Installation techniques for Square D QO CAFI??

[K1GMB]

I'm installing new electrical work for my house, and I have a question regarding the new CAFI's. My house is 37 years old and has the various neutrals in electrical boxes tied together. In some locations in the house, these neutrals are between different electrical circuit breakers. Obviously sharing neutrals between to different circuit breakers won't work with CAFI's which look at the specific individual current outputs from each protection device. OK, so my question is, do I and can I within NEC code treat each circuit as a "dedicated" neutral to the specific device, and NOT tie them together in the electrical box? I don't see an easy solution to this other than treat every CAFI as one protection device, serving only one specific circuit at a time??? Thanks for any suggestions!!!

 

[augie47]

OK, so my question is, do I and can I within NEC code treat each circuit as a "dedicated" neutral to the specific device, and NOT tie them together in the electrical box? ns!!!

yes

 

[K1GMB]

yes

Thanks!!!!!!!

 

[texie]

Unless they are MWBCs they should have never been tied together in the first place. This is one thing that GFCIs and most AFCIs forced people to clean up there act as there was always a lot of this that were never caught.

 

[hbiss]

OK, so my question is, do I and can I within NEC code treat each circuit as a "dedicated" neutral to the specific device, and NOT tie them together in the electrical box? I don't see an easy solution to this other than treat every CAFI as one protection device, serving only one specific circuit at a time?

Not sure what you are getting at. If you are doing new work, why would you repeat the same errors as was done with the original work?

Are you sure you are an electrician?

-Hal

 

[K1GMB]

I'm not attempting to re do what someone else did 37 years ago, I'm just asking was there a better way to work with these new devices? Code says that there are many places (NOT everywhere) where the new requirement is for arc fault protectors. I'm just trying to do it right and safely. If I didn't care and if I didn't have pride in my work, I wouldn't be asking such a highly experienced and respected group that's on this forum. So far everyone has been very professional and extremely helpful. Notwithstanding your question, you obviously didn't understand my initial question, so for that I'm very sorry. Thanks for responding with such informative and helpful advice. Ya must have had a bad day. Cheers

 

[K1GMB]

Unless they are MWBCs they should have never been tied together in the first place. This is one thing that GFCIs and most AFCIs forced people to clean up there act as there was always a lot of this that were never caught.

Yes, you are absolutely correct, and since we brought this house over 25 years ago, I have been finding and correcting various electrical issues as I find and discover them. Issues that clearly should never have been done, and for whatever reason were passed by the county electrical inspector(s). A lot of what I have found over the years are mistakes, but mostly are poor and lazy workmanship stemming back to the electrical installation. Thanks!!!!

 

[ramsy]

I'm not attempting to re do what someone else did 37 years ago, I'm just asking was there a better way to work with these new devices?

Until recently most outspoken members on this forum that couldn't see AFCI's amended out in their State, claimed to rip them out after inspection, without regard for willful construction defect voiding their client's property insurance.

Your desire to comply with this code is extraordinary, relative to the adverse industry reception, or adversity to pay for required labor & skills.

QO AFCI's were supposed to be discontinued, and don't know if 2-Pole versions were ever made for shared neutrals or MWBC's.

For existing buildings, once charcoal wiring & devices are repaired, I find outlet type AFCI's at first opening, or per 406.4(D)4, are simpler & more reliable than AFCI breakers.

 

[K1GMB]

Thanks, Ramsy for your post! Yea, I thought about the outlet type AFCI's, but I thought about this for a while. We recently had new siding installed on the house. While it looks nice, the contractors used very long nails that I discovered recently when we started having intermittent nuisance circuit breaker trips. These nails were piercing the wires in some locations creating momentary shorts which tripped circuit breakers, most of these problems appeared to be in areas where I could cut off the excess carefully with a Dremel tool. This seems to have stopped the nuisance trips, and I am hopeful that this problem has been resolved. Then I thought about the potential of arcing within a wall surrounded by insulation. One of my two main electrical panels were riddled with nails. One nail piercing was less than 1/4" inch from the feed from the outside electrical meter. No over current protection on this. Again, people not paying attention. Another thought that you brought up was voiding the homeowner's property insurance. A very big concern, because in this day and age, Insurance companies are looking for any excuse to void insurance coverage. So, you are so RIGHT about liability. Another specific for me was that I am installing Hubble Type III Surge Arrestor receptacles in areas where I have electronic circuits, in attempts to provide additional surge protection. Thanks again for the feedback!!!! BTW, I didn't know that history about the QO AFCI's, interesting..................Thanks!!

 

[ramsy]

Gratitude is such a refreshing courtesy, it deserves more information.

If more residential-property owner's demanded general-liability insurance from their contractors it would cover resulting damages, and the remodel wiring indicated in your case, with certificate of additionally insured it's covered long after the contractor disappears.

Abatement of damaged wiring is mandated by NEC 110.12(B). Wiring damage is also a construction defect, not legally recognized as repaired by adding AFCI or GFCI protection, neither of which identify glowing connections.

Never let contractors touch your property with an insulation or Megger tester, since thousand(s) of volts can blast your wiring, forcing remodel projects to avoid AFCI skills with existing wiring.

 

[Little Bill]

.

Never let contractors touch your property with an insulation or Megger tester, since thousand(s) of volts can blast your wiring, forcing remodel projects to avoid AFCI skills with existing wiring.

Most insulation testers used for small or residential wiring only go up to 500V. NM is rated at 600V. Besides that, it would take a long duration of overvoltage to do any damage. I minute is usually the duration used on these tests. Granted, anyone using the testers should have experience with them and know how to use them.
To say never let anyone test your wiring is just wrong!
Also, what is "AFCI skills with existing wiring"?

 

[ramsy]

Most insulation testers used for small or residential wiring only go up to 500V. NM is rated at 600V. Besides that, it would take a long duration of overvoltage to do any damage. I minute is usually the duration used on these tests. Granted, anyone using the testers should have experience with them and know how to use them.
To say never let anyone test your wiring is just wrong!
Also, what is "AFCI skills with existing wiring"?

Most 120v devices & appliances are reliably seen destroyed at 240v for very short duration. Few residential contractors do Megger testing, since they wont spend time disconnecting all 120v devices & lighting, much less when occupied.

In-between occupancy, or before 120v devices are installed, 500v Megger testing may be destructive with existing cloth & rubber Type R insulation, built well into the 1960's, or overstuffed wirenuts contacting bonded devices, which worked fine at 120 volts before the Megger test.

Contractors and their monkeys also destroy things just by pulling on it, and can rip 600v wire into shreds, which works fine at 120v for years.

Megger testing doesn't bother me where GL policy claims for remodel wiring can be made by clients, since general liability insurance, or "Certificate of Additionally Insured" is provided before monkey business can trip AFCI or GFCI devices that previously worked fine.

An additional insured endorsement is a provision made to a Commercial General Liability (CGL) policy, that effectively extends the subcontractor or vendor’s coverage to the client (general contractor, real estate owner, hotel management company, etc.), and other relevant parties (lender, joint-venture partner, etc.).

 

[Seven-Delta-FortyOne]

My Insulation Resistance Tester will do 250V.

And anyone who doesn’t understand that you’re supposed to be testing conductors, not devices, shouldn’t be allowed to handle one.