Testing old wiring before arc fault protection

[dhalleron]

I read in another post where someone tracked down a wire fault using a megger and it got me thinking.

I don't have much experience with arc fault breakers, but a friend of mine says he has a lot of problems with them when used on old romex. He even had a recent problem with a brand new circuit connected to a brand new refrigerator.

What are the chances of this working: Use existing wiring in a house built in say 1959, replacing all the devices and fixtures and using a combination arc fault ground fault breaker. If the wiring passed a megger test could it be assumed to work fine for a while?

The above example is for bedroom and living room wiring without a ground. The kitchen has a ground wire. I wondered if we could replace all the non grounding type receptacles with grounding type and protect it with the combo breaker. Any thoughts?

Thanks

 

[mopowr steve]

The most likely reason your friend has issues using arc fault breakers with older Romex was that it was commonplace for different circuit neutrals to be all tied together (usually in switch boxes) which would cause the ground fault function of the breaker to trip.

Recently on a new home had a trouble call about the refrigerator tripping afci. Reported the problem to the Afci trouble website and they responded to the fact that the particular brand refrigerator LED lighting inside was the culprit. And that the engineers were working together to resolve.

As far as installing a combo breaker, I think you may need to stand corrected and say "dual purpose" breaker as this is the breaker that has both class-A gfci protection and combination afci protection in one unit. Saying combo breaker could be misconstrued as a combination series/parallel afci only.

Installing "dual purpose" breaker should make you legal beagle.

 

[ActionDave]

Recently on a new home had a trouble call about the refrigerator tripping afci. Reported the problem to the Afci trouble website and they responded to the fact that the particular brand refrigerator LED lighting inside was the culprit. And that the engineers were working together to resolve.

That's what you get with AFCIs.

 

[iwire]

But our NEMA friends said they work great. One even claims they don't false trip.

 

[ActionDave]

But our NEMA friends said they work great. One even claims they don't false trip.

I started out believing that. I really thought the problem was everybody else.

It wasn't till I had my own nuisance trip on a new house, caused by a power tool that I came to my senses.

 

[ptonsparky]

I started out believing that. I really thought the problem was everybody else.

It wasn't till I had my own nuisance trip on a new house, caused by a power tool that I came to my senses.

Now Dave, that was not a nuisance trip. The device was performing as designed...you know that. Repeat "Not a nuisance trip." Repeat again, with some conviction this time.

 

[bphgravity]

But our NEMA friends said they work great. One even claims they don't false trip.

So, the UL 1699 standard for AFCIs has roughly (50) different performance tests. Once you strip away the "standard" tests done on ALL electrical devices that ensure the product is safe from shock, fire, damage, etc.; what you are left with are primarily performance tests to prevent unwanted tripping.

For instance you have:

> Overvoltage, Undervoltage, Voltage Variations & Surge Voltage Tests (Ring Wave & Combination Wave)
> Loading Condition Tests (Inrush Current, Normal Operating Arcing, Non-Sinusoidal Waveform, Cross-Talk, Multiple Load, Lamp Burnout)
> Operation Inhibition Tests (Signal Masking, EMI Filter, Line Impedance)
> Resistance to Environmental Noise Tests (Electrostatic Discharge, Electromagnetic Field, Electrical Fast Transient, Induced RF Fields)

And there are a few others.

In order for a household refrigerator or freezer to be listed to the UL 250 standard, they must also go through a series of performance tests to ensure they do not operate outside any of the parameters set within that standard while under a host of varying conditions. None of those parameters are permitted to exceed the thresholds of the unwanted tripping tests in the UL 1699 standard for AFCIs.

A refrigerator is nothing more that a few motor loads, lighting loads, and perhaps a few electronic loads. None of the operational characteristics of these types of loads are subject to unwanted tripping IF they perform to standard.

One of three issues must be occurring in order for an AFCI to trip on a branch circuit supplying an outlet connected to a refrigerator:

1. The AFCI is damaged or defective.
2. The refrigerator is damaged or defective. (Any one part or component)
3. The wiring &/or terminations are defective.

