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You need a AFCI in most places now. In the 2020 edition of the NEC®, Section 210.12 requires that for dwelling units, all 120-volt, single-phase, 15- and 20-amp
by tibbon 4y ago
You need a AFCI in most places now. In the 2020 edition of the NEC®, Section 210.12 requires that for dwelling units, all 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices installed in dwelling unit kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, or similar rooms or areas shall be protected by AFCIs.
The latest National Electrical Code requires both AFCI and GFCI protection only in kitchens and laundry rooms, but if you're already doing AFCI, why not do it all everywhere as it is clearly to be required at some point
Main downside is they are expensive. I've recently installed a new 24-slot subpanel and I'm using them everywhere required. At $50 a pop, that's a quick $1200.
- londons_explore 4y agoSome countries you have a single one for the whole building, rather than one per circuit. That dramatically lowers the cost. The only real downside is that if you accidentally put your finger in the toaster, rather than just the power to your kitchen cutting off, the power to the whole house cuts off. I think thats a fine tradeoff to save $1200.
- chaosite 4y agoWell, if the power shuts off and that saves me from electrocuting myself, I couldn't care less how much of the rest of the house lost power. The annoying part is when I plug in some faulty device that is not immediately dangerous and that shuts down power to the whole house.
- techie128 4y ago> The annoying part is when I plug in some faulty device that is not immediately dangerous Do you mind, re-reading that statement? I don't even understand that argument. You should not be plugging in faulty devices in the first place...
- jrockway 4y agoI guess you don't know if it's faulty until you try to use it. Manufacturing defects are a thing, but kind of a once every 30 years type thing, so maybe not a big deal to worry about. The reason you install circuit breakers and AFCIs is to avoid a fire in these cases; rare, but worthwhile to avoid.
- Spivak 4y agoAlso because plugging in faulty devices into outlets is something that ought to be safe. Because with probability 1 it will happen in every house. If the way the house is wired makes the only safe action to shut everything off that's the problem and shitty wiring.
- midoridensha 4y agoExactly: it's just like computer OSes. You should be able to run a faulty program that divides by zero or dereferences a null pointer without the whole computer crashing. The computer should flag the error, tell you what went wrong and why, and let you continue with your work and the other stuff going on in other windows. Fault-tolerance is an important and useful thing.
- chaosite 4y agoOf course I should not be plugging in faulty devices. But sometimes appliances that were fine before break down, perhaps some insulation broke down or just the ravages of time. I would absolutely like that to be safe. And like I said, if it's immediately life-saving, then I don't mind the power to the whole house being cut. But if it's "just" a bad appliance, then, well, I do find it a bit annoying that it reset all my electronics, and I would have preferred it if only that specific outlet was effected. But I would still very much like the protection.
- abakker 4y agoreal downside: many things work poorly on gfci stuff. E.g. A miter saw or welder. I had AFCI/GFCI breakers in my garage per code, but essentially no power tools work with those kinds of circuits.
- UI_at_80x24 4y agoI've noticed the same thing with a cheap lemon juicer in the kitchen. I'm assuming the brushes on the DC motor are the cause.
- wlesieutre 4y agoThe bigger downside is nuisance tripping because the breaker doesn't like electrical noise emitted by some device or another in your house. I don't have any AFCIs but I've heard it's pretty common. You'd rather have one circuit go out instead of the whole house, and if all you have is the one AFCI breaker you're going to have a much harder time identifying what device(s) is the culprit.
- tibbon 4y agoI've mostly used them on new circuits, but have put them on a few of my older circuits too. For my small sample size, I've yet to have one nuisance trip.
- pxx 4y agoYeah I've replaced all of the breakers (to living areas) in my 90s home with AFCI ones. Haven't had any nuisance trips. If I had "nuisance trips" I'd be more worried about my wiring than about my breakers...
- mcbishop 4y agoThis nuisance tripping is the bane of my electrician friend's professional life.
- Spivak 4y ago"Oh just err on the site of extremely cautious and sensitive. More safety can't be a bad thing."
- wlesieutre 4y agoAnd god forbid you use anything with a brushed motor, which has sparks in its normal operation
- JKCalhoun 4y agoSome OS's have a single task for the whole computer, rather than one per application. The only real downside is that if your app accidentally dereferences NULL, rather than just your application crashing, the whole computer crashes. ... Sorry, somehow reminded me of the early days of the Macintosh's OS before it was "true multitasking" (as the Amiga kids would love to tell us).
- anikom15 4y agoDon’t even get me started on AFCIs. At least the behavior of GFCIs is well-defined. The AFCI thing is a money grab.
- jxramos 4y agowhy's that, is there some guarantee they fail to live up to? Is there something probabilistic to them or something?
- londons_explore 4y agoAFCI's are of dubious effectiveness at their purpose (preventing fires). They're kinda snake oil because each manufacturer won't tell you under what exact conditions they'll trip. Somehow the law in the USA now requires them on every circuit, although they aren't used at all in Europe (which has a higher voltage yet far fewer electrical deaths).
- amluto 4y agoThere are other downsides. For example, actually finding a two-pole or AFCI breaker or, worse, a combination AFCI/GFCI breaker is not so easy.
- Wohlf 4y agoI recently installed some new circuits and was able to find them, but strangely it was $20 or more per circuit cheaper to get an AFCI/GFCI outlet and a regular breaker instead of combo breakers.
- abakker 4y agoit is nearly impossible, IME. Good luck finding AFCI 20amp 2 poles for doing shared neutral 120v circuits on a 14/3 wire.
- giantg2 4y ago"At $50 a pop, that's a quick $1200." See, this is the part I hate. I bet someone patented the design, then the NEC made it mandatory, and now they just rake in the money on something that likely costs <$10 to make. If something is legally mandatory, it should not be patented.
- xxpor 4y agoLooks like you're not wrong: https://patents.google.com/patent/US9577420B2/en https://patents.google.com/patent/US9577420B2/en
- samsa 4y agoMichigan is an exception. No AFCI required.
- polski-g 4y agoAFCI trips on the smallest thing. Turning on my blender or microwave tripped it. I ended up downgrading to just GFCI in frustration.
- zbrozek 4y agoBrushed motors in particular are largely indistinguishable from an arc fault. Lots of home motors (in vacuum cleaners, fans, blenders, food processors, garbage disposals, blah blah blah) use them.
- mturmon 4y agoNot an electrician, but an observer of tradespeople at r/electricians. There are definitely bad feelings about these AFCI breakers. The feeling is that the code mandate for AFCI got out front of the reliability of actually-produced AFCI's, and actually-in-use products like blenders that may have small "arcing". This results in expensive call-backs from unhappy customers who are getting nuisance trips.
- phpisthebest 4y agoIs there a site that show what states have adopted what version? looking at my states webpage the official adopted code for my state is NFPA 70 - National Electrical Code, 2008 Edition.