arcflashandnfpa70e_erwinbrandt

7/30/2019 ArcFlashandNFPA70E_ErwinBrandt

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Presented byEWB Engineering, LLC.


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To Understand What is An Arc Flash

Why OSHA Is Addressing This Issue

Requirements In NEC & NFPA 70E Impact to Industry

Benefits to com letin an Arc-Flash

Assessment


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Arc Flash Event

Every Day-

Electricians

Injured byan Arc Flash

Event


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An Arc Flash isa Sudden

Release of Heatand EnergyCaused By An

Arc ResistantSwitch ear

,Additional

Undergoing Test

For an Arcing Fault

Shock


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Arcing faults in power distribution can produceintense 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

n ur es rom arc as re er a most exc us ve y tothe effects of burns received


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Arc Blast- 6,000 lbs force won workers chest

from moderate fault at MCC

- Pressure can cause collapsed lungs,concussion, etc.

Molten copper Vaporized copper expands

, x upon vapor zat on Shrapnel Arc Blast can create projectiles


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Accidental Contact- Mis laced tools

- Voltage testers

Rodents

-(Maintenance)


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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

.

regarding hazards and PPE and to verify that the required

assessment was performed through a written certification

en yng e wor pace evauae .


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Final Rule 72:7135-7221 Revises CFR 1910 Sub art S based onNFPA 70 (NEC) 2002 . Includes revised Reference to NFPA 70E-

2000 (see also NFPA 70E-2004).

Effective August 13, 2007SUMMARY: The Occupational Safety and Health Administration (OSHA) is revising

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,

Protection Association's (NFPA) Electrical Safety Requirements for Employee

Workplaces (NFPA 70E), and the 2002 edition of the National Electrical Code (NEC),

are reasonabl necessar to rovide rotection from these hazards. This final rule

focuses on safety in the design and installation of electric equipment in theworkplace. 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 areference to OSHA's electrical installation standard.


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employers meet the content of OSHA 1910 subpart S

- , par ap er paragrap - . .

Requires an arc-flash hazard analysis to be performed to

determine the level of hazard and the appropriate PPE forthe given task

.

warn qualified persons of potential arc flash hazards.

- e o oogy o compe e e arc as cacua ons


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qualified persons of potential electrical arc

flash hazards.


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Rackin a breaker on an ener ized bus

Removing covers

Volta e checks or troubleshootin

Application of safety grounds after voltage test


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Flash Protection Boundary

Incident Arc Ener Hazard Level for PPE


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IEEE Method Preferred (Detailed CalculationsRe uired

NFPA 70E Tables

Can Be Used if Detailed Calculations NotAvailable

Limited Range of Fault Currents and Protective


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a ate nergy rom as

Radiated Energy Function of

Arc Power

Distance From Arc

AC Volts Time to Extinguish Arc

Arc Voltage & Arc Current

Arc Gap


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A distance from

parts withinwhich a erson

could receive asecond degreeburn.


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Situation: We have a Main SWBD that has five fused disconnect

Switches that is fed from a 2500KVA utility owned pad mounted

transformer 100 of 6ea 500 MCM cable per phase

We received the primary fuse information and the available fault

current from the utility

Need to determine working distance 36

IEEE 1584 equations determine arcing fault current is approximatel36KA. It will take the utility fuse 2.5 secs to clear.

- 2

AFPB of 10.


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Example of using the Table Method:

What is the required Arc-Flash PPE for operating a Fused

Disconnect Switch located on the Plants Mains SWBD operating

Table 130.7(C)(9) CB or Fused Switch operation with the covers

Note1: Maximum of 25KA short circuit current available:

Maximum of .03 sec fault clearing time.


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Since we dont meet the requirement of Table 130.7(C)(7)Wecannot use the Table Method for the Main SWBD.

This doesnt mean we cannot use the table at other locations.owever snce e au curren s arge an e au cearng

times are usually longer, the table is not valid here. We might

plant.


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Points to using the Table

1. You still have to understand your electrical

distribution system

2. Need to determine fault currents and

clearing times

3. Need to understand the task


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.

2. Working distance is important

.

4. Type of equipment is an important factor in

5. Identifies device deficiencies

.


