Arc Flash Regulations & Requirements

Updated 12/07

Welcome

OR

How to work “live” without making an ash of yourself *

Regulations & Requirements

Arc Flash

* Credit to Regional OSHA Training Coordinator

Arc flash is a short circuit through air that flashes over from one exposed live conductor to another conductor or to ground.

Lightning is an example of a naturally occurring arc flash.

What is Arc Flash?What Is Arc Flash?

TYPICALLY LASTS LESS THAN A SECOND

EXTREMELY HIGH RADIANT ENERGY

EXPLOSIVE IN NATURE

CAN IGNITE AND/OR MELT CONVENTIONAL WORK CLOTHING

Electric Arc Facts

50 cal/cm22000 psf

< 740 mph

1000 °C

Visible

UV

IR

165 db15000 °C

Slide Courtesy of Oberon

From Arc Flash: Severe burns from heat and molten metal

Damage to eyesight

From Arc Blast: Loss of brain function due to concussion

Hearing loss from ruptured eardrums

Shrapnel wounds from flying metal parts

Other injuries from force of explosion

ARC FLASHArc Flash Injuries

Most hospital admissions due to electrical accidents are from arc flash burns, not from electrical shocks!

Of the 350 workers killed by electricity in 2005, 50% were related to arc flash

5 to 10 arc flash incidents occur in the USA each day, resulting in an average estimated 1 death every other day

ARC FLASHHow Common Is It?

DEATH …

Or years of medical treatment, with costs from $1-5 million for

severe burns

Victim may never return to work or enjoy same quality of life!

OSHA fines, civil lawsuits

Equipment damage, production loss

ARC FLASHWhat Are The Costs?

Bottom Line DON’T! De-energize and Lockout/Tagout instead. 80% of the electrical fatalities in this country occur

where the power could have been off. Reasons Given For Working Live:

Not wanting to pay overtimeSlows production downTakes too long - inconvenient

“Safety has priority over service continuity, equipment damage or economics”… Institute of Electrical and Electronic Engineers ‘Buff Book’

The First Rule About Working “Live”

“Live parts to which an employee may be exposed shall be de-energized before the employee works on or near them, unless the employer can demonstrate that de-energizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations.”

OSHA 1910.333(a)(1) De-energized Parts

Accidental contact or even just positioning a conductive object too close to high-amp current

Sparks (dropping tools, racking breakers, etc.)

Equipment or circuit breaker failure

Breaks or gaps in insulation

Dust, corrosion, other impurities

Fumes or chemical vapors

ARC FLASHWhat Can Cause Arc Flash?

Installing conduits & bus duct switches

Working on control circuits

Cleaning starter buckets in a MCC

Applying safety grounds

Operating disconnect switches and breakers

Taking a voltage reading

Removing, installing circuit breakers or fuses

Anytime you’re inside the Flash Protection Boundary

ARC FLASHWhen Are You Exposed?

OSHA 29 CFR Subpart S, 1910.331 – 335 “Electrical Safety Related Work Practices”

NFPA 70E-2004 “Standard For Electrical Safety In The Workplace” To order call 800-344-3555 or go to www.nfpacatalog.org

IEEE 1584 “Guide For Performing Arc Flash Hazard Calculations” To order call 800-701-4333 or go to http://standards.ieee.org

ANSI / NFPA 70-2005 National Electric Code

ARC FLASHArc Flash Regulations

OSHA IS THE SHALL &NFPA 70E IS THE HOW

Industry consensus standards, notably NFPA 70E, can be used by employers as guides to making the assessments and equipment selections required by the standard. Similarly, in OSHA enforcement actions, they can be used as evidence of whether the employer acted reasonably.

NFPA 70E

Objective of arc flash regulations is to limit injury to curable 2nd degree burns.

Adhering to min. requirements does NOT:

Eliminate risk of burn injury completely

Protect workers from effects of arc blast

Regulatory ObjectivesRegulatory Objectives

Incident energy determined by:

Magnitude of fault current

Duration of arc fault

Distance from flash source

Research shows that incident energy of approx. 1.2 cal/cm² will cause a 2nd degree burn.

ARC FLASHIncident Energy

Flash protection boundary should be set at point where incident energy equals 1.2 cal/cm²

When work on live exposed parts is in progress:

Unprotected workers must remain outside flash protection boundary.

Workers inside boundary must wear proper flash protection clothing.

