parallel arc vs series arc

[hurk27]

Re: parallel arc vs series arc

By Harley you have not witness the CH demos or reviewed U.L. 1699 spec.

I have watched several of these rather embarrassing demo's and when they tried to guillotine a two conductor lamp cord the cord went up in smoke One time the demo showered the room with a barrage of sparks. Another the guillotine 's blade got red hot. When they tried the same experiment with a cord that had a grounding conductor in it it worked just fine. What was funny is with the two conductor lamp cord a regular 15 amp single pole breaker cleared the fault faster with no damage to the cord or guillotine other than the small cut through the insulation. AFCI's will not trip on a parallel arc unless it reach's 75 amp's but a arc that migrates to grounding will trip on as little as 30 ma. This will not protect past the wall receptacle unless a ground fault is involved!

 

[physis]

Re: parallel arc vs series arc

So basicly it might work if a C-H engineer builds your house and even then maybe only if that engineer knows that there will be a public assesment of the products performance. And even then, it might not perform as well as the circuit breaker the NEC doesn't allow you to use.

It's a good thing the NFPA doesn't have any liability in this. I wonder if eventually someone might be able to demonstrate that a three dollar and fifty cent breaker would have prevented a fire while the one a municipality forced them to use did nothing. Or tripped after it got the fire started. Taking out the smoke alarm.

Causing that municipality to be fearful of adopting the NEC.

I don't know what to think. Except take them out of the NEC as a requirement and bring them back for evaluation (it seems like that never happened) when they're ready.

This is as funny as it is ugly.

 

[templdl]

Re: parallel arc vs series arc

We never should forget the fact that we can't rely an either a common fuse of breaker to provide the basic overload of short circuit protection that we expect them to provide. That may be a profound statement but either OCPD must be subjected to a specific current for a given time that will cause the device to operate. Both don't had the sense to see sparks, flames, and smoke that may well be happening which we would want then to respond to. The're just lookin at what's flowing through the wire to them that they respond to and each event will be different.
One can say the say thing for AFCIs. It is obvious that they have been accepted as being able to provide acceptable protection. They may not provide protection for 100% of the things that we expect them to provide but they are a darned sight better than there ever was before.
And, with any type of protection such as common everyday breakers, you should never intentionally overload then, you should never use a GFCI with the expectation that you will be protected when using an electric tool will standing in a flooded basement as well was relying on an AFCI to provide protection from carelessly used cords, wiring devices, etc. Not a good idea.