What the heck is an AFCI?

It seems like just yesterday that AFCI (Arc Fault Circuit Interrupter) type circuit breakers became required on 120 volt outlets in bedrooms.  It was the year 2002, and there was incredible gnashing of teeth over them.

afcibreakerThere were many who thought they were useless, a waste of money and a burden to the consumer.

There were also complaints of nuisance tripping, after all, what is one to think if every time you plugged in your vacuum and turned it on the breaker tripped.  Certainly there were some bugs to work out and pretty soon it became clear that if the vacuum was tripping there was in fact an issue with the vacuum and not the breaker–the breaker was just doing its job.  Of course some motors were not designed to not emit the kinds of signals that indicated an arcing condition to the brain of the AFCI and adjustments to both the brain and the motors had to be done.

Another issue with the AFCI’s was that it took a couple of years to get even electricians on board as to what an “outlet” was.  Some electricians and even jurisdictional inspectors interpreted the code requirement that all “bedroom outlets” be AFCI protected to mean “receptacle outlets.”  That however, was not what was intended.  An “outlet” can be defined as any place electricity is accessed.  Like lights, smoke alarms, the fans in hydronic heaters or gas fireplaces etc.  Anything that utilizes 120 volts and is located in the bedroom is supposed to be AFCI protected.

I still routinely find some of these 2002 houses with only the receptacles on the AFCI circuit.  By the next code cycle this was clarified and we started to see “all” bedroom outlets on the AFCI circuits.

There was always some question about the efficacy of these early AFCI breakers because they did not provide protection of the wiring for both parallel arcs and series arcs.  A justifiable complaint in my opinion since series type arcs are perhaps one of the most likely causes of electrical fires (like what would occur at a loose connection) and they required relatively high levels of fault current to activate the devices.  But they did pave the way for the “combination type” AFCI that could detect both series arcs (loose connections) and parallel arcs (line to neutral–short circuits).

In 2008 (with a start date of June, 2009) the combination type became required instead of the branch feeder type and they became required in more locations in the home than in just the bedrooms.

Some States, like Washington State, in their infinite wisdom (never underestimate wacky), decided to maintain the requirement for them to only be in bedrooms and amended the NEC to that effect.  This amendment was ignored by the larger cities, like Seattle, Bellevue and Renton where the full requirement of the 2008 National Electrical Code is enforced.  In brand new construction in Seattle, it is now common to run into service panels with many of these AFCI breakers–instead of just the bedroom circuits.  Now, as of 2014, AFCI’s will be found protecting the outlets in kitchens, laundry rooms, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, or similar rooms or areas.

All of this represents some problems for the home inspector—we have to be conscious of the jurisdiction we are inspecting in.  Of course inspectors have always had to take the jurisdiction they are inspecting in into account.

How does the inspector share this information with their client?

Obviously it will vary depending on the house.  A pre-2002 house is pretty simple, we can ignore the issue (not a good idea in my opinion) or we can inform our clients that the overall fire safety of the home can be improved by the installation of AFCI breakers.  This of course is going to be greatly affected by the existing condition of the wiring in the home.  For example some panels won’t have room for them and of course if the house has an old fuse panel it becomes even more complicated.  Certainly in the context of a service change they should be added and the older the wiring is, the more benefit that can be derived by their presence.

For houses built between 2002 and 2009, the inspector might want to consider recommending upgrading the older style “Branch/Feeder” type AFCI’s to the safer  “Combination Type” AFCI’s.

Obviously the client would not be “required” to upgrade, but I still consider it a good recommendation–and then let the client decide.  I also like this approach because there were some recalled breakers during this time period that will automatically be eliminated if they are upgraded.

For a much more enlightened and thorough treatise on AFCI breakers please visit Douglas Hansen’s, AFCI’s Come of Age.

 

By Charles Buell, Real Estate Inspections in Seattle

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What are Daisy Chained & Back-Stabbed Receptacles?

Daisy chaining is the practice of running wires from receptacle to receptacles via either back-stabbing (sticking the wires in holes in the back of the receptacle—left of picture)  or using the screws on the side of the receptacle (center of picture).

