How to Determine when to Use Arc Fault Circuit Interrupters (Af Circuit Breakers)
Determine the structure type., Identify circuit destinations., Determine if an exemption applies., Choose a method of providing protection., Provide both AFCI and GFCI protection where required., Add AFCI protection voluntarily.
Step-by-Step Guide
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Step 1: Determine the structure type.
If circuits are installed in a space for use other than a dwelling unit, AFCI is not required (commercial and industrial spaces are not required to have AFCI protection).
AFCI protection is required only in dwelling units (apartments, homes, manufactured homes, RVs and mobile homes). -
Step 2: Identify circuit destinations.
All 120 volt / 15 or 20 amp branch circuits supplying outlets (includes both lighting outlets and receptacle outlets) in dwelling unit family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sun rooms, recreation rooms, closets, hallways, or similar rooms or areas shall be protected by a listed arc fault circuit interrupter.
This means that nearly every habitable space in new homes are required to have this protection. , Most fire and smoke alarm systems are prohibited from being connected to GFCI or AFCI circuits.
Absent from the list of spaces that require AFCI protection are outdoors, laundry rooms, unfinished basements, attics and garage spaces, to name a few.
Circuits that provide more than 20 amps or more than 120 volts (208 / 240 volts circuits) are also exempted from AFCI protection.
That means most electric ranges, water heaters, clothes dryers, permanently installed electric heaters (baseboard and blower types), artesian well pumps, etc. are exempt because they are supplied by double-pole circuit breakers which puts them on 240 volt circuits and / or rated at more than 20 amps. , AFCI protection is provided by either an AFCI circuit breaker installed at the electrical panel, or by a receptacle specifically identified as providing arc fault protection.
Both the circuit breaker and receptacle are installed similar to the GFCI circuit breakers and receptacles that are present in many homes already.
The circuit breaker method protects the entire circuit, while the receptacle protects only from the point of installation on the circuit, to the end of the circuit.
A caveat for the receptacle method is that it is only considered meeting the code requirements if the portion of the circuit between the electrical panel and the AFCI receptacle is installed in pipe or armored cable and all boxes in the circuit must be metal (the common practice of using plastic / fiber boxes or romex cables would prohibit this solution). , Any required GFCI protected receptacle(s) that are installed in a location that additionally requires AFCI protection (see list above), will have to be AFCI protected as well.
It is possible to install an AFCI receptacle on a circuit protected by GFCI circuit breaker to satisfy the requirement but only if at least the portion of the circuit between the panel and the AFCI receptacle is installed in pipe or armored cable and all boxes in the circuit must be metal (the common practice of using plastic / fiber boxes or romex cable would prohibit this solution).
In this case, install an AFCI circuit breaker and a GFCI receptacle.
The pipe, armored cable, metal box, etc. limitations on AFCI receptacles are not applicable to GFCI receptacles.
Some manufacturers offer circuit breakers that provide both AFCI and GFCI protection in a single package. , Existing installations are not required to upgrade to AFCI protection.
In homes without AFCI devices, the ultimate protection would be to provide AFCI protection throughout the dwelling (except for circuits that have problems with AFCI).
Replace all existing single pole 15 and 20 amp circuit breakers (and any double pole 15 and 20 amp circuit breakers that supply circuits with shared neutrals that provide two 120 volt circuits), or replace the first receptacle on a circuit to an AFCI type to add this protection.
Use AFCI circuit breakers to add arc fault protection to the entire length of existing circuits.
This is simply a matter of locating the circuit's hot wires (black, red or blue that are connected to the circuit breaker) and the circuit's neutral (white) wire and replacing the circuit breaker in the panel with the AFCI type.
AFCI breakers, like the GFC\I counterparts, have a coiled neutral wire that must be connected to the electric panel's neutral bus.
The hot and neutral circuit wires will all connect directly to the AFCI circuit breaker, and protects the entire circuit from arc faults.
Use AFCI receptacles to provide protection to the circuit only from the point at which the receptacle is installed.
Replace the first non-GFCI receptacle in the circuit with the AFCI receptacle and connect the wires from the panel to the LINE terminals and the wires that continue to the rest of the circuit to the LOAD terminals.
Depending on wiring methods used during construction, this method may not satisfy the requirements of the code.
The AFCI receptacles were much more popular prior to 2008 code, when this protection was required only in bedrooms.
Since then, the code expanded the requirement to include significantly more locations in the dwelling, it seems that manufacturers have begun to produce the circuit breaker instead.