ARC FLASHFlash Boundary

NFPA 70E defines five levels of arc flash hazards:

Category 0 (low risk) through Category 4 (high risk)

Protective apparel requirements shown in table 130.7(C)(10) of NFPA70E-2004

Cat. Arc Rating Clothing Description

0 NANon-melting, flammable materials (ie., untreated cotton, wool, rayon, or silk,or blends of these materials) with a fabric weight at least 4.5 oz / yd² [1 layer]

1 4 cal / cm² FR shirt and FR pants or FR coverall [1 layer]

2 8 cal / cm²Cotton underwear (conventional short sleeve and brief/shorts), plus FR shirt and FR pants [2 layers]

3 25 cal / cm²Cotton underwear plus FR shirt and FR pants plus FR coverall, or cotton underwear plus two FR coveralls. [3 layers]

4 40 cal / cm²Cotton underwear plus FR shirt and FR pants plus multilayer flash suit [3 or more layers]

ARC FLASHProtective Clothing

Protective equipment requirements are covered in Table 130.7(C)(10) of NFPA70-2004

Category 0 Category 2 Category 4

Hard hat X X

FR hard hat liner X

Safety glasses or goggles X X X

Arc-rated face shield X

Flash suit hood X

Hearing protection X X

Leather gloves X X

Leather shoes X X

ARC FLASHPersonal Protective Equipment Requirements

Before arc flash After arc flashDuring arc flash

Untreated cotton shirt (5.7 oz/yard²)

ARC FLASHFlammable Clothing

Before arc flash After arc flashDuring arc flashDuPont NOMEX® IIIA Shirt (4.5 oz/yd²)

ARC FLASHFlame Resistant Clothing

The flash hazard category can be determined in either of two ways:

Use table 130.7(C)(9)(a) Hazard / Risk Category Classification in NFPA 70E-2004

Perform flash hazard analysis as described in 130.3 of NFPA 70E-2004

ARC FLASHDetermining The Flash Hazard Category

Article 110.16 of the ANSI / NFPA 70-2005 National Electric Code states:“Switchboards, panelboards, industrial control panels, meter socket enclosures, and motor control centers that are in other than dwelling occupancies and are likely to be subject to examination, adjustment, servicing or maintenance while energized must be field marked to warn qualified personnel of potential arc flash hazards. The marking shall be located so as to be clearly visible to qualified persons before examination, adjustment, servicing or maintenance of equipment.”

NEC2008 Adds: - Electrical equipment such as…… - Multiple occupancy dwellings not exempt

ARC FLASHLabeling Requirements

Labeling is responsibility of owners, not equipment manufacturers or suppliers.

Applies to all new installations and as well as any existing installations that are added, altered or modified in any way.

Many companies taking safe (and efficient) approach of labeling all existing installations.

ARC FLASHNew vs. Existing Installations

Current regulation says only that label must warn of arc flash hazards.

2” x 4”

3.5” x 5”

Bilingual (En/Sp) labels also available

ARC FLASHGeneric Labels

Many employers including additional info such as hazard category and required arc flash PPE

Others also providing shock hazard information

ARC FLASHWrite-On Labels

Labels with preprinted hazcat and PPE mean less writing, less chance of someone making a mistake

ARC FLASHPre-Printed Labels

Send data in spreadsheet and have Brady print for you Print using Brady industrial label printing systems

ARC FLASHCustom Printed Labels

MarkWare™ Software

+

GlobalMark® printer

or

MiniMark™ printer

ARC FLASHFacility ID Label Printers

Print arc flash labels to Brady industrial labeling printers direct from 3-party power management programs such as:

SKM

ETAP

ESA EasyPower

ARC FLASHPower Management Software

Required by NFPA 70E when working live

Allows relevant hazards and safe work practices to be specified on a job by job basis

Ensures proper mgmt control of high-risk work activities

ARC FLASHElectrical Work Permits

Promote awareness of the dangers associated with arc flash accidentsAnd make sure your employees know how to protect themselves!

ARC FLASHTraining Tools

Lockout before service and maintenance Follow approved safe work procedures Wear proper protective apparel and equipment Use insulated gloves, tools, blankets and barriers Keep equipment free of dirt and corrosion Operate equipment at the rated voltage Be careful to avoid generating sparks

ARC FLASHProtect Yourself!

Other areas where Brady can help:

Lockout / Tagout

Hazardous chemicals / Right-to-Know

Slips & Trips

Process & equipment identification

5S and Lean Manufacturing

Production tracking and product labeling

ARC FLASHStay Safe – Brady Can Help!