Arc fault breaker

[ramsy]

Since the fire cause and origin data that was used to show the need for AFCIs showed that about 85% of the dwelling unit fires said to be of electrical origin were in units over 20 years old, they probably won't be functional when needed anyhow.

Would not expect 20 years without surge protection. Same goes for GFCI breakers in service equipment, with front-row seats to utility excursions.

Even with surge protection, if test signal could still trip the breaker, I've found test buttons frozen, perhaps from outdoor temperature changes. Pushmatic was my first experience with breakers that seize up in outdoor equipment. Somehow, expansion & contraction of switches & buttons in outdoor enclosures ruin breakers with tight tolerances.

 

[ramsy]

Since the fire cause and origin data that was used to show the need for AFCIs showed that about 85% of the dwelling unit fires said to be of electrical origin were in units over 20 years old, they probably won't be functional when needed anyhow.

Regarding data showing probability of electrical fires increasing with time, it makes sense since more construction defects can be installed. Even if unmolested by remodelers & flippers, enough time finds vermin or water damage to electrical equipment.

What doesn't make sense is why AFCI's would need 20 years to work in new buildings.

When unqualified persons let the smoke out, all it takes is a trace carbon deposit across Neutral to Grounding terminals for that AFCI high-impedance N-G trip function. Even if sparking & arcing carries on without tripping, the AFCI trips when smoke in the box deposits a high-impedance trace across N-G terminals.

 

[don_resqcapt19]

Regarding data showing probability of electrical fires increasing with time, it makes sense since more construction defects can be installed. Even if unmolested by remodelers & flippers, enough time finds vermin or water damage to electrical equipment.

What doesn't make sense is why AFCI's would need 20 years to work in new buildings.

When unqualified persons let the smoke out, all it takes is a trace carbon deposit across Neutral to Grounding terminals for that AFCI high-impedance N-G trip function. Even if sparking & arcing carries on without tripping, the AFCI trips when smoke in the box deposits a high-impedance trace across N-G terminals.

Not that they would need 20 years to work, just that dwelling unit fires that are said to be of electrical origin are much more common in units over 20 years old. If you have one million new dwelling units with 100% AFCI protection (code does not require 100% protection) and you assume that the AFCI will prevent 100% of the electrical origin fires (something that no one claims is possible), you would expect to prevent about 50 fires in a year. If you have the same conditions in 0ne million dwelling units over 20 years old, you would expect to prevent about 285 fires in a year.

As far as the carbon tracking, there are a number of AFCIs on the market than no longer have any type of ground fault detection circuit, so they won't be detected until there is an arc. The device only looks for parallel arcing signatures when the current exceeds 75 amps and series arcing signatures where the current exceeds 5 amps.

 

[ramsy]

As far as the carbon tracking, there are a number of AFCIs on the market than no longer have any type of ground fault detection circuit, so they won't be detected until there is an arc.

Perhaps high-impedance continuity, including from carbon deposits, describes it better than carbon tracking.

 

[ramsy]

The device only looks for parallel arcing signatures when the current exceeds 75 amps and series arcing signatures where the current exceeds 5 amps.

Since AFCI's trip when touching N-G to different fingers, this high-impedance trigger is an empirical trip function of AFCI's.

 

[ramsy]

If you have the same conditions in 0ne million dwelling units over 20 years old, you would expect to prevent about 285 fires in a year.

Unless all other factors are controlled, that statistical analysis tells us nothing. All factors that affect electrical fires must be account for, before making conclusions about any one factor.

 

[ramsy]

AFCI's are certainly a barrier to market entry, since they require a specialized skill set incompatible with the exploit of unskilled labor.

That barrier to entry should discourage labor shops & unqualified persons from pursuing residential-electrical permits, except of course in States where labor shops lobby with their chamber of commerce to amend out the AFCI barrior.

 

[letgomywago]

AFCI's are certainly a barrier to market entry, since they require a specialized skill set incompatible with the exploit of unskilled labor.

That barrier to entry should discourage labor shops & unqualified persons from pursuing residential-electrical permits.

But it doesn't work when someone completely botches the job.

 

[don_resqcapt19]

Since AFCI's trip when touching N-G to different fingers, this high-impedance trigger is an empirical trip function of AFCI's.

But many of them no longer do that. All of the original branch circuit/ feeder type AFCIs had a ground fault function, but a number of the combination ones on the market now have eliminated that function. None of the GE or Siemens ones and some of the Eaton ones have eliminated that function.

 

[don_resqcapt19]

Unless all other factors are controlled, that statistical analysis tells us nothing. All factors that affect electrical fires must be account for, before making conclusions about any one factor.

There is not much data out there, but the data that was used to say AFCIs are needed, showed that 85% of the dwelling unit fires that were said to be of electrical origin occurred in dwelling units over 20 years old.