As a result, AFCI receptacles may be more difficult to obtain. -
Step 3: Determine if an exemption applies.
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Step 4: Choose a method of providing protection.
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Step 5: Provide both AFCI and GFCI protection where required.
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Step 6: Add AFCI protection voluntarily.
Detailed Guide
If circuits are installed in a space for use other than a dwelling unit, AFCI is not required (commercial and industrial spaces are not required to have AFCI protection).
AFCI protection is required only in dwelling units (apartments, homes, manufactured homes, RVs and mobile homes).
All 120 volt / 15 or 20 amp branch circuits supplying outlets (includes both lighting outlets and receptacle outlets) in dwelling unit family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sun rooms, recreation rooms, closets, hallways, or similar rooms or areas shall be protected by a listed arc fault circuit interrupter.
This means that nearly every habitable space in new homes are required to have this protection. , Most fire and smoke alarm systems are prohibited from being connected to GFCI or AFCI circuits.
Absent from the list of spaces that require AFCI protection are outdoors, laundry rooms, unfinished basements, attics and garage spaces, to name a few.
Circuits that provide more than 20 amps or more than 120 volts (208 / 240 volts circuits) are also exempted from AFCI protection.
That means most electric ranges, water heaters, clothes dryers, permanently installed electric heaters (baseboard and blower types), artesian well pumps, etc. are exempt because they are supplied by double-pole circuit breakers which puts them on 240 volt circuits and / or rated at more than 20 amps. , AFCI protection is provided by either an AFCI circuit breaker installed at the electrical panel, or by a receptacle specifically identified as providing arc fault protection.
Both the circuit breaker and receptacle are installed similar to the GFCI circuit breakers and receptacles that are present in many homes already.
The circuit breaker method protects the entire circuit, while the receptacle protects only from the point of installation on the circuit, to the end of the circuit.
A caveat for the receptacle method is that it is only considered meeting the code requirements if the portion of the circuit between the electrical panel and the AFCI receptacle is installed in pipe or armored cable and all boxes in the circuit must be metal (the common practice of using plastic / fiber boxes or romex cables would prohibit this solution). , Any required GFCI protected receptacle(s) that are installed in a location that additionally requires AFCI protection (see list above), will have to be AFCI protected as well.
It is possible to install an AFCI receptacle on a circuit protected by GFCI circuit breaker to satisfy the requirement but only if at least the portion of the circuit between the panel and the AFCI receptacle is installed in pipe or armored cable and all boxes in the circuit must be metal (the common practice of using plastic / fiber boxes or romex cable would prohibit this solution).
In this case, install an AFCI circuit breaker and a GFCI receptacle.
The pipe, armored cable, metal box, etc. limitations on AFCI receptacles are not applicable to GFCI receptacles.
Some manufacturers offer circuit breakers that provide both AFCI and GFCI protection in a single package. , Existing installations are not required to upgrade to AFCI protection.
In homes without AFCI devices, the ultimate protection would be to provide AFCI protection throughout the dwelling (except for circuits that have problems with AFCI).
Replace all existing single pole 15 and 20 amp circuit breakers (and any double pole 15 and 20 amp circuit breakers that supply circuits with shared neutrals that provide two 120 volt circuits), or replace the first receptacle on a circuit to an AFCI type to add this protection.
Use AFCI circuit breakers to add arc fault protection to the entire length of existing circuits.
This is simply a matter of locating the circuit's hot wires (black, red or blue that are connected to the circuit breaker) and the circuit's neutral (white) wire and replacing the circuit breaker in the panel with the AFCI type.
AFCI breakers, like the GFC\I counterparts, have a coiled neutral wire that must be connected to the electric panel's neutral bus.
The hot and neutral circuit wires will all connect directly to the AFCI circuit breaker, and protects the entire circuit from arc faults.
Use AFCI receptacles to provide protection to the circuit only from the point at which the receptacle is installed.
Replace the first non-GFCI receptacle in the circuit with the AFCI receptacle and connect the wires from the panel to the LINE terminals and the wires that continue to the rest of the circuit to the LOAD terminals.
Depending on wiring methods used during construction, this method may not satisfy the requirements of the code.
The AFCI receptacles were much more popular prior to 2008 code, when this protection was required only in bedrooms.
Since then, the code expanded the requirement to include significantly more locations in the dwelling, it seems that manufacturers have begun to produce the circuit breaker instead.
As a result, AFCI receptacles may be more difficult to obtain.
About the Author
Teresa Armstrong
Enthusiastic about teaching cooking techniques through clear, step-by-step guides.
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