft. 10

ft.

XFMR

Suspicious?

Each breaker in MDP rated for 65 KA. 10 ft. of distance to panels

in same electrical room. One has a transformer in between. 75 ft.

and 125 ft. of distance to panel in field.

Not much distance between the 65 KA rated breaker in the MDP

and the 22 KA rated panel. Is it realistic to assume the AIC should

be calculated at only 22ka? What has impeded the incident

energy? Overcurrent protective device?

Amperage Interrupting Capacity (AIC)

Using standard AIC ratings

and Wilsons calculator, we

can quickly determine

incident energy levels in the

field.

Table H.3(b) requires that

protective clothing and

equipment should be worn at

and above 1.2 cal/cm2.

Above this amount of

energy a worker will

experience 2nd degree

burns.


10ka at 208v=0.67cal/cm2

14ka at 208v=0.87

18ka at 208v=1.05

22ka at 208v=1.23

25ka at 208v=1.35

42ka at 208v=2.01

45ka at 208v=2.11

65ka at 208v=2.79


10ka at 240v=0.71 cal/cm2

14ka at 240v=0.92

18ka at 240v=1.12

22ka at 240v=1.31

25ka at 240v=1.45

42ka at 240v=2.17

45ka at 240v=2.29

65ka at 240v=3.05


10ka at 480v=1.05 cal/cm2

14ka at 480v=1.44

18ka at 480v=1.81

22ka at 480v=2.18

25ka at 480v=2.45

42ka at 480v=3.96

45ka at 480v=4.22

65ka at 480v=5.92


Breakdown for AIC to EEWP & PPE quick glance

<10ka

Need EEWP & JHA

Usually below 1.2 cal/cm2

Shock is the greater of the two hazards

22ka> at 208 volt; 14ka at 480 volt>

Usually above 1.2 cal/cm2

Need EEWP & JHA

Need shock and arc protection

Usually need HRC 2 equivalent clothing


42ka> Need EEWP & JHA

Usually above 1.2 cal/cm2

Need shock and arc protection

Usually need HRC 4 equivalent clothing

Need involvement of the Safety Director

PPE possibly reduced depending on extensive research of

system.


Arc Rating

The value attributed to materials that describes their performance

to exposure to an electrical arc discharge. The arc rating is

expressed in cal/cm2 and is derived from the determined value of

the arc thermal performance value (ATPV) or energy of break

open threshold (EBT) (should a material system exhibit a break

open response below the ATPV value). Arc rating is reported as

either ATPV or (EBT) whichever is the lower value.

ATPV

Arc Thermal Performance Value


Incident Energy Analysis Method

Arc rated clothing and other PPE shall be selected and used by the employee based on the incident energy exposure associated with the specific task.

Categories Method

The use of Tables 130.7©(15) and 130.7©(16) for the selection of arc flash PPE

Hierarchy

A system or organization in which people or groups are ranked one above the other according to status or authority.

EEWP

Energized Electrical Work Permit


Arc Rated Personal Protective Equipment

Arc Rating video

When selecting clothing look for the (ATPV) Arc Thermal

Performance value, not just Fire Resistant.

Informational Notes:

ATPV is defined as the incident energy on a material or multilayer

system of materials that results in a 50% probability that sufficient

heat transfer through the tested specimen is predicted to cause

the onset of a second degree burn injury.

Ebt is defined as the incident energy on a material or material

system that results in a 50% probability of break open. (causing

a hole or opening).

https://www.youtube.com/watch?v=Ar4UAb3Uwh8

https://www.youtube.com/watch?v=Ar4UAb3Uwh8

Arc Rated

Personal

Protective

Equipment This means if you have

clothing that exactly

matches your incident

energy level, you have a

50% probability of

sustaining 2nd degree

burns.

Arc Rated

Personal

Protective

Equipment This is why according to

the hierarchy of risk

control, Personal

Protective Equipment is

considered the least

effective means to control

hazardous energy.

Turn it off

130.5(C)(1),(2)

When energized work must be performed, one of the

following methods shall be used for the selection of PPE.

