Re: AFCI Nuisance Tripping #QST

Smitty - WB1G

Love it.

I’ve been to the first platform of Sutro, Mt. San Bruno, and Beacon Peak (I think that’s what it’s called), north of the Golden Gate.  I remember a neighbor by Sutro once asking us why his garage door opened randomly.  That was an interesting conversation for sure.

Smitty :)

On May 6, 2022 at 11:51 AM, <Greydon Hicks> wrote:

Yes Smitty, you discovered why I am like I am, too much exposure exposure to electro magnetic fields and other things.

Think you are familiar with Suttro Tower in SF. Can you imagine trying to site and build such a structure and EMF generator today? Friend of mine has to do maintenance in the upper levels of the tower periodically and has to ware a “Faraday” suit.

Years ago debate on low frequency EMF exposure was the rage and media was having a field day with it. But when it was pointed out how much more dangerous higher frequency EMF might be from radio/television/radar/cell phones/etc the media realized what their role in the debate might become, they dropped the subject like a rock.

And recall when the debate over PCB was the big thing. PCB was used to lower the flammability of so many things including insulating oil in electrical devices such a large power transformers and circuit breakers. I have personally been been up to my elbows in PCB treated insulating oil changing tap settings on transformers and adjusting high voltage transmission circuit breakers. Once the potential hazards of PCB was discovered the utility industry worked quickly to remove and properly dispose of it.  But never fast enough for the media. I had to meet one day with a major newspaper publisher in Oakland and update them on how quickly their PCB tainted network transformers were going to be replaced.  Had to sit through 30 minutes of verbal abuse about how bad the utility was for using PCB in the first place. When I finally got a chance to speak I asked them about the half a century plus that they as publishers had been adding PCB to their ink storage tanks to lower the flammability of the ink, ink they then printed on newsprint, newsprint they then distributed to millions of homes and businesses daily, newsprint used to wrap food in, newsprint used to clean windows, newsprint used to package fragile items in, on and on. Dead silence, then one of the newspapers managers commentated: “Oh, you know about that, well, meeting over”.

There is an old saying, “those that live in glass houses should not cast stones”.


Greydon - KC6SLE

On May 6, 2022, at 10:37 AM, Smitty (WB1G) <smittyontheair@...> wrote:

I love all the discussion surrounding the mystery questions.

We had a good chat this morning on the Coffee Break Net about arc’ing and the design of a GFCI’s versus AFCI’s… I also learned that Greydon has an “electrifying  personality” :)

Smitty (WB1G)

On May 6, 2022 at 10:19 AM, <Lisa - KC6SLE> wrote:

Dennis, very good insight and I agree with your assessment.  Having completed many residential wires and rewires, my experiences are similar.  GFCIs have actually become very reliable provided they are of a quality production from a reputable manufacturer.  Arc Fault Current Interrupters, AFCI, however, has not evolved as quickly or as far. Nuisance tripping remains a major consumer issue.

I tend to "over build things".  So some of the technics I use to reduce the negative impact of both GFCIs and AFCIs include:
 - do not put overhead lighting on AFCI areas, bedrooms, or GFCI protected areas, indoor "wet" areas, on the AFCI or GFCI circuits.  I put the lighting in these areas on its own branch circuit.  Bit of an overkill, but does not leave the customer in the dark if the GFCI or AFCI trips.
- I install individual GFCIs at each required location rather than cascading GFCI protection through single GFCIs.  Yes, adds a little cost, but today GFCIs are reasonably priced.  The advantage of doing this is again minimizing the impact of the GFCI trips.

I never had any jurisdictional inspectors or inspections questions or object to doing either of these.

I also only use 20 amp branch circuits, number 12 AWG, as electrical usage, increasing number of appliances, is ever increasing. The benefit far outways the cost over time. 

Steel switch and outlet boxes are more expensive and take longer to properly install and bond, but are infinitely safer should you have a wire nut, receptacle, or switch fail, start arcing and potentially burn.  Just think about an electrical fire within a plastic box. 

Wire nuts...we all use them.  But like all things, there are good and not so good wire nuts out there and please use the right wire nut for the size and number of conductors being joined together. I can't tell you how many times troubleshooting dead circuits I have found failed wire nuts due to either quality or incorrect application. 

Thanks Dennis for continuing the discussion and learning.

Greydon - KC6SLE

On Fri, May 6, 2022 at 9:29 AM Dennis - WU6X <wu6x@...> wrote:
This is an interesting subject for those of you trying to understand the difference between GFI and AFCI, the latter which has been required by the National Electrical Code in all bedrooms of new construction for the last 10 years or so. Supposedly, this prevents an arc caused by a "bed or dresser" getting pushed back against a plug in an outlet behind the furniture. Well, okay ... I submit that fires caused by arcs of this sort are likely very small, and more likely caused by poor or incorrect wiring being done in the first place. California's building inspectors in most cities and counties are more focused on catching common wiring problems, but this is not so in many other states.

For example, while chasing some weird or intermittent electrical issues at a house my Daughter bought in Alabama, I found hot or neutral wires twisted together and taped with black electrical tape, rather than using "wire nuts" as is required here. The ground wires were not "staked" either, simply twisted together and taped. Many of these twisted connections were coming loose and causing lights to flicker or not come on at all, and some plugs were not working at all. Very scary!

A problem I have with AFCI is the breakers are expensive and often cause "nuisance tripping" for the homeowner when using treadmills (common in a lot of bedroom environments), televisions and some fluorescent lights. Home Electrical Products (HEPs) are getting better preventing nuisance tripping, but many products being built in foreign countries (like China) are not paying attention to this issue. And, you wonder why the cost of new homes is going up, with required GFI, solar, AFCI and other things? I sometimes wonder if the manufacturers themselves are coming up with these new devices to increase their revenue.

In summary, some electronic devices simply give AFCI devices problems. Newer generations of AFCI breakers are less prone to problems, but are certainly not immune. There is plenty of information, white papers, etc. about this subject on the Internet.

Dennis - WU6X
(retired General Contractor)



Smitty WB1G

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