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Arc fault breakers

AntonLargiader

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Who worked on the electrical last - or damaged it? How many homeowners are oblivious to a brewing electrical problem in dated equipment?

What does it matter? It is the way it is at that moment and if the AFCI is picking up an arcing break that's going to set something on fire, THAT is what matters. Sure, in a perfect world workmanship is perfect and nothing deteriorates unexpectedly. AFCI and GFCI are for the imperfect side of things, which is real enough that our standards have taken it into account.

And following latest code, what's wrong with that? If the powers that be have decided that a GFCI recep is appropriate in location X and I'm replacing a recep in location X, I get ridiculed for choosing a GFCI? I don't think so.
 
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exranger06

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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 never said that I didn't need an inspection, and I never said that I wasn't getting an inspection. I also never said AFCI/GFCI would audit my work. All I said was that I bring stuff up to the latest code, even when it's not required. There's nothing wrong with going a little above and beyond the minimum. My town is following the 2017 NEC, so AFCI is required for my new circuit, but GFCI is not. I'm installing a GFCI anyway, because why not? Even if my area isn't following the 2020 NEC right now, they will be within the next few years, so I like making my installs as "future-proof" as possible.

As for my experience, I have a bachelor's degree in electrical engineering and I work as an engineer for an electric utility. Which I admit is not the same as being a licensed electrician, but it does show that I know a thing or two about electricity. I have a lot of experience in residential wiring, and I read the NEC for fun. Everything I do is up to code and I've never had a problem passing an inspection.
 

u2slow

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What does it matter? It is the way it is at that moment and if the AFCI is picking up an arcing break that's going to set something on fire, THAT is what matters. Sure, in a perfect world workmanship is perfect and nothing deteriorates unexpectedly. AFCI and GFCI are for the imperfect side of things, which is real enough that our standards have taken it into account.

And following latest code, what's wrong with that? If the powers that be have decided that a GFCI recep is appropriate in location X and I'm replacing a recep in location X, I get ridiculed for choosing a GFCI? I don't think so.

Point one - it skews the stats. Lighting circuits are commonly and easily abused. (fixture changes, ceiling fans, confusing switching arrangements, and/or mixed with receptacles.) Its also where conductor insulation temperature ratings of early NM cable were found to be deficient. AFCI will likely catch a branch circuit problem like this. Distribution side problems are upstream without AFCI protection.

Point two - nothing wrong with it, if done properly. Direct upgrade for one receptacle to GFCI can be easy, or not. Box fill? Pigtails? Line/load implications? Any bond/EGC wire? Half of the old receptacle switched?

What I'm more getting at is more extensive concealed work (i.e. kitchen reno). Are folks being required to expose work for proper inspection, or does it just go by the wayside? (as I've experienced with previous-owner hackwork.)
 

u2slow

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I never said that I didn't need an inspection, and I never said that I wasn't getting an inspection. I also never said AFCI/GFCI would audit my work. All I said was that I bring stuff up to the latest code, even when it's not required.

Sorry - I didn't say you did either, because I didn't presume to don't know your expertise.

I'm trying to share and dispell some backward thinking that's getting too popular amongst some DIY acquaintances I have.
 

stickshift

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What I'm more getting at is more extensive concealed work (i.e. kitchen reno). Are folks being required to expose work for proper inspection, or does it just go by the wayside? (as I've experienced with previous-owner hackwork.)
I would assume this kind of branch circuit work goes by the wayside. If home inspectors were holding up every sale for non-permitted branch circuit work (new outlets, LED lights, etc.) that's not noticeably flawed and appears up to code, the housing market would grind to a halt.

I'd be curious to hear what guys in the trades have to say.
 
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_Stang_

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How in the world did you find that?

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Electrician who wired the house and remembered how he ran everything, inside access to the eave in a storage cubby hole and a wee bit of luck.

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egdede

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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

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.

Good to know

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.


Siemens (bought Murray) makes Double pole AFCI that can MWBCs without fail. I have never had a nuisance trip on my arc-fault breakers in 10 years even when running a HF jackammer that throws sparks out of the motor compartment. They have to be working because they trip when I push the test button, right? ; )
 

ddawg16

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I've been using AFCI's since 2012. I have not had a single false trip....even when using my miter saw or skillsaw.

I did get a trip when I installed a gfci on one of the ckts. I eventually found out I had a broken wire at the back of the box....about 3 inches from the end. The AFCI did it's job.

