# The benefits and disadvantages of AFCI protected circuits



## jar546 (Jul 19, 2013)

I believe that AFCI technology is a wonderful step forward for fire protection.  I also believe that it is better served for usage in existing buildings with older wiring.

I think there is a downside, however, such as nuisance tripping.  This is especially true in voltage drop situations such as a powerful vacuum cleaner with a 16A motor on 1 25' #16ga cord.

Is the cost vs benefit worth it for new construction considering where the code is today?


----------



## Gregg Harris (Jul 19, 2013)

jar546 said:
			
		

> I believe that AFCI technology is a wonderful step forward for fire protection.  I also believe that it is better served for usage in existing buildings with older wiring.I think there is a downside, however, such as nuisance tripping.  This is especially true in voltage drop situations such as a powerful vacuum cleaner with a 16A motor on 1 25' #16ga cord.
> 
> Is the cost vs benefit worth it for new construction considering where the code is today?


There are some interesting studies that have been conducted that show AFCI is not all it was purported to be.


----------



## gfretwell (Jul 19, 2013)

I still believe there is a lot of snake oil in the AFCI (proprietary) detection methods. Ground faults are a very mature and easily defined technology but the AFCI was rushed into the code before the technology really even existed. They are being developed and beta tested in our homes at the point of a government gun.

We are at something like version 3.0, what recourse do the people have with the earlier versions that are inferior to the new ones since they were forced to buy them and promised that they provided more protection than they do.


----------



## Uncle Bob (Jul 19, 2013)

Mike Holt, the god of electricians; explains arc fault protection;  Arc Fault Protection: What it’s all About.  I vote for number 6 (bottom of page).  The only reason afci s are required is to feed the electrical manufacturer's insatiable appetite for profits.  The Proles (mindless masses of the book 1984) have no choice but to submit and the mindless puppets called inspectors (me) have no choice but to enforce.  The manufacturing gods have spoken.  Ten years from now home buyers will be required to become certified by a home safety course before they can own a home.  This crap called capitalism is out of control.  Uncle Bob


----------



## peach (Jul 19, 2013)

I vote for #6, too.. even with new wiring, they trip.  With old wiring, it's worse.  The last time I checked the Mike Holt forum, it seemed the majority of the contributors were saying.. not required on old branch circuits.


----------



## Paul Sweet (Jul 20, 2013)

The feds (Consumer Product Safety Commission) are behind AFCIs.  They worked with Cutler-Hammer to develop them.  Their intent was to introduce them gradually, than ramp up the requirements until all 15 & 20 amp circuits in residences must be AFCI protected.

I believe they would be of more benefit on older wiring that might have deteriorated insulation, and are of minimal value on new construction.


----------



## gfretwell (Jul 20, 2013)

I think you have that backward. My neighbor was on the team that developed the AFCI at C/H and I got the impression they came up with the idea and lobbied CPSC and NFPA to create a market for it.


----------



## ICE (Jul 20, 2013)

This was taken from the Mike Holt link that Bob provided.  So far, the only type that I have seen is a circuit breaker.  According to the description of Branch/Feeder AFCI, it doesn't detect a series arcing fault.  But then the last paragraph states that UL 1699 requires that series arc faults will be detected.



> Arcing faults can occur in one of two ways, series arcing faults or parallel arcing faults, but the most dangerous of these is the parallel arc. A series arc can occur when the conductor in series with the load is unintentionally broken. Examples might be a frayed conductor in a cord that has pulled apart or a loose connection to a receptacle or in a splice. A series arc is load limited, such that arc current cannot be greater than the load the conductor serves. Current with an arc in series has a lower rms value than current without the arc due to extinction and re-ignition. Typically, series arcs do not cause enough heat to create a fire.Parallel arcing faults either occur in two ways, either a short circuit or a ground fault.
> 
> Short-Circuit Arc. A short circuit arc might occur if the wire insulation is cut by a staple or a cord is cut by a metal table placed on it. The current flow of a short-circuit arc is only limited by the system impedance and the impedance of the fault itself. A ground fault arc can occur only when a ground path is present, and this fault can be cleared by either GFCI or AFCI protection device. The rms current value for parallel arc faults, will be considerably less than that of a solid fault, and a typical 15 A might not clear this fault before a fire is ignited.
> 
> ...


----------



## north star (Jul 20, 2013)

*# = = = #*

*I too am of the opinion that the "great life safety benefits" **of the AFCI rated breakers are not what they were
marketed to be.

Uncle Bob,  ...I will respectfully disagree with you on the statement of "the manufacturing gods have spoken".
While I DO believe that they have lobbied hard to market their products [ in this case the AFCI rated breakers  ]
in to the various codes, ...we, as code officials, CAN also lobby the various AHJ's where we are employed or
have influence,  to amend that requirement out of the adopted codes.........Here's the catch though !......We code
officials will have to lobby & educate harder than the manufacturers did to get them in to the codes......We
[ code officials  ] should not just simply roll over and do nothing !

Amend the AFCI requirements out and let the manufacturers market their products in another **market, ...not yours*
*or mine !     *

*# = = = #*


----------



## Daddy-0- (Jul 21, 2013)

Glad that Virginia uses......wait for it......common sense and amends at least some of the stuff out that makes little sense. We have limited requirements for AFCI for instance. Only required in a few places like bedroom circuits.


----------



## electriclese (Jul 21, 2013)

Bedrooms only here in Pueblo, for now anyways.

