Arc fault breakers

[mike93lx]

Cost aside, any reason not to use arc fault breakers in a house?

I recently had a short in a lighting circuit that I only caught because it took out the LED dimmer. The $600 that it would cost me to swap all of my 120v breakers is peanuts compared to a fire.

Its a 70's house with everything from the cloth covered romex to new work done thus year. When I add something, I try to do home runs, but there are several circuits with quite a few connections, particularly lighting and the receptacles in the bedrooms

I have dedicated circuits for stuff like the fridge, stove (gas), microwave, dishwasher, and a couple going to a bathroom that was just renovated

 

[stickshift]

On a closely related note, what types of devices are likely to nuisance trip an arc fault breaker? Because other than nuisance tripping, arc faults seem like a great idea.

Of course for circuits covering kitchens, bathrooms, garages, etc., you're looking at combination AFCI + GFCI breakers or AFCI breakers + GFCI outlets.

One reason to hold off might be if the technology is improving rapidly. AFCI breakers are a few generations old (?) so maybe the tech is in its mature phase?

 

[AntonLargiader]

Having been through a house fire that was determined to be electrical, I'm pro-AFCI. Have had some Homeline DF breakers for a few years with no issues at all. I have found old wiring in our current house (90 years old) that would have tripped an AFCI had there been one installed.

For me it's not an issue of code or not, it's just a good idea. I feel the same way about GFCI.

 

[u2slow]

Cost aside, any reason not to use arc fault breakers in a house?

I recently had a short in a lighting circuit that I only caught because it took out the LED dimmer. The $600 that it would cost me to swap all of my 120v breakers is peanuts compared to a fire.

Nuisance-tripping drives me nuts.

A normal circuit breaker is supposed to open on a short-circuit.

I live in a 70's house also with dubious electrical changes in the 40 years prior to moving in. Inspection, insurance, and mortgage requirements were fully satisfied. Its still standing right? I correct issues as I find them and carry on.

 

[mike93lx]

Nuisance-tripping drives me nuts.

A normal circuit breaker is supposed to open on a short-circuit.

I live in a 70's house also with dubious electrical changes in the 40 years prior to moving in. Inspection, insurance, and mortgage requirements were fully satisfied. Its still standing right? I correct issues as I find them and carry on.

Nuisance tripping on newer breakers? Or some of the OG stuff? Certainly there must be a cause

 

[ssdave]

..,.,.

 

[ssdave]

....

 

[stickshift]

I've done troubleshooting of "nuisance trips" for several people. Without exception, it was being caused by a particular extension cord or piece of equipment that had a ground fault or arcing contact; the exact thing that the GFCI or AFCI are supposed to detect and trip for.

How did you diagnose the ground fault or arcing contact? Were these pieces of equipment tripping regular breakers?

 

[u2slow]

@mike93lx honestly, it's negative feedback from builder colleagues.. enough that I don't feel the need to spend money to go there. Bigger fish to fry... like moving the last few circuits out of my insurance-approved FPE panel

I've done troubleshooting of "nuisance trips" for several people. Without exception, it was being caused by a particular extension cord or piece of equipment that had a ground fault or arcing contact; the exact thing that the GFCI or AFCI are supposed to detect and trip for.

AFCI is intended as protection for concealed, installed cabling. Mainly fastener penetrations as when these arc, its happening against combustible building materials, and this arcing doesn't draw enough current to trip the OC device.

GFCI is about limiting shock current to the user.

Either device tripping due to a consumer product is secondary.

 

[ssdave]

....

 

[3rdgen]

We have customers who tear them out of their house after we are done , I don't think I would even try and put them in a 50 year old house that just screams trouble. Heres a list of the common problems with find with them.

Back stabbed switches and plug
Microwaves ( panasonic more then others for some reasons)
some fridges and freezers
Some led drivers
Gas water heaters and erv or hrv units
anything with worn brushes
bad extension cords and some power bars
vacuum cleaners because most people are too lazy to bend over and un plug it
have had a few samsung washers
Not sure about all but some arc faults trip to protect themselves from power surges

The worse part is as a contractor we always get blamed, I'm not sure how many people have tried to get us to pay for a freezer full of food because the breakers tripped after a thunderstorm.

 

[u2slow]

I'm not interested in losing the use of 10-30yo appliances and power tools because they were built at a time when a certain amount of leakage current or arc-creation was acceptable - since they were not intended or required to be on any AFCI or GFCI circuit.

