New AFCI Rules Expand Protection for Branch Circuits
The purpose of the National Electrical Code (NEC) is the practical safeguarding of persons and property from the hazards arising from the use of
electricity. Arc-Fault circuit interrupter (AFCI) protection has been one of the effective ways to accomplish this goal.
The AFCI device is intended to provide protection from the effects of arc faults by recognizing characteristics unique to arcing and by functioning
to de-energize the circuit when an arc fault is detected. De-energizing the circuit before an arc fault that can cause a fire is a key preventative measure for the protection of life
AFCI protection for branch circuits supplying laundry rooms is required. Even though the number of fires caused by arc-faults in
laundry rooms is only about 4% of the number of reported electrical fires, expanding the use of AFCI protection is a very effective means to further reduce the potential
for fires as a result of an arc-fault. Such protection is afforded either by means of a listed combination type AFCI to provide protection for the entire
branch circuit or by a listed outlet branch circuit type AFCI installed at the first outlet to protect the circuit downstream,
In dwelling units, additional protection of 120 volt, single phase, 15- and 20-ampere branch circuits supplying kitchens could have
protection form arc-faults.
Although incremental steps in expanding AFCI protection have been taken eventually we may see whole house AFCI protection.
Still another requirement requires AFCI protection for branch circuits supplying devices as well as outlets. There are several instances where a branch
circuit supplies a lighting outlet that is in an area that does not require AFCI protection. However, the switch that controls the lighting outlet is in an
area such as a bedroom that does require AFCI protection. The inclusion of devices in addition to outlets supplied by branch circuits will clarify that the branch circuit in such
areas also requires AFCI protection. AFCI’s must be installed in a readily accessible location.
Additional areas are afforded AFCI protection to provide safeguards that can save lives at a relatively low cost.
The NEC does not prohibit a receptacle outlet from being installed above a
suspended ceiling, typically for maintenance purposes to plug in hand held portable tools. However, it should be noted that where the space above the suspended ceiling is considered other spaces for environmental air as specified in 300.22(C), the wiring methods and equipment must be installed as required by that section.
Therefore, even in a residential application where NM cable typically would be permitted, because it is a space used for environmental air 300.22(C) prohibits the use of NM cable.
Section 400.8(5) prohibits flexible cords and cables from being installed above suspended or dropped ceilings whether used for return air or not for any type of premises or application. These rules limit the use of materials that would contribute smoke and products of combustion during a fire in an area that handles environmental air.
Additionally, cords are prohibited from being installed above a suspended ceiling in all cases to comply with 400.8(5) and with 400.8(1) which prohibits the use of flexible cords and cables as a substitute for the fixed wiring of a structure. Restrictions on the use of flexible cords through and above suspended ceilings were first introduced in the 1999 NEC. Part of the reason for this revision is in concert with the language that has been in the NEC for several editions in 410.30(C) then 410.62(C) that permits cord-and-plug connection of electric-discharge luminaires only when the flexible cord is visible for its entire length. Any cord installed through and or above a suspended ceiling is not visible for its entire length. Flexible cord located out of site such as behind suspended ceiling panels is subject to damage or fatigue which would notbe readily detected. Some suspended ceilings are made of metal thereby increasing the potential for damage.