I agree #6. Businesses have to show growth so why not mandate specifications that require new hardware that can help boom China's economy.


----------



## Dennis (Jul 21, 2013)

I will say that the use of afci on new construction has made many electricians go back and find fault with their installs.  Personally I have found them to work fairly well and have just a few issues with them.  The main problem is vacuums, TV's (and accessories) and ceiling fans but usually only the cheaper fans.


----------



## jwelectric (Jul 21, 2013)

Arc-Fault has been around for a while now. George Spencer who started testing for parallel arcs back in the early 1980s and worked for Zlan is the push behind this technology not the manufacturers of the product.

If one would read the replies to the newsletter at the Holt site they would see Mr. Spencer’s reply.

I am very AFCI pro and believe that most of the problems that electricians are exercising are due to their lack of knowledge on how to install an electrical system not the devices they are installing.

The practice of all neutrals in a box goes together is one of the biggest problems found with AFCI circuits.

Yes there are some cheap appliances out there that causes problems with these devices but with the mandate of their use these items will slowly disappear.

Being in the trade for more years than most here are old I remember when GFCI was mandated way back in 1968 for pools and the same crying took place back then that I am hearing today about AFCI.

In 10 to 20 years no one will give them a second thought just as GFCI today.


----------



## jar546 (Jul 21, 2013)

Dennis said:
			
		

> I will say that the use of *afci on new construction has made many electricians go back and find fault with their installs.*  Personally I have found them to work fairly well and have just a few issues with them.  The main problem is vacuums, TV's (and accessories) and ceiling fans but usually only the cheaper fans.


I would agree.  I think that many of the complaints were due to actual problems.  Here is a case in point:

A lady was referred to be due to her frustration over a tripping AFCI circuit for the master bedroom.  It was a new house recently C/O'd and the electrician had 3 call backs for nuisance tripping AFCI.  He eventually gave up and said that this was a problem with the AFCI's and they should not be required and this was a perfect example.  In total frustration, she called my office and I agreed to go out and troubleshoot the problem by the hour.

The circuit in question was the master bedroom that also fed the fan/light combo in the master bathroom.  In the master bedroom, it ran the lighting and receptacles.

There was only 1 light off a switch directly over the bedroom, the rest were plugged in lamps along the side of the bed

There was 1 small television plugged in.  No other equipment other than an alarm clock was plugged into this circuit.

Whenever you plugged in a simple tester to a receptacle, it tripped the AFCI breaker.

You could turn the light on and off without tripping it most of the time but if there was a load on one of the receptacles, it would trip the AFCI.

I started with the basics and swapped AFCI units with no change in results.

I then disconnected the master bath light/fan with no change.

I pulled every single receptacle and switch out of the wall with no change.

I then painstakingly megged the hot and neutral wires by methodically removing devices from the circuit.  All was good.

I also ran resistance checks from hot to neutral, ground, etc. with all normal results.

I was sure that there was going to be a staple behind a wall somewhere that was damaging NM but none of the tests could determine that.

Finally, there was one last box that I needed to access.  The light above the bed.  It was a large, heavy, oak king bed with little room to move it anywhere.  After moving all of the furniture I was able to access the light fixture.  It was a porcelain single incandescent temporarily in place until they decided what ceiling fan they wanted.  This is where I found the problem.

The electrician did not ground the ceiling fan rated box and the equipment ground wire was hanging down, almost touching the exposed neutral terminal on the back of the fixture.  It was not touching it but close enough to create an arc when there was enough load coming through the neutral which was a pass through for other parts of the system.  This explains why all of the megger and resistance checks looked good.  That was it.  I grounded the box and pushed the ground up and out of the way and the problem was solved.

So yes, I agree that AFCI's have discovered problems from electrician mistakes.


----------



## peach (Jul 21, 2013)

Thanks Jar.

It was great that you had the time and equipment to do the testing.  HOWEVER, most of us can't do this.  Was a grounding/bonding pigtail not installed in the box?  Green to green isn't a mystery.


----------



## jar546 (Jul 21, 2013)

peach said:
			
		

> Thanks Jar.It was great that you had the time and equipment to do the testing.  HOWEVER, most of us can't do this.  Was a grounding/bonding pigtail not installed in the box?  Green to green isn't a mystery.


The box was not grounded be the NM-B that fed it so the ground screw was not installed, nor was there a clip.

Porcelain fixtures for single bulbs do not have a ground wire unless they are a combo for a 3 prong receptacle.

I had the time because I charged by the hour to troubleshoot the problem and have a background as a master electrician.  It was not my jurisdiction so I felt is was OK to do so.


----------



## RIchardr888 (Nov 10, 2021)

Uncle Bob.  You must be one of those who did not enjoy civic's class. Capitalism, normally implies free market, does not regulate. What you're describing is crony capitalism.  The more the people need help or the more help that's offered to the people is accepted than the greater stupid regulations will be enacted by government leaders and their rich pals.  Capitalism fixes problems whereas government control designs problems.  You like the government hope their citizens are so dumb they can't understand what's being told them.


----------



## steveray (Nov 10, 2021)

I miss UB.....


----------



## Paul Sweet (Nov 10, 2021)

We all miss him.


----------



## Rick18071 (Nov 10, 2021)

Not many problems here with arc faults. Usually the electrician takes the arc-faults out after the C. O. and saves them for the next job.


----------

