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Posts Tagged ‘National Electric Code’

How old are your smoke detectors? When was the last time you tested them?

November 4th, 2011 No comments

The home heating and holiday season is approaching so now is a good time to inspect your smoke detectors and carbon monoxide detectors to make sure they are in proper working condition.  It’s also a great time to consider having a professional electrician upgrade your smoke detectors to meet the current safety standards and local codes.

Ninety-six percent (96%) of all homes in the US have at least one smoke detector according to a 2010 National Fire Protection Agency (NFPA) sponsored telephone survey.  But, only 75% of the homes in the US have a working smoke detector.  According to NFPA data from 2005-2009, smoke detectors sounded in only half (50%) of the fires reported to US fire departments and almost two-thirds (66%) of home fire deaths resulted from fires within homes with non-working or no smoke detectors.  Twenty-four percent (24%) of the deaths occurred in homes that had smoke detectors installed, but the detectors failed to sound.

Smoke detector installation code requirements are governed by the National Fire Alarm Code, NFPA 72.  Prior to 1993, smoke detectors were governed by NFPA 74.  The code requirements have changed over time, with the goal being the improvement of personal safety by providing earlier warning of fires through the home’s smoke detectors.  Prior to 1989, single, stand-alone battery operated smoke detectors were required to be installed in homes or in new construction.  In 1989, newly constructed homes were required to have interconnected (hardwired) smoke detectors on every level of the home and outside of sleeping areas.  With inter-connected detectors, all the units would sound if any one detector triggered and alarm.  In 1993, the code was revised to include a requirement for the hardwired smoke detectors to be in every bedroom or sleeping area in addition to the units on every floor.  In 1996, the code requirements were modified to require the hardwire smoke detectors also have battery back-ups to ensure operation during power outages.  This battery back-up must be able to maintain power to the smoke detector for a period of seven (7) days after the low battery warning begins to sound.

While governed by NFPA 72, smoke detectors are also covered or addressed in the National Electric Code (NEC).  The 2002 NEC saw a major revision with the new requirement of Arc Fault Circuit Interrupters for all bedroom circuits including lighting and smoke detector receptacles.  Local codes and local jurisdictions have overridden the NEC in many areas over concerns that nuisance tripping of AFCI circuits can leave the bedroom unprotected if the battery back-up fails.

Both the NFPA 72 and NEC require that smoke detectors have visible Power-On indicators (usually green LEDs) and be supplied by either a dedicated branch circuit or the unswitched portion of a branch circuit for power and lighting.  The NFPA 72 and NEC prohibit the use of a GFCI to supply power to smoke detectors.

Most electricians will strongly recommend that older homes or those built before the adoption of the 2002 NEC, should have the smoke detectors updated to meet the new code requirements and be installed on a dedicated, interconnected circuit with a smoke detector on all floors and detectors in all bedrooms or sleeping areas.  In addition, most electricians also recommend the addition of a hardwired, interconnected Carbon Monoxide detector with battery back-up be added the smoke detector alarm circuit near the furnace and hot water heater.  Alarm strobe lights are highly recommended for families with individuals that are hard of hearing or hearing impaired to alert them of alarm conditions.

 A parting tip:

Always change the back-up batteries in all smoke detectors or carbon monoxide detectors on your birthday and test the detectors at least four times a year, at the change of each season.  This ensures that the batteries are always in good condition and ready to offer the extended coverage in the event of a power loss.  Also, if you do experience and extended power loss for more than a day or two, it’s recommended that the batteries in all smoke detectors be replaced to ensure they are in top condition for the next power loss.  Batteries are a small price to pay to ensure the safety of you and your loved ones.

 

For additional information on the NFPA or NFPA 72, please visit the NFPA’s web site at:
http://www.nfpa.org/categoryList.asp?categoryID=278&URL=Safety%20Information/For%20consumers/Fire%20&%20safety%20equipment/Smoke%20alarms

Arc-Fault Circuit Interrupters… say what?

July 20th, 2011 No comments

AFCI Circuit Breakers

 

AFCI breakers are Arc-Fault Circuit Interrupters.    They are similar in appearance to GFCIs (Ground-Fault Circuit Interrupter) breakers and they first came into the market in 1999. They are designed to prevent fires from arcs (sparks) that are not a normal part of a circuit’s operation.  Normal and safe arcs occur in switches and in electric motors such as fans and vacuums.  They are generally very small or very short in time duration.  The devices that produce these normal small arcs are designed to shield and protect people as well as the surroundings from the arcs so there is no fire risk.  Dangerous arcs can occur when devices fail, cords are damaged or the wiring becomes faulty as often happens with receptacles using stab-in connections.

The original AFCIs were branch type units designed to trip on 75 amperes of arcing current from the line wire to either the neutral or ground wire.  They were required to be installed for all bedroom circuits with the 2002 National Electric Code but did not provide personal protection from ground faults so kitchens, bathrooms, and garages still required GFCI circuit protection.

The 2008 revision of the National Electric Code changed the requirements to include Combination Type AFCIs for all 15A or 20A circuits in a dwelling except kitchens, bathrooms, laundry rooms and unfinished basements, which still require GFCI protection.  The combination AFCI added additional protection for series arcing at 5A and personal ground-fault protection which trips the breaker at a 5mA level for ground faults while maintaining the original 70A parallel rating for line to neutral arcing.  AFCIs still protect the circuits from the traditional overloads, short circuits and overheating breakers.  The Code still does not require AFCIs for kitchens, laundry areas, bathrooms and garages since it requires the use of GFCI breakers or GFCI receptacles in these locations.  Adding AFCI breakers to feed GFCI receptacles is not recommended due to the fact that nuisance tripping can frequently occur.

All of the major manufacturers offer combination AFCI breakers so replacing older standard breakers with the new combination AFCIs is possible in all but a small percentage of applications.  The primary exception being the “cheater” breakers that feature two circuit in one mounting position that are typically used when a smaller load center has no spare positions for mounting new breakers.   Local jurisdictions and local codes vary, so always contact your local officials or local electricians for assistance.

On a final note, if the wiring in your home does not have the combination AFCIs and you have them added for the additional fire protection they offer, contact you r home owner’s insurance agent and let them know your electrical panel was updated.  You may qualify for a lower annual premium or other discounts which can help offset the cost of the upgrade.