AFCI BERAKER

[kwired]

Propane, Hydrogen and methane would be the exception?

Now add oxygen to the mix.

 

[mbrooke]

Now add oxygen to the mix.

Yup, you have a point here.

 

[peter d]

Talking about AFCI sub mains is capitulating to the AFCI racket. Instead, we should be putting our energy into having AFCI rules rescinded and removed from model codes. I'm hoping that the powers that be are taking notice of these threads, and that you know we are on to your AFCI scam.

 

[user 100]

Now add oxygen to the mix.

:thumbsup:

 

[kwired]

Talking about AFCI sub mains is capitulating to the AFCI racket. Instead, we should be putting our energy into having AFCI rules rescinded and removed from model codes. I'm hoping that the powers that be are taking notice of these threads, and that you know we are on to your AFCI scam.

I don't think those that matter the most are paying much attention. I do think the manufacturers have deep enough pockets to keep presenting them with material to convince the CMP of what they want them to know about the topic, even if the right intentions are somewhere behind it, they are still pushing a product that is not yet acceptable for the user.

 

[don_resqcapt19]

Propane, Hydrogen and methane would be the exception?

Those would probably result in a deflagration and not an explosion. While the damage effects are much the same, the difference is the speed of the propagation with a deflagration having a propagation speed less than the speed of sound and an explosion having a speed greater than the speed of sound.

 

[peter d]

Well, that's too bad you feel that way. My employer doesn't dictate who I am personally and professionally. My personal and professional ethics would never be compromised by my own profit motive or of that of the NEMA member companies I represent. My service to the electrical industry is above reproach.

Put your money where you mouth is. Go ahead and criticize the industry that employs you, and we'll see just how true that is.

Manufacturers have to provide safe and effective products to make money and a profit. Not a single NEMA member company wants an electrical product they manufacture result in the loss of life or property or NOT work to prevent the loss of life and property. The (4) manufacturers of AFCI breakers and the (4) manufacturers of AFCI receptacles have an impeccable history of providing safe, reliable, and cost effective products dating back to the dawn of the electrical industry.

So you're saying that the manufacturing industry is perfect, and has never made a defective product. Are you sure you want to hang your hat on that?

Is it fair to say that contractors seek to make money and profit alone, and nothing else? Is it fair to say electrical instructors seek to make money and profit alone, and nothing else? Of course not. We ALL want to make a good living while providing a valuable service to the communities we serve.

Agreed, but that's not the issue here. Contractors, instructors, etc don't have the luxury of making a product and then having that product mandated into use by legislation. We don't get to profit based on having standards and laws written in our favor.

I can't put my finger on exactly why you are so angry and negative about the electrical industry, but it is certainly directed at the wrong people...

It's pretty simple - I don't like being forced to use worthless, expensive products at the point of a gun. As Don has said many times, the original AFCI introduction by the manufacturers was based on a lie. Why should I trust them after that when they did nothing to remedy that? As for the "wrong people", you've stood up and defended AFCI's, so you're fair game as far as criticism goes.

 

[topgone]

Those would probably result in a deflagration and not an explosion. While the damage effects are much the same, the difference is the speed of the propagation with a deflagration having a propagation speed less than the speed of sound and an explosion having a speed greater than the speed of sound.

There is a table for determining whether the explosive concentration for any gas is achieved. Fuels explode when the right oxygen-fuel ratio is present and a spark is initiated. There is an LEL (lower explosive limit) and an UEL upper explosive limit). Any gas concentration below or above said limits will "probably not" explode . Here is a sample from NFPA:

 

[mbrooke]

There is a table for determining whether the explosive concentration for any gas is achieved. Fuels explode when the right oxygen-fuel ratio is present and a spark is initiated. There is an LEL (lower explosive limit) and an UEL upper explosive limit). Any gas concentration below or above said limits will "probably not" explode . Here is a sample from NFPA:
View attachment 13405

Does this table stay the same or change with normal variants in ambient temperature?

 

[don_resqcapt19]

There is a table for determining whether the explosive concentration for any gas is achieved. Fuels explode when the right oxygen-fuel ratio is present and a spark is initiated. There is an LEL (lower explosive limit) and an UEL upper explosive limit). Any gas concentration below or above said limits will "probably not" explode . Here is a sample from NFPA:
View attachment 13405

While it is called an explosion, it very likely does not meet the technical definition of an explosion. (that is the propagation speed exceeding the speed of sound) Even black power does not burn fast enough to meet the technical definition of an explosion.

If the concentration is outside the range between LEL and UEL, not only will it not explode, it won't even ignite.

 

[topgone]

Does this table stay the same or change with normal variants in ambient temperature?

The NFPA explicitly says "concentration". Any temperature change from the standard when the tests on those gases were conducted would definitely change the concentration of the mix. As long as those LEL or UEL are not met, no "explosion" can occur. That is why companies always measure gas concentrations on an hourly basis so people working won't come out in pieces!

One caveat though is that gases are never uniformly distributed in a space. It is therefore necessary that gas concentrations are maintained far from the given figures to be safe.