Where are ARC Fault Circuit Breakers required?

  • A Group Fault Circuit Interrupter (GFCI) was designed to protect people and equipment from electrical shock. An Arc Fault Circuit Interrupter (AFCI) was designed to detect arcing faults in the wiring , appliances and equipment , thereby preventing electrical fires. Two different types of protection in very similar looking devices: read the fine print, check for the NRTL marking.
  • Arc faults arise from a number of situations, including:
    • Damaged-wires
    • Receptacle breakage
    • Neutral leads pinched to grounded metal box
    • Worn electrical insulation
    • Loose electrical connections
    • Shorted wires
    • Wires or cords in contact with vivrating metal
    • Overheated or stressed electrical cords and wires
    • Misapplied/damaged appliances
  • AFCI protection is required to protect the entire branch circuit (with some exceptions for the first section of unspliced cable). Generally, the most cost effective way of achieving this is to installation AFCI circuit breaker in the panel. 
  • Section210.12(A)  lists 5 different methods of achieving code compliance. For new construction, only the first method (combination-type arc-fault circuit interrupter installed as a circuit breaker) is the practical choice. The other 5 choices are viable option, but should only be rarely used.
  • Circuit coverage's are computed the same way as always (3VA per square foot of dwelling area served: 220.12,220.14(J). A 15 amp circuit at 120 volts can supply 1800 VA. AT 3 VA per square foot this yields 600 square feet of floor area per required general lighting load circuit. This combines both room lighting outlets and general purpose receptacle outlets. Several rooms can be3 combined onto one branch circuit. There are no upper limits on the number of general duty receptacles on anyone branch circuit in dwelling units.
  • Old Code: a Combination AFCI (CAFCI) delivers 5 kinds of protection:
    • 1) Parallel protection - Just like its Branch/Feeder counterpart, Combination AFCI can detect and neutralize parallel arc faults.
    • 2) Series Protection- A series arc fault is the unintended flow of electricity over a gap within a single wire. Theses arc faults were not detectable until advanced technology allowed the development of the Combination AFCI breaker.
    • 3) Ground protection- Arcing between a single conductor and aground line.
    • 4) Overload protection.
    • 5) Short circuit protection.
  • Old code AFCI breakers are still out there. Be sure your AFCI breakers are Combination AFCI (CAFCI) breakers.
  • (Combination parallel and series fault, that is) A  parallel fault is an arcing from the hot conductor to either the ground or grounded conductor. Causes include cable staples too tight or a screw or nail too long, which shorts between the cable conductors. A series arcing fault is an open in any current carrying conductor that is arcing. This includes any cords connected to the circuit, brushes in motors in appliances that arc and faulty switches that arc. The newer code compliant CAFCI devices will open the circuit for any of these conditions.
  • While AFCI protection is required for the entire branch circuit, GFCI protection is required only for receptacles can be wired to protect the circuit wiring and receptacles "downstream" from the GFCI receptacle. This is why electricians used the GFCI receptacle whenever possible, it is significantly less expensive.
  • Typically, in the past, electricians would purchase a circuit breaker to protect the conductors, and install GFCI receptacle only where needed. The new code will not allow this anymore, except for lighting and receptacles, accessory buildings and bathrooms.
  • Receptacles in the garage are required by Section 210.52(G) (I) to be fed by a separate circuit, with no other outlets outside of the garage. This means, this circuit may also supply garage lighting outlets, with out AFCI protection, if there are no garage lighting switches inside the house. Of course the receptacle outlets in the garage will still need GFCI protection (210.8(A) (@), and be located at least one per car parking space.

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1. When do I need a permit?
2. I need to have an upgrade or some other change done to my electric service. What do I need to do?
3. What permits do I need to install a pool or spa on private property?
4. Is a permit required for a pool with an inflatable top ring that rises as water is added?
5. Is a permit required for a shed?
6. How long is my permit good for?
7. Can I perform all the work on my own house?
8. Where are ARC Fault Circuit Breakers required?