GFCI and AFCI do catch some faulty equipment, but for the reasons I stated before, is why they're actually in code.

 

[thammel]

I retrofitted combo arc and ground fault breakers in my 2000 built house. Note that you can NOT use them on MWBC circuits. They will automatically trip. I learned the hard way. So one of my retirement projects is to run separate NM cable to as many of these as I can access. Not a fan of MWBC.

Tom

 

[SarcasticDwarf]

I've done troubleshooting of "nuisance trips" for several people. Without exception, it was being caused by a particular extension cord or piece of equipment that had a ground fault or arcing contact; the exact thing that the GFCI or AFCI are supposed to detect and trip for.

So how exactly to you identify the device causing it? Ex: I have 16 identical LED lights plus a dimmer on a circuit. It trips once every few months. How do you figure it out?

 

[mike93lx]

I'm not interested in losing the use of 10-30yo appliances and power tools because they were built at a time when a certain amount of leakage current or arc-creation was acceptable - since they were not intended or required to be on any AFCI or GFCI circuit.

GFCI and AFCI do catch some faulty equipment, but for the reasons I stated before, is why they're actually in code.

All of my kitchen appliances are brand new, but I am not really concerned about the home run for my microwave or stove. It's the lighting circuits and bedroom receptacles that concern me the most

 

[u2slow]

I retrofitted combo arc and ground fault breakers in my 2000 built house. Note that you can NOT use them on MWBC circuits. They will automatically trip. I learned the hard way.

Very good point to raise.

I am a fan of MWBCs. That's how the utility brings power to your home. Its an efficient use of wire.

 

[mike93lx]

I appreciate everyone's feedback and the discussion, please keep. It coming.

I ordered a 10 pack of 15a breakers, $360 from HD. That will cover all of my existing 15's as well as some 20's that I can change over without a problem, and it will give me protection on the highest risk circuits

 

[mike93lx]

I retrofitted combo arc and ground fault breakers in my 2000 built house. Note that you can NOT use them on MWBC circuits. They will automatically trip. I learned the hard way. So one of my retirement projects is to run separate NM cable to as many of these as I can access. Not a fan of MWBC.

Tom

Good to know

 

[ssdave]

.....

 

[mike93lx]

Inspector here doesn't want AF on any dedicated circuits. He interprets the risk to be on branched circuits, which is probably mostly right. Anything with a home run to the panel, and a single receptacle is exempt. So: washer/dryer, refrigerator, freezer, instant hot water heater, furnace, and similar dedicated circuits are exempt. He also doesn't require AF on Kitchen and Dining room circuits required to have GFCI. So, that takes care of the microwave. He doesn't require AF on the smoke alarm circuit, as long as you don't put any other item on that circuit. He allows a circuit with single outlet receptacles throughout the whole house, for vacuum use. So, it works out well. Last house I built before this one, only had to have AF on the bedrooms, not the whole house. Didn't have any problems with that, except with one vacuum, that we just got rid of. New one didn't do it.

I know others have had problems with AF; I just haven't. So, my early resistance to them has been removed. Would be different if I had bad experiences with them. Every trip I have experienced with them has been related to some sort of an arc from disconnecting something live. Such as pulling out a cord with the motor running.

Not sure why the inspector's opinion matters here. Code is code

 

[ssdave]

......

 

[mike93lx]

The inspector doesn't write the code. I get that it isn't quite that simple, but if they are requiring stuff that isn't codified, they are overreaching regardless of how good the intent is.

I don't care what my Town's electrical inspector's opinion is. He won't be out here at any point anyway, but regardless, code is what matters. He can choose to overlook stuff, but not require above and beyond

 

[AntonLargiader]

..I don't think I would even try and put them in a 50 year old house that just screams trouble.

Because... they might uncover problems? What's so wrong with that? You list backstabbed outlets and defective cords; I just don't understand why you think these issues should be concealed by using standard breakers.

 

[theoldwizard1]

Having been through a house fire that was determined to be electrical, I'm pro-AFCI.

In all my years, you are the FIRST person to say they had residential fire that was electrical related (and not from extension cords) !

IMHO, AFCI and tamper resistant receptacles are just ways for electrical device manufacturers to make more money.

(The only little kid I have ever heard of sticking something into a receptacle is ME !)

 

[theoldwizard1]

I'm not interested in losing the use of 10-30yo appliances and power tools because they were built at a time when a certain amount of leakage current or arc-creation was acceptable - since they were not intended or required to be on any AFCI or GFCI circuit.