(could be switches as well but for now we will discuss receptacles)

This is a poor practice, especially the back-stabbing approach, as every connection can result in voltage drop such that by the time you get to the end of the circuit the voltage drop affects the function of whatever is plugged in. 

The side screw type daisy chain is not quite as problematic but with that method if something goes wrong with one receptacle it would affect any others downstream from the problem one.

Different ways to wire a receptacle

A better practice is to wire-nut the wires together in the box, and then run a pigtail to the receptacle (right side of picture)—doing this for the ground wire, the “white” (neutral) wire and the “black” (hot) wire (sometimes the colors vary for the hot conductor).

The pigtail method is considered “best practice” but is obviously more labor intensive and therefor more expensive to have done.

Better modern receptacles also have plates with screws where the wires insert without bending and are tightened behind plates under the screw–this should not be confused with back-stabbing. 

With back-stabbing there is a sharp upward sloping barb that prevents the wire from pulling out and this is the entire connection–the amount that sharp barb grabs onto the wire.  This type of connection is especially problematic with aluminum wiring.

By Charles Buell, Real Estate Inspections in Seattle

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What is that dang bare copper or aluminum or green ground-wire for anyway?

The grounding/bonding wire.

This poor wire is a bit schizophrenic.  It has different names depending on where it is terminated and many people accuse it of doing things it is not responsible for. 

dscf7009For example when we run this wire to our house grounding electrode system (ground rods, Ufer grounds, metal water pipe etc) we call it a GEC, or Grounding Electrode Conductor.  When we run it from switches, receptacles, lights and other points of use to our electrical panels we call it an EGC, or Equipment Grounding Conductor.  The two uses are tied together as if they were “one” in your electrical service equipment (your main panel). 

This leads to considerable confusion over what it actually “does.”

In simplistic terms, the GEC (grounding electrode conductor) is a path to dissipate static charges and surges safely back to the earth via the ground rods, Ufer ground, or metal water pipe it is attached to.

The EGC (equipment grounding conductor) serves two functions:

  1. It provides an effective ground fault current path to trip a breaker or blow a fuse in the event that there is a short to the metal components being bonded.
  2. It provides a path to earth to dissipate static charges and surges that would otherwise build up on the electrical system.

There is a myth that is pervasive among home inspectors, and even some electricians, that the equipment grounding conductor is there to prevent shock.  There is another even more serious myth that all electricity is trying to go back to earth and this is how it gets there.  It is really best to forget both of these myths if one is to stay safe.

The reason for the confusion is that if there is a “short” to the grounded metal components and the circuit is tripped off, one obviously can’t get a shock from something that is turned off.  The dangerous aspect of this is that the metal components can be energized up to the amperage of the circuit (and even beyond) without tripping the breaker and a person touching the metal components would still get a shock.

If the person happened to be touching the grounded metal component at the very time the fault occurred, they could still get a shock–albeit a very short one.  It still could be enough to arrest one’s heart or scare one off a ladder resulting in possible serious injury.  So in this respect the equipment grounding conductor is not a true shock protection component of the system.

Obviously with no ground wire at all we have no chance of shutting of the equipment in the event of a short and we do actually increase the chance of getting shocked.  The solution is not just to install the ground wire–because that will only improve the situation–not eliminate the risk.

To reduce the risk of shock we must install GFCI protective devices, either as receptacles at points of use or as circuit breakers that protect the whole circuit.  We do not even need a ground wire to gain this protection.  The GFCI devices do not need a ground to function and this is why they are so important and valuable on older homes without equipment grounds until the systems can be upgraded.

The most critical thing to remember when you are working around live wires is as long as you do not contact grounded metal components and are physically isolated from the actual earth (not standing barefoot on concrete or kneeling on the wet ground) you have pretty much zero chance of getting a shock when you touch an energized component.  Of course if you touch the neutral and hot wires you will indeed get a shock.  Because we might make a mistake or not realize when we are grounding ourselves, we install GFCI devices to take care of us.

It is best practice to never assume metal components are not energized.

By Charles Buell, Real Estate Inspections in Seattle

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