There is no way to control any of the factors, as there is no uniform fire cause and origin investigation requirements. Few dwelling unit fires are investigated by a trained fire investigator. Most are just reports filled out by the fire company officer, and there is pressure not to show the cause as "unknown".

 

[ramsy]

But many of them no longer do that. All of the original branch circuit/ feeder type AFCIs had a ground fault function, but a number of the combination ones on the market now have eliminated that function. None of the GE or Siemens ones and some of the Eaton ones have eliminated that function.

Next time changing a light, with switch off, touch Neutral & Grounding with different fingers. It will trip any connected AFCI protective device.

It does not matter if 30mA GFPE is included with C/AFCI or not. Human-body resistance varies, but it trips all brands of AFCI breaker and outlet types. This differs from bolting N-G together, which does trip Class-2 GFCI's, not sure about GFPE.

Since impedance implies current flow, allow me to reword my earlier statement:

Since AFCI's trip when touching N-G to different fingers, this resistance trigger is an empirical trip function of all types of C/AFCI.

 

[letgomywago]

Next time changing a light, with switch off, touch Neutral & Grounding with different fingers. It will trip any connected AFCI protective device.

It does not matter if 30mA GFPE is included with C/AFCI or not. Human-body resistance varies, but it trips all brands of AFCI breaker and outlet types. This differs from bolting N-G together, which does trip Class-2 GFCI's, not sure about GFPE.

Since impedance implies current flow, allow me to reword my earlier statement:

Since AFCI's trip when touching N-G to different fingers, this resistance trigger is an empirical trip function of all types of C/AFCI.

Try with a GE afci they've had no gfpe for 10 years or so

 

[ramsy]

Try with a GE afci they've had no gfpe for 10 years or so

Human body resistance connected Neutral to Grounding (N-G) will not trip a GFCI, only bolted N-G connections trip a GFCI, or connections from Hot to Grounding.

 

[retirede]

Human body resistance connected Neutral to Grounding (N-G) will not trip a GFCI, only bolted N-G connections trip a GFCI, or connections from Hot to Grounding.

 

[macmikeman]

As far as the carbon tracking, there are a number of AFCIs on the market than no longer have any type of ground fault detection circuit, so they won't be detected until there is an arc. The device only looks for parallel arcing signatures when the current exceeds 75 amps and series arcing signatures where the current exceeds 5 amps.

I had this the opposite way around apparently.
For quite some time I have been under the impression it was 5 amps parallel and 75 amps series, making the series function almost useless since a 75 amps series arc is going to probably cause some combustion at a much lower level than 75 amps , being on the order of a cooking coil up on the top of a range oven or something similar. Now I have to reconsider my whole outlook on the arc fault circuit breakers.

 

[macmikeman]

Next time changing a light, with switch off, touch Neutral & Grounding with different fingers. It will trip any connected AFCI protective device.

It does not matter if 30mA GFPE is included with C/AFCI or not. Human-body resistance varies, but it trips all brands of AFCI breaker and outlet types. This differs from bolting N-G together, which does trip Class-2 GFCI's, not sure about GFPE.

Since impedance implies current flow, allow me to reword my earlier statement:

Since AFCI's trip when touching N-G to different fingers, this resistance trigger is an empirical trip function of all types of C/AFCI.

Now I am going to have to try this trick with Eaton non dual use just to check it out. Never witnessed it on any afci breaker so far. Eaton non dual use certainly won't trip out when a Knopp solenoid type voltage tester is applied between the hot conductor and the ground , so it is clear they have no gfci circuitry , whereas a lot of other brands (and I am certain GE is one of them , will trip out when a Knopp tester is applied between hot and the equipment ground wire with the power on to the circuit. But this test with the switch off between neutral and ground for an instant trip is overwhelmingly going to stick in my brain now and I almost can't wait for the work week to start..............

 

[macmikeman]

I'm really happy I visited this thread today, just like that you can learn something new .

 

[letgomywago]

If it won't I wonder what will lol

 

[don_resqcapt19]

Next time changing a light, with switch off, touch Neutral & Grounding with different fingers. It will trip any connected AFCI protective device.

It does not matter if 30mA GFPE is included with C/AFCI or not. Human-body resistance varies, but it trips all brands of AFCI breaker and outlet types. This differs from bolting N-G together, which does trip Class-2 GFCI's, not sure about GFPE.

Since impedance implies current flow, allow me to reword my earlier statement:

Since AFCI's trip when touching N-G to different fingers, this resistance trigger is an empirical trip function of all types of C/AFCI.

That is not a function of any combination type AFCI. It is not something that the arc signature recognition algorithm looks for.

 

[ramsy]

That is not a function of any combination type AFCI. It is not something that the arc signature recognition algorithm looks for.

The N-G resistance trigger is an empirical trip function of all C/AFCI's