The Arc Fault Detection Device… again.

You have described exactly why it is so difficult to get an arc Mike, unless there is enough hot plasma after the first half cycle the arc is extinguished immediately. This is the situation we see in all the tests on youtube, and why there is this insistence on carbon electrodes or charred cables. In my view, AFDDs do not do that which they are named unless triggered by very artificial conditions. In other words, a solution looking for a non-problem. There is no evidence that they prevent real fires, and even simulated conditions performance does not match loads or installations in the UK. The cost of the devices is unrealistic compared with the fire reduction possible and therefore they should not be a requirement in installations.  I cannot understand how we got to this situation with BS7671, unless there is deliberate deception involved somewhere in the standards chain, or that everyone involved along the chain has been silenced or is incompetent. Changes without evidence and manufacturing tests that need special conditions clearly indicate a serious problem somewhere, so the question is "WHY did no one ever question the devices properly", they certainly have in the UK.

You have described exactly why it is so difficult to get an arc Mike, unless there is enough hot plasma after the first half cycle the arc is extinguished immediately. This is the situation we see in all the tests on youtube, and why there is this insistence on carbon electrodes or charred cables. In my view, AFDDs do not do that which they are named unless triggered by very artificial conditions. In other words, a solution looking for a non-problem. There is no evidence that they prevent real fires, and even simulated conditions performance does not match loads or installations in the UK. The cost of the devices is unrealistic compared with the fire reduction possible and therefore they should not be a requirement in installations.  I cannot understand how we got to this situation with BS7671, unless there is deliberate deception involved somewhere in the standards chain, or that everyone involved along the chain has been silenced or is incompetent. Changes without evidence and manufacturing tests that need special conditions clearly indicate a serious problem somewhere, so the question is "WHY did no one ever question the devices properly", they certainly have in the UK.