Incident Energy Analysis Method

Arc Flash PPE Categories Method


The primary method used by Ion Apex employees will be the

incident energy analysis method.

This can be accomplished by using Wilson’s Calculator, or by

using the AIC ratings on the overcurrent protective device.

By means of this method, we can determine:

(1) the right protective equipment to use,

(2) know the available incident energy for the EEWP,

(3) know the arc boundary for the EEWP



These next slides will demonstrate the proper way to don the

arc rated equipment at each level using the incident energy

analysis method along with the Table H.3(b).


Long sleeve cotton shirt

Rubber gloves with leather protectors

Hearing protection

Safety glasses

Face shield (as needed)

Hard hat

cotton jeans

Below 1.2, and

generally at <10KA

Arc rated long sleeve shirt

Hearing protection

Face shield (as needed)

Safety glasses

Hard hat


cotton jeans

Cotton t-shirt

Variation of first picture.

Below 1.2, and generally

at 10ka depending on

clearing times.

Hard hat, arc-rated face

shield, arc rated balaclava,

safety glasses, hearing

protection


Equal to or

greater than arc-

rated coverall

Leather footwear

In our case with our

coveralls, 1.2 cal/cm2>

&<10 cal/cm2 or at 22KA

@ 240v or 14KA @ 480v


Leather footwear

Hard hat, arc-rated face

shield, arc rated balaclava,

safety glasses, hearing

protection

Equal to or greater

than arc-rated pants

Equal to or greater

than arc-rated long

sleeve shirt

Cotton t-shirt

Variation to previous

picture. In our case with

our coveralls, 1.2

cal/cm2> &<10 cal/cm2 or

at 22KA @ 240v or 14KA

@ 480v


Equal to or greater

than arc-rated flash

suit hood, hard hat,

safety glasses

Equal to or greater

than arc-rated flash

suit

Leather footwear

Hearing protection

According to 70E this is

the PPE for above>12

cal/cm2

With our coveralls it

would be above 10 cal.

Or 42KA>. Contact the

Safety Supervisor.

Other Precautions 130.6(A)(2) When impaired. Employees shall not be

permitted to work within the limited approach boundary of

energized electrical conductors or circuit parts operating at

50 volts or more, or where other electrical hazards exist,

while their alertness is recognizably impaired due to illness,

fatigue, or other reasons.

Other Precautions 130.6(B) Blind Reaching. Employees shall be instructed not to

reach blindly into areas that might contain exposed energized

electrical conductors or circuit parts where an electrical hazard

exists.

130.6(D) Conductive Articles Being Worn. Conductive articles of

jewelry and clothing (such as watchbands, bracelets, rings, key

chains, necklaces, metalized aprons, clothes with conductive

thread, metal headgear, or metal frame glasses) shall not be worn

within the restricted approach boundary or where they present an

electrical contact hazard with exposed energized electrical

conductors or circuit parts.

130.6(L) Routine Opening and Closing of Circuits. Load rated

switches, circuit breakers, or other devices specifically designed as

disconnecting means shall be used for the opening, reversing, or

closing of circuits under load conditions. Cable connectors not of the

load-break type, fuses, terminal lugs, and cable splice connections

shall not be permitted to be used for such purposes, except in an

emergency.

Other Precautions

130.6(M) Reclosing Circuits After Protective Device Operation. After

a circuit is de-energized by the automatic operation of a circuit

protective device, the circuit shall not be manually reenergized until

it has been determined that the equipment and circuit can be safely

energized. The repetitive manual reclosing of circuit breakers or

reenergizing circuits through replaced fuses shall be prohibited.

When it is determined from the design of the circuit and the

overcurrent devices involved that the automatic operation of a

device was caused by an overload rather than a fault condition,

examination of the circuit or connected equipment shall not be

required before the circuit is reenergized.

Other Precautions

Conclusion The moral of the story is BE SAFE and NEVER take

chances. One mistake could change you or your family’s life

forever.

Concluding Video

OEL Arc Flash Wear

Test

Practice donning the PPE

https://www.youtube.com/watch?v=Acch6mNJ-6o

nfpa 70e - ion/apex electric · nfpa-70e nfpa stands for the national fire protection association....

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