That's it. The rest is simple algebra. If the AFCI and refrigerator are to standard, the wiring is the culprit. If the AFCI and wiring are to standard, the refrigerator is the culprit. If the refrigerator and wiring are to standard, the AFCI is the culprit.

 

[iwire]

So, the UL 1699 standard for AFCIs has roughly (50) different performance tests. Once you strip away the "standard" tests done on ALL electrical devices that ensure the product is safe from shock, fire, damage, etc.; what you are left with are primarily performance tests to prevent unwanted tripping.

For instance you have:

> Overvoltage, Undervoltage, Voltage Variations & Surge Voltage Tests (Ring Wave & Combination Wave)
> Loading Condition Tests (Inrush Current, Normal Operating Arcing, Non-Sinusoidal Waveform, Cross-Talk, Multiple Load, Lamp Burnout)
> Operation Inhibition Tests (Signal Masking, EMI Filter, Line Impedance)
> Resistance to Environmental Noise Tests (Electrostatic Discharge, Electromagnetic Field, Electrical Fast Transient, Induced RF Fields)

And there are a few others.

In order for a household refrigerator or freezer to be listed to the UL 250 standard, they must also go through a series of performance tests to ensure they do not operate outside any of the parameters set within that standard while under a host of varying conditions. None of those parameters are permitted to exceed the thresholds of the unwanted tripping tests in the UL 1699 standard for AFCIs.

A refrigerator is nothing more that a few motor loads, lighting loads, and perhaps a few electronic loads. None of the operational characteristics of these types of loads are subject to unwanted tripping IF they perform to standard.

One of three issues must be occurring in order for an AFCI to trip on a branch circuit supplying an outlet connected to a refrigerator:

1. The AFCI is damaged or defective.
2. The refrigerator is damaged or defective. (Any one part or component)
3. The wiring &/or terminations are defective.

That's it. The rest is simple algebra. If the AFCI and refrigerator are to standard, the wiring is the culprit. If the AFCI and wiring are to standard, the refrigerator is the culprit. If the refrigerator and wiring are to standard, the AFCI is the culprit.

Lots of words yet still they are causing contractors and homeowners lots of headaches without any proof they are saving lives or property.

But as long as there is profit to be made I am sure we are stuck with them.

 

[ActionDave]

So, the UL 1699 standard for AFCIs has roughly (50) different performance tests. Once you strip away the "standard" tests done on ALL electrical devices that ensure the product is safe from shock, fire, damage, etc.; what you are left with are primarily performance tests to prevent unwanted tripping......

And once you get out of the office and down in the trenches you find AFCIs tripping when UL listed equipment is plugged in. That's the reason each manufacture has an AFCI hotline, no?

Get rid of the nuisance tripping issue and there is still no evidence that AFCIs do anything to prevent fires in homes. There is no evidence that 120V can sustain an arc and AFCIs do nothing to stop a glowing connection.

 

[dhalleron]

I think you may need to stand corrected and say "dual purpose" breaker.

Thanks for the correction.

So do you think if the old wire is verified not to be sharing neutrals with other circuits and tests clear with a megger, will it stand up without nuisance tripping? I'm shopping for my first megger now. Saw lots of good suggestions on this board.

 

[K8MHZ]

Thanks for the correction.

So do you think if the old wire is verified not to be sharing neutrals with other circuits and tests clear with a megger, will it stand up without nuisance tripping? I'm shopping for my first megger now. Saw lots of good suggestions on this board.

There is no guarantee an AFCI will not nuisance trip. You can have a PERFECT wiring system and the AFCIs can still trip when your neighbor transmits on his perfectly legal amateur radio.

I am also with the crowd that believes they do not add any safety over what a GFCI will do.

 

[GoldDigger]

I am also with the crowd that believes they do not add any safety over what a GFCI will do.

Or those who believe similarly but specify both a GFCI and a low magnetic trip threshold.