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Category Cal /cm2 FR Clothing(Minimum Rating)

n rea e o on, ong eeve

Hearing Protection, Eye Protection

Coveralls, Face Shield, HearingProtection

2 8 FR Shirt & FR Pants or FRCoveralls, Face Shield, Hearing

Protection

3 25 FR System, FR Hood, HearingProtection

ame as a ove excep g errating


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An important point to remember .

Personal Protective Equipment is the last line of

defense makin smart sa et decisions toprevent an arc flash from occurring must be atop priority


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How do we prevent an arc-flash from happening?

There is no fool proof way, however we can minimize theopportunities and its effect.

- Training: NFPA 70E states that only qualified people

should operate and perform maintenance on electrical.

Qualified person must understand and be able to mitigate thehazards, know and understand the shock and arc-flash

,

- Equipment Maintenance: Protection devices must beproperly rated and must function as designed to clear an

arcing fault. PPM can be used to identify problems beforethey happen (ie. IR scans).


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-

compliance with the OSHA requirements.

e anayss prov es recommen a ons o e mnae or re uce e

arc-flash hazard.

The analysis provides recommendations to improve reliability thru

better coordination between protective devices.

The analysis provides recommendations to eliminate fire hazards

due to misapplication of protection devices


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The analysis identifies potential issues with inadequate protective

device ratings. This can lead to major equipment damage duringan electrical fault and ex ose ersons to increased risk of an

arc-flash.

design process for future changes or expansion saving money.

e anayss en es oppor un es o re uce e requre arc-flash PPE


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Anticipated Benefits:

Employee Safety Primarily improving employee and

,

includes:

Reducing the exposure from arc flash ac ng e requremens o e nee , us

reducing PPE cost

Establish a means to properly label and rate overcurrent

protection.


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Establish Legacy Process:

Establish baseline for overall system design, control

.

Improve change management capability, and

Provides critical information for design practices and

reviews


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1. Train your employees

2. Have a Documented Lock out Procedure

3. Electrical Workers must meet the OHSAs definition of qualified.

Skills and knowledge, safety training, the use of PPE

4. Conduct job briefings (toolbox meetings) JSA or JHA

5. Complete a Hazard Assessment, Document and Label


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OSHA & NFPA 70E Require An Arc FlashHazard Anal sis For Pro er PPE

Re uirement in NEC States That Arc FlashWarning Labels Be Placed on Electrical Panels

and Switchboards.

IEEE 1584 is Preferred Method for Determining

Boundaries. Fault Study

Coordination Study

Determine Incident Arc Energy and Boundary


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Do I rea y nee to t is? Is OSHA rea y going to

enforce this? OSHA does not sa s ecificall that ou must com lete an

Arc-Flash Analysis. OSHA does say that you must evaluatethe hazards that exist in your facility. This includes electricalhazards and have a policy that address the required PPEneeded when ex osed to the hazards. OSHA will refer to theNEC and NFPA as recognized industry standards to operateby. NFPA chapter 2 does say an Arc-Flash Analysis must becompleted when working on or near energized equipment.NEC 110.16 states the e ui ment must be marked to warn

qualified persons of potential electrical arc-flash.

In August of 2007 OSHA revised CFR 1910 Subpart S based.

NFPA70E 2000 and 2004


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We do not work on ener ized e ui ment.

Do you do voltage checks, rack breakers in orou on an energ ze us

Do you apply safety grounds or remove covers

for infarred thermo ra h ?

If the answer is yes then an arc-flash

ana ys s mus e comp e e e ore ese ascan be completed.


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W at are t e ene its o oing t is type oanalysis?

Provides the knowledge of best possible PPE

for electrical workers Potentia y owers insurance premiums Increases knowledge of their electrical

Enhances system reliability Enables eas chan es and u rades Drastically lessens their chances of having to

make a very unpleasant visit to survivors


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What kind of data is needed?

lengths, relay or breaker settings and sizes,

transformer nameplate info, and any large. .the facility has onsite generation, it will beevaluated if depending on the size and

percen age o eman


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think we are in compliance.

What level did you purchase? How do you

know it is ade uate for all volta e levels andtask? You cant know these withoutcompleting an analysis


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-

www.chickenswitch.com-

Light Heat Sensors ABB

o on e ec ors emems

Maintenance Relay Switches Major OEMs

one nter oc ng re ay ng a or s High Resistant Grounding

Arc-Resistant Switchgear Major OEMs

IR Viewing Windows

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