04/18/23

AFCI 9/01/07 Rev 5 1

Arc Fault Circuit Interrupters

For NEMA Field Reps

AFCI 9/01/07 Rev 5 2

1900 1930 1950 1970 1990 2000

2-Conductor BXReplacing Knob & Tube

Knob & TubePrimary Wiring

Aluminum BondingStrip Required On BX

Aluminum Armored BX Cable & NM-B Primary Wiring

Wir

ing

Residential FusesPrimary Protection Of Circuit

Innovative Circuit Breaker Products And Fuses Used For

Circuit Protection

Thermal Magnetic Circuit Breakers Protect Residential

Circuits

Standard Thermal Mag Arc Fault & Dual Function

Circuit Breakers Used For Circuit Protection

Cir

cuit

P

rote

ctio

n

Residential Homes Are Safer Because Of Codes and Standards

Ground Fault Protection Begins In the 70’s On Swimming Pools (Electrocutions ~ 1100/ year)

‘70s: Bathroom, Garage, And near pools ’80s: Whirlpools, Tubs, Kitchen Sinks‘90s: Basements, Crawl Spaces, Wet Bars, Kitchens’00s: Outside and Other Locations (Electrocutions ~ 400/year)

With Ground Only Required

In laundry room

ExpandedBasements,

Garages, Outdoors

ExpandedRest Of HomeNo Ground Required

Rec

epta

cles

&G

rou

nd

Fau

ltCircuit Protection Progress Continues

2020

AFCI 10/2014

• Each year, approximately 68,000 fires in the US are caused by problems in a residential electrical systems• These fires result in thousands of injuries and billions of dollars in overall economic impact

Electrical Arcing Can Happen Anywhere

AFCI 9/01/07 Rev 5 4

Typical Causes of Arc Faults

Example Conditions Where Arc Faults May Start Include:

• Damaged Wires.

• Worn Electrical Insulation.

• Wires Or Cords In Contact With Vibrating Metal.

• Overheated Or Stressed Electrical Cords And Wires.

• Misapplied Or Damaged Electrical Appliances.

AFCI 9/01/07 Rev 5 5

Examples of Arc Fault Causes

Furniture pushed against electrical cords

Extension or appliance cords that have worn/cracked

insulation

Cables that are improperly nailed or stapled too tightly

Wires punctured by a screw or drill bit

Nails driven into walls can break wire

insulation

AFCI 9/01/07 Rev 5 6

Research Helped Drive Industry Solutions

• 1992 The Consumer Products Safety Commission(CPSC) Initiated The “Home Electrical System Fires Project” To assess The Products And Technology That Could Potentially Decrease The Likelihood Of Residential Fires

• UL Summarized That Arc Fault Detection Is The Most Promising Technology In The Prevention Of Hazardous Arcing Faults

AFCI 9/01/07 Rev 5 7

What Are Arc Fault Circuit Interrupters (AFCI)

• AFCI Technology Provides Increased Protection Over A Conventional Circuit Breaker By Detecting A Condition Known As An “arc fault.”

• AFCIs Utilize Advanced Electronic Technology To “sense” Different Arcing Conditions.

• AFCIs Are Designed To Recognize When Arc Faults Occur And Automatically De-energize The Circuit In Order To Mitigate Fire Initiation.

AFCI 9/01/07 Rev 5 8

AFCI Types

Branch Feeder Type – Provides Protection Of The Branch Circuit Wiring, Feeder Wiring, or Both, Against Unwanted Effects of Arcing. This Device Also Provides Limited Protection To Branch Circuit Extension Wiring.

Combination Type – Protects Downstream Branch Circuit Wiring, Feeder Wiring, Cord Sets And Power-Supply Cords Against The Unwanted Effects Of Arcing.

Arcing – High Current Arcing – Low Current

Introduction Of Branch Feeder AFCI To The National Electrical Code. Protection Of Branch Circuits Supplying Bedroom Receptacle Outlets As Of January 1, 2002.

Listed Branch Feeder AFCI Protection Of Branch Circuits Supplying Bedroom Outlets.

• Branch Circuits Supplying Outlets Installed In Dwelling Unit Bedrooms Shall Be Protected By A Listed Arc-Fault Circuit Interrupter, Combination Type, Installed To Provide Protection Of The Branch Circuit.

• Branch Feeder AFCI’s Permitted To Be Used Until January 1, 2008.• Location Of The AFCI Is Permitted To Be Within 6’ Of The Origin Of The

Branch Circuit Via A Metal Raceway Or A Cable With A Metallic Sheath.

Combination-Type AFCI Required On Bedroom, Family Rooms, Living Rooms, Parlors, Libraries, Dens, Sun Rooms, Recreation Rooms, or Similar Rooms. It Shall Be Permitted To Install A Combination AFCI At The First Outlet. RMC, IMC or EMT or Steel Armored Cable, Type AC, Meeting The Requirements of 250.118, Using Metal Outlet or Junction Boxes Must Be Installed Between The Origin of the Branch Feeder and the First Outlet.

NEC AFCI GFCI requirements timeline

0

3

8

3

AFCI Req’d

Added requirement for arc fault protection in kitchens and laundries while specifying that both outlets and devices need to be protected. This presumably means refrigerators, microwaves, dishwashers and washing machines now require protection. Additionally the outlets in these locations require GFI protection. This opens the door for a dual breaker as a potentially economical solution.. Also provided additional ways to use Outlet branch circuit AFCI devices although currently there is no way to execute economically..

8 Same as 2008 with clarification on Fire alarm circuits and renovation work. .

14 (3 dual)

AFCI 9/01/07 Rev 5 10

2005 NEC Branch Feeder CoverageBedroom 1 Bedroom 2Bathroom

Living Room

Kitchen

Family Room

UnfinishedBasement Den

Hallway

• Green Highlighted Rooms Are Those Required To Be Protected By AFCI

• Red Highlighted Rooms Are Those Not Required To Be Protected By AFCI

• Outside Receptacles Also Do Not Require AFCI Protection

Kitchen/Laundry

AFCI 9/01/07 Rev 5 11

2008 NEC Combination AFCI CoverageBedroom 1 Bedroom 2Bathroom

Living Room

Kitchen

Family Room

UnfinishedBasement Den

Hallway

• Green Highlighted Rooms Are Those Required To Be Protected By AFCI

• Red Highlighted Rooms Are Those Not Required To Be Protected By AFCI

• Outside Receptacles Also Do Not Require AFCI Protection

Kitchen/Laundry

AFCI 9/01/07 Rev 5 12

“(A) Dwelling Units. All 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices installed in dwelling unit

kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sun rooms, recreation rooms, closets, hallways, laundry areas,

or similar rooms or areas shall be protected by any means described in 210.12(A) 1-6

2014 NEC – Article 210.12

AFCI 9/01/07 Rev 5 13

2014 NEC Combination AFCI CoverageBedroom 1 Bedroom 2Bathroom

Living Room

Kitchen/Laundry

Family Room

UnfinishedBasement Den

Hallway

• Green Highlighted Rooms Are Those Required To Be Protected By AFCI

• Red Highlighted Rooms Are Those Not Required To Be Protected By AFCI

• Outside Receptacles Also Do Not Require AFCI Protection