 

[ptonsparky]

FWIW, we have installed AFCIs in the last couple homes we put new services on. My thought was to check for problems first. My help let the AFCIs do the testing. If it tripped they chased down the problem. No problems since other than an extension cord that showed trouble as an Arc. Did it keep the house from burning or save a life? Who knows.

 

[klineelectric]

I recently responded to nuisance tripping on a new install we did. Breaker was tripping once a week. Told homeowner on phone before I went (spent) to troubleshoot to unplug everything on circuit to see if it still trips.(still under warranty) I showed up to house and she had 4 antique lamps plugged into bedroom circuit, along with an afci loving surge strip with wifi router and other electronics. Needless to say she did not unplug anything before I got there. Since I was already there I pulled breaker removed bulbs and disconnected ceiling fan and fluorescent light and unplugged everything. I than meggered circuit and got a 1 (good) reading on all of my wiring. I than meggered all 4 of her lamps. One of the lamps tested good, 3 did not. The worst lamp had a reading of 250-300. So in this instance afci got it right but I have had a few refrigerators and bath fans nuisance trip. What do you tell homeowners than?

 

[peter d]

I recently responded to nuisance tripping on a new install we did. Breaker was tripping once a week. Told homeowner on phone before I went (spent) to troubleshoot to unplug everything on circuit to see if it still trips.(still under warranty) I showed up to house and she had 4 antique lamps plugged into bedroom circuit, along with an afci loving surge strip with wifi router and other electronics. Needless to say she did not unplug anything before I got there. Since I was already there I pulled breaker removed bulbs and disconnected ceiling fan and fluorescent light and unplugged everything. I than meggered circuit and got a 1 (good) reading on all of my wiring. I than meggered all 4 of her lamps. One of the lamps tested good, 3 did not. The worst lamp had a reading of 250-300. So in this instance afci got it right but I have had a few refrigerators and bath fans nuisance trip. What do you tell homeowners than?

More than likely it was the GFP portion of the AFCI breaker that was "finding" the fault, not the actual arc logic.

 

[klineelectric]

More than likely it was the GFP portion of the AFCI breaker that was "finding" the fault, not the actual arc logic.

Very true! Only impossible to tell because even with their infinite wisdom and superior intellect the manufacturers cant give us a proper tester to show that there is an actual arc fault. I wonder why.........because they are probably all ground faults.....except of course for the "nuisance trips" (and don't tell me the intelli arc is a proper tester)

 

[JFletcher]

A little off-topic, but what kinds of arcs will trip AFCIs? Will small arcs, like those caused by loose light bulbs, loose terminal screws on switches and receptacles, bad connections under wirenuts, worn out switches being operated, and pulling a cord and plug out of a receptacle while the equipment is energized (like a vacuum cleaner cord being inadvertently yanked out while its running), cause AFCIs to trip?

 

[ActionDave]

A little off-topic, but what kinds of arcs will trip AFCIs? Will small arcs, like those caused by loose light bulbs, loose terminal screws on switches and receptacles, bad connections under wirenuts, worn out switches being operated, and pulling a cord and plug out of a receptacle while the equipment is energized (like a vacuum cleaner cord being inadvertently yanked out while its running), cause AFCIs to trip?

No. None of those things arc enough to trip an AFCI.

 

[romex jockey]

More simple math for you....

More simple math for you....

1. The AFCI is damaged or defective.
2. The refrigerator is damaged or defective. (Any one part or component)
3. The wiring &/or terminations are defective.

That's it. The rest is simple algebra. If the AFCI and refrigerator are to standard, the wiring is the culprit. If the AFCI and wiring are to standard, the refrigerator is the culprit. If the refrigerator and wiring are to standard, the AFCI is the culprit.

4. Everything is perfectly complaint, but because it's proximal to the serving Xformer, the refer motor exceeds the afci 75A mag trip.

~RJ~

 

[ptonsparky]

4. Everything is perfectly complaint, but because it's proximal to the serving Xformer, the refer motor exceeds the afci 75A mag trip.

~RJ~

So now we need to put a line reactor ahead of the service or move the house further back on the property? Sounds reasonable.