Re: AFCI Nuisance Tripping #QST

Greydon - KC6SLE

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)

Join to automatically receive all group messages.