It was a ***** fixing that wire
 

thammel

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So If I buy double pole breakers for my 7 MWBC circuits, and these are Square D QO type, at about $115 each, gonna be real expensive!!
 
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mike93lx

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So If I buy double pole breakers for my 7 MWBC circuits, and these are Square D QO type, at about $115 each, gonna be real expensive!!

Makes it not so helpful to run a MWBC anymore

The breaker cost is a little more than half for two separate breakers
 

AntonLargiader

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I don't think MWBCs were ever advantageous breaker-wise because standard single-pole breakers are dirt cheap. Most of them are around $5, which is more or less free in the grand scheme of things. Hard to economize on that.
 
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mike93lx

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I don't think MWBCs were ever advantageous breaker-wise because standard single-pole breakers are dirt cheap. Most of them are around $5, which is more or less free in the grand scheme of things. Hard to economize on that.

The difference was at least much less
 

Wiz02

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Just wanted to thank ssdave for the list of inspector preferences in post 21. Most of those items are good practices, even if not required by code, and I typically follow these preferences, but then again, I don't make a living doing residential wiring.

I am an electrical engineer by degree, and do all my own electrical. That being said, my professional work years ago was designing electronics, not power and now I write software. However, I do read and understand (most of the time) the NEC and follow the advice of knowledgeable professionals. I too have no issues with inspections but where I live it's 2014 and a couple of years ago when I wired my external garage, it was 2011(at least as far as the NEC was concerned).

Ever hear the joke if the end of the world is imminent where do you want to be? Answer is Pennsylvania where everything is 20 years behind.

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86turbodsl

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Michigan
I had to install AFCI on my home build in 2007-2009. I did the wiring myself and i am a neat freak. Nail plates on everything, very careful wiring. The electrical inspector came in and just smiled on my panel as he passed me. I had issues with nuisance trips on a couple of breakers. I removed them after COO approval only those couple though. Like a lot of other things, there's probably some truth on both sides of the issue.
 

ddawg16

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I had to install AFCI on my home build in 2007-2009. I did the wiring myself and i am a neat freak. Nail plates on everything, very careful wiring. The electrical inspector came in and just smiled on my panel as he passed me. I had issues with nuisance trips on a couple of breakers. I removed them after COO approval only those couple though. Like a lot of other things, there's probably some truth on both sides of the issue.

My inspector made a comment after my inspection....he asked me if I had any trips and I told him No...then he said "Most people pull them out and replace with regular breakers"
 

thammel

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Maryland
I need to clarify myself. I tried to use a combo GFCI/AFCI breaker on a MWBC circuit and it would not work. I found out that because of the common neutral wire this presents a problem with this type of breaker, which I like to use. I just looked at square D website and I don't believe they make a two pole combo breaker (perhaps for this very reason). So this is why I am planning on running new wire to as many MWBC circuits as I can to get rid of them.
 

stickshift

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northeastern US
I need to clarify myself. I tried to use a combo GFCI/AFCI breaker on a MWBC circuit and it would not work. I found out that because of the common neutral wire this presents a problem with this type of breaker, which I like to use. I just looked at square D website and I don't believe they make a two pole combo breaker (perhaps for this very reason). So this is why I am planning on running new wire to as many MWBC circuits as I can to get rid of them.
Square D does make two pole AFCI and two pole GFCI breakers.
https://www.homedepot.com/b/Electrical-Power-Distribution-Electrical-Panels-Protective-Devices-Circuit-Breakers-Double-Pole-Breakers/Square-D/CAFCI/GFCI/N-5yc1vZbm1eZal2Z1z0mh9uZ1z0mhac?NCNI-5

Not sure about 2 pole AFCI/GFCI breakers.
 

AntonLargiader

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Charlottesville, VA
I looked previously and I didn't find any 2-pole DF breakers. I did find AFCI and GFCI separately in Homeline, CH, and Leviton. Could be that DF is just not made because if they're not required by code not enough people will buy them.
 

BombShelter

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Nov 16, 2015
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State of Hockey
I'm on the outside looking in, literally, working outside of the home. We've been on remodelling sites where the box has been upgraded with arc-faults and it can be really tough if not impossible to do work with corded tools. Our equipment is not old, but mixers, pumps and SDS drills will all easily pop the breakers. This is a common issue with the arc-fault homes and doesn't seem to be isolated. Upgrade if needed but keep a spare set of normal breakers handy if you need to do work with any corded tools.
 
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