ARC FLASH SAFETY

1

By: John Alvarez

johnsafetyfirst10@yahoo.com

ELECTRICAL ARC FLASH

• There are about 2,000 or more serious burn injuries

and dozens of deaths related to arc flashes per

year

• Even if you don’t work directly with electricity you

should know the dangers of an arc flash

• Safety guidelines could help so that you don’t get

hurt or your Co workers

• Never do any electrical work unless you are

completely authorized and consider qualified by

the facility owner.

2

WHAT IS AN ELECTRICAL ARC FLASH?

An electrical explosion due to a high-current short

circuit which presents a hazard to

qualified/authorized electrical workers.

3

ARC FLASH EXPLOSION

• Arc flashes can cause:

• Third – degree burns

• Blindness

• Cardiac arrest

• Broken Bones Hearing loss

• Punctures and lacerations

4

CAUSES OF ARC FLASH

• Testing the voltage with inappropriate tools

• Dropped tools

• Improper work procedures

• Not insulated properly

• Working on energized equipment

• Dust and corrosion

• Lack of training

WHAT IS NFPA 70E?

• NFPA stands for National Fire Protection

Association.

• NFPA 70E “Standard for Electrical Safety in

the Workplace” has created heightened

awareness of electrical arc flash hazards.

Applicable to systems 50 volts and above.

• Affects: Training, Labeling, Personal

Protective Equipment (PPE), Tools, Work

Practices.

6

WHO ENFORCES ELECTRICAL ARC FLASH SAFETY?

• Electrical panels and designs are required to

provide labeling per NEC 110.16 requirements.

OSHA 1901.132 and 1910.335 require that

employers perform a hazard assessment to

determine proper PPE and that employees be

provided with and are required to use

appropriate PPE properly.

7

WHAT ARE WE PROTECTING AGAINST?

• Shock Hazard with PPE, Distance, or Safety design.

Assuming 480v and less.

• Default Qualified Boundary is 1 foot

• Default Unqualified Boundary is 42 inches

• Arc Flash Hazard with PPE, Distance or Safety

design.

• Default boundary is 4 feet without PPE.

8

PPE SELECTION

• NFPA 70E-28 Article 130.7 Personal and Other Protective Equipment.

• When a employee is working within the “Flash Protection Boundary” (4 feet of exposed live parts) he/she shall wear protective clothing and other PPE in accordance with 130.3

• Protective equipment, sufficient for protection against the potential electrical flash, is required for every part of the body. The selection of the required thermal rated PPE depends on the incident energy level at the point of work.

• Employees must wear and be trained in the use of appropriate protective equipment for the possible electrical hazards with which they may face..

9

CLOTHING

• Category – 0 Untreated natural fiber that doesn’t

melt like cotton or wool

• Category – 1 wear clothing that is flame resistant or

FR

• Category – 2 Wear cotton under garments and FR

clothing

• Category - 3 Wear cotton undergarments, FR

CLOTHING AND FR COVER ALL

• Category -4 Cotton undergarments, FR clothing

and a double layer coat and pants

10

PPE

• Some jobs may require

specific PPE:

• Such as; arc rater face shield, safety glasses, voltage

rated hard hat, insulated gloves and insulated shoes or

boots and hearing protection. Or a full arc flash suit.

• PPE need to be rated for the amount of incident energy

that can withstand this is called:

• Arc Thermal Performance Value or ATPV

• Manufactures provide the ATPV Ratings in the clothing if

a piece of clothing doesn’t have an ATPV Is not an

acceptable protection against arc flash dangers.

11

4- FLASH PROHIBITED APPROACH

• 1. The Prohibited approach.

• 2. Restricted approach.

• 3. Limited Approach Boundary

• 4. Flash Protection Boundary

• For high voltage protection it could be as far as 20

feet and for low voltage it could be up to a few

inches.

12

13

4- FLASH PROHIBITED APPROACH

• For someone to cross the flash protection boundary

and any of the shock boundaries he must be

authorized by the owner of the equipment and

wear the proper PPE FOR THE JOB THEY ARE DOING.

• All hazards, equipment that has been installed or

modify after 2002 must have warning signs or labels

that tell the hazards that are present.

14

DE –ENERGIZED

• Best way when working with electricity is to apply LOTO procedures.

Dozens of workers kill every year for not following the lock out tag out procedures

• Employees need to know the lockout Tag out procedures

• Required PPE

• Work permit procedures

• Emergency Procedures in the event of an

arc flash or electric shock.

• Always pay attention to all signs and labels

15

CAN DOUBLE INSULATED AND VOLTAGE RATED TOOL HELP?

• YES! Non-insulated tools introduce an arc flash risk that is minimized with properly rated insulated tools. Note that the tools must be marked with the following voltage rated symbol by the manufacturer.

16

ARC FLASH

• Arc flashes are extremely dangerous and could

injure or kill workers. You don’t have to come into

direct contact with electricity to get seriously injured

with an arc flash that is the way is so important to

know all of the dangers associated with.

• Always pay attention to all the labels and always

put on the CORRECT PPE.

• Following safe work practices will reduce the

chances that you or your coworkers get hurt by one

17