GFCI and AFCI do catch some faulty equipment, but for the reasons I stated before, is why they're actually in code.

The GFCI outlet for the washer in my sons remodeled laundry tripped every once in awhile. Very annoying on laundry day. I told him just install a standard receptacle.

My son also has a good friend in the appliance repair business. I was there when he replaced the heating element in the dryer and pre-emptively replaced the belt. He said "Tell your son to never get rid of these (washer and dryer, both over 10 years old) ! It is cheaper to repair them then replace them and the new ones don't last as long and are more expensive to repair !!"

 

[stickshift]

In all my years, you are the FIRST person to say they had residential fire that was electrical related (and not from extension cords) !

https://www.nfpa.org/-/media/Files/News-and-Research/Fire-statistics-and-reports/Building-and-life-safety/oshomes.pdf
Electrical distribution or lighting equipment was the leading cause of home
fire property damage. An average of 35,000 such fires caused 500 deaths;
1,130 injuries; and $1.4 billion in direct property damage per year. Wiring
and related equipment accounted for 7 percent of all home fires and 10
percent of all home fire deaths. Cords or plugs were involved in only 1
percent of the fires but 6 percent of the deaths. Extension cords dominated

NFPA has a report on home electrical fires: https://www.nfpa.org//-/media/Files/News-and-Research/Fire-statistics-and-reports/US-Fire-Problem/Fire-causes/osHomeElectricalFires.pdf
the cord or plug category.

 

[_Stang_]

Square D AFCI in all living areas in our 4 year old new construction home. Had exactly one recurring nuisance trip in those 4 years which turned out to be a wire ever so slightly nicked by an exterior trim nail along an eave.

Sent from my SM-G950U using Tapatalk

 

[dscheidt]

On a closely related note, what types of devices are likely to nuisance trip an arc fault breaker? Because other than nuisance tripping, arc faults seem like a great idea.

Anything that "nuisance" trips an AFCI is defective, assuming a current generation AFCI device. Early stuff was prone to false alarms, modern stuff is much better.

In an old house, you're likely to turn up things like neutrals from different circuits tied together, which will trip AFCIs (and GFCI, for that matter).

 

[stickshift]

Square D AFCI in all living areas in our 4 year old new construction home. Had exactly one recurring nuisance trip in those 4 years which turned out to be a wire ever so slightly nicked by an exterior trim nail along an eave.

Sent from my SM-G950U using Tapatalk

That's cool. Probably never notice that with regular breaker, but still have a nonzero fire risk.

I guess what learned in this thread is that modern AFCI breakers are well designed, and if it's tripping, it's worth tracking down, rather than treat it as a nuisance and constantly reset the breaker or worse, revert to a regular breaker.

 

[stickshift]

In an old house, you're likely to turn up things like neutrals from different circuits tied together, which will trip AFCIs (and GFCI, for that matter).

Why would shared neutrals trip a AFCI-only breaker?

 

[The FIB]

We have customers who tear them out of their house after we are done , I don't think I would even try and put them in a 50 year old house that just screams trouble. Heres a list of the common problems with find with them.

Back stabbed switches and plug
Microwaves ( panasonic more then others for some reasons)
some fridges and freezers
Some led drivers
Gas water heaters and erv or hrv units
anything with worn brushes
bad extension cords and some power bars
vacuum cleaners because most people are too lazy to bend over and un plug it
have had a few samsung washers
Not sure about all but some arc faults trip to protect themselves from power surges

The worse part is as a contractor we always get blamed, I'm not sure how many people have tried to get us to pay for a freezer full of food because the breakers tripped after a thunderstorm.

I'm having issues with electronic ballasts (for low voltage can lights) on a AFCI, not all the time, just every now and then. After googling about the issue, I have found my situation is not uncommon.

 

[arbee]

Square D AFCI in all living areas in our 4 year old new construction home. Had exactly one recurring nuisance trip in those 4 years which turned out to be a wire ever so slightly nicked by an exterior trim nail along an eave.

Sent from my SM-G950U using Tapatalk

How in the world did you find that?

Sent from my SM-G930V using Tapatalk

 

[ssdave]

....

 

[stickshift]

current on the neutral doesn't match the current on the hot, so the breaker interprets a short and trips.

So then why do we need AFCI + GFCI breakers? Per your comment, AFCI-only breaker handles the GFCI function of detecting hot-neutral imbalance.

 

[Chris130]

current on the neutral doesn't match the current on the hot, so the breaker interprets a short and trips.

Why would shared neutrals trip a AFCI-only breaker?

If it's on a properly configured MWBC, it shouldn't. An earlier poster said AFCI breakers don't work on a MWBC, but that's not true...

We've recently remodeled, but for many years, my old kitchen MWBC ran perfectly well on an Eaton-CH 2-pole CAFCI that I installed. And that MWBC had some old wires in fragile condition, but it all worked like a champ.

 

[exranger06]

I retrofitted combo arc and ground fault breakers in my 2000 built house. Note that you can NOT use them on MWBC circuits. They will automatically trip. I learned the hard way. So one of my retirement projects is to run separate NM cable to as many of these as I can access. Not a fan of MWBC.

Tom

You absolutely CAN use AFCI breakers on a MWBC. You simply use a 2-pole AFCI breaker. In fact, that's the entire reason 2-pole AFCI breakers exist, since AFCI is not required on any 240V circuit. Were it not for MWBCs, manufacturers would only have to make single pole AFCI breakers for 120V circuits. You'll also notice that the only AFCI breakers manufactured (single or 2-pole) are 15A and 20A. That's because AFCI is only required on 15A and 20A 120V branch circuits. You won't find any 40A or 60A AFCI breakers.

It's no different than using a GFCI breaker on a MWBC: just use a 2-pole.

 

[exranger06]

My house was built in 1979, so I don't have any AFCI breakers. However, if I add/modify anything electrical, I always bring it up to the latest code. I'm in the middle of adding a new circuit for my "through the wall" window unit air conditioner. It's in the finished basement, so AFCI is required. I bought an AFCI breaker for it. Per 2020 NEC, GFCI is also required in basements, finished or not. I know hardly anyone is using the 2020 NEC already, but like I said, I like to bring everything up to the LATEST code regardless. So, I'll be installing a GFCI receptacle for it too.

 

[stickshift]

If it's on a properly configured MWBC, it shouldn't. An earlier poster said AFCI breakers don't work on a MWBC, but that's not true...

We've recently remodeled, but for many years, my old kitchen MWBC ran perfectly well on an Eaton-CH 2-pole CAFCI that I installed. And that MWBC had some old wires in fragile condition, but it all worked like a champ.

You absolutely CAN use AFCI breakers on a MWBC. You simply use a 2-pole AFCI breaker. In fact, that's the entire reason 2-pole AFCI breakers exist, since AFCI is not required on any 240V circuit. Were it not for MWBCs, manufacturers would only have to make single pole AFCI breakers for 120V circuits. You'll also notice that the only AFCI breakers manufactured (single or 2-pole) are 15A and 20A. That's because AFCI is only required on 15A and 20A 120V branch circuits. You won't find any 40A or 60A AFCI breakers.

It's no different than using a GFCI breaker on a MWBC: just use a 2-pole.

Very cool. I was unaware of the existence of 2-pole AFCI and GFCI breakers.

 

[Showkey]

Anything that "nuisance" trips an AFCI is defective, assuming a current generation AFCI device. Early stuff was prone to false alarms, modern stuff is much better.

In an old house, you're likely to turn up things like neutrals from different circuits tied together, which will trip AFCIs (and GFCI, for that matter).

That’s a great theory..........reality........ is nuisance trips are a problem. So much AFCI are commonly removed after inspection. Are a subject for multiple laws suits with every party pointing at the other the party includes ......the general contractor, electrical contractor, electrical supplier, AFCI manufacturer, power company and the inspector (non govt inspection service).

 

[u2slow]

Electrical distribution or lighting equipment was the leading cause of home
fire property damage....

Who worked on the electrical last - or damaged it? How many homeowners are oblivious to a brewing electrical problem in dated equipment? That's the sort of stuff the stats don't say.

My house was built in 1979, so I don't have any AFCI breakers. However, if I add/modify anything electrical, I always bring it up to the latest code.

I don't know your level of electrical experience, but I hear this frequently. IMHO, a common perspective is that following code precludes the need for permit/inspection or professional oversight. Plus the idea that AFCI/GFCI will effectively audit your work. Code isn't an instruction manual on its own, and the DIYer doesn't always have the depth of knowledge to identify limitations or safety concerns of the existing arrangement, or miss a critical step in the updating.

I'd genuinely like to know what other folks experiences are (mortgage, insurance, eventual inspection) are when major updates have been done without approval. In my experience, the discrete stuff (or shoddy and hidden) goes by the wayside, and the visibly recent updates get called out.