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#144346 - 11/10/05 02:08 AM AFCI: to what sort of IEC device is it comparable?
Wolfgang Offline
Member

Registered: 09/25/05
Posts: 154
Loc: the very West of Germany
I stumbled over a question out of the general discussion forum:

It is asked whether AFCIs are in use outside North America and I must confess, that I have no idea how this device works internally and why I have never heard about its idea so far or any comparable device in EC.

Any idea, is it a successful marketing trick or would it be a progress in safety with us to detect "arcing"? Or is it a North Am specific topic?

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#144347 - 11/10/05 03:54 AM Re: AFCI: to what sort of IEC device is it comparable?
Owain Offline
Member

Registered: 10/26/05
Posts: 19
Loc: Scotland,UK
It is pretty much specific to NAm because the problems they purport to solve are more common in the US. This is because of their use of lower voltage. At 230V, the current produced in a given fault condition is twice as high compared to 115V. We also use different circuit breaker (MCB) types with fast fault current trip as well as overload (thermal) trip, so the circuit breaker trip current could be half as much for the same circuit power rating. This means that a conventional MCB will be far more effective at detecting such a fault on a 230V nominal voltage system.

A far higher proportion of US house fires are electrical in origin compared to the UK. Using half the mains voltage means equivalent power appliances require twice the current, and a poor contact/connection will be giving off 4 times the heat it does on 240V, and thus getting much hotter. The Americans also have widespread use of alumin(i)um wiring. The quality of most US electrical accessories is mediocre compared to the EU, and they still use wirenuts (Scruits) which AIUI were banned in the UK in the sixties, and routinely use unearthed outlets relying on RCD protection instead of, rather than alongside, earthing.

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#144348 - 11/10/05 04:23 AM Re: AFCI: to what sort of IEC device is it comparable?
C-H Offline

Member

Registered: 09/17/02
Posts: 1508
Loc: Stockholm, Sweden
It would be the 100/300 mA RCD.

The AFCI contains and RCD but also an electronic circuit that compares the waveform to known types of faults. It is therefore safer than an ordinary breaker, UL or IEC, if the electronic works. It might take them some time to fine tune the technology, but the manufacturers will sooner or later do it.

Owain is a bit harsh in his comments, but his reasoning is basically right. I wouldn't dare say there are big differences between UL and IEC breakers, but there are differences in the testing standards.

Another factor is what you blame fires on. It seems fires are started by arsonists in Sweden and electrons in America. (Exaggeration!)

[This message has been edited by C-H (edited 11-10-2005).]

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#144349 - 11/10/05 09:29 PM Re: AFCI: to what sort of IEC device is it comparable?
NORCAL Offline
Member

Registered: 09/25/02
Posts: 807
Owain, are you sure about your "facts"???

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#144350 - 11/10/05 09:42 PM Re: AFCI: to what sort of IEC device is it comparable?
frenchelectrican Offline

Member

Registered: 02/06/03
Posts: 938
Loc: Wi/ Paris France { France for ...
The Americans also have widespread use of alumin(i)um wiring


well that partal fact it was common in late 60 to early 70's but really the biggest curpit was inproper use of device and termation set up that what most common source of fire or overheating connection

most home where still have alum branch circuits have to use the devices marked CU/AL otherwise most peoples try to fixed themself and end up a more mess than it worth it.

to splice between alum and coppper wires is very tricky procudure it need specal wirenuts or ireversable crimp one of the two [ the UL have isuse with purple wirenuts]

please do recheck the wiring facts before you post it ok ??

many thanks

Merci , Marc
_________________________
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)


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#144351 - 11/10/05 10:59 PM Re: AFCI: to what sort of IEC device is it comparable?
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Owain,
 Quote:
At 230V, the current produced in a given fault condition is twice as high compared to 115V. We also use different circuit breaker (MCB) types with fast fault current trip as well as overload (thermal) trip

Most MCB's here would under a serious fault, trip on a Magnetic side of the MCB.
 Quote:
A far higher proportion of US house fires are electrical in origin compared to the UK.

And just what brings you to that conclusion?, can you back that up with real figures?.
Reason I say that is because, it depends upon either the OIC's report or that of the Fire Investigator, these people are over-worked and a quick assumption is more or less a certainty.
As I've said in other posts here, I'm all for honest Fire Investigations.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

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#144352 - 11/11/05 04:10 AM Re: AFCI: to what sort of IEC device is it comparable?
Wolfgang Offline
Member

Registered: 09/25/05
Posts: 154
Loc: the very West of Germany
When I'm writing in this NA forum, it is not my intention to tell the North American that km are better than miles. I know to calculate in both ways and there is a long history for their way of doing things.

Back to my original question, i'd just like to ask once more: Does anyone know a device which is constructed similar to an AFCI being on sale anywhere outside North America? As far as I understand the main entreprises that produce this sort of material are at least partly active on both markets like f.i. Schneider or GE. So I wonder why is no market initiative trying to fill this gap?

For Germany I'd say: Never heard
Wolfgang

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#144353 - 11/11/05 09:40 AM Re: AFCI: to what sort of IEC device is it comparable?
Texas_Ranger Offline
Member

Registered: 12/17/01
Posts: 2343
Loc: Vienna, Austria
Not even our teachers at school knew about such a beast, so i strongly doubt such a device has made it to Europe so far. There is also _no_ European information source, lest a German one. Some engineers at news de.sci.ing.elektrotechnik did an online research about a year ago and all they turned up was US sites.
Very interesting thread though! I've been here for several years now and it was not until yesterday that I realized GFCIs and RCDs are in fact not the same!

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#144354 - 11/12/05 06:43 AM Re: AFCI: to what sort of IEC device is it comparable?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
A few old threads on the subject, in which you'll see that there was a lot of debate over just how effective or otherwise AFCIs are:

Arc Fault Breakers

AFCI breakers

Arc-fault circuit-interrupters
And some information from one manufacturer (follow links at bottom of page for more): http://www.zlan.com/arc.htm


As yet, I've not seen anything on this side of the Atlantic which even hints at an AFCI even being under consideration.


 Quote:
At 230V, the current produced in a given fault condition is twice as high compared to 115V.

If the source impedance and resistance of the feeders and branch cables were the same up to the point of the short in both cases, then obviously this is true, but I think there are too many other factors to really make this generalization valid.

Just look at the variations in Zs one can find within the U.K.-- the actual fault current can vary widely on systems all running at the same voltage. The fault current at a rural cottage where the lines run 400 yards down a lane to the nearest pole-top xfmr is quite likely going to be lower at 240V than a similar fault on an American home at 120V with the xfmr right in front of the house.

It would be interesting to collate figures for average source impedance in city/rural areas for both countries.

 Quote:
A far higher proportion of US house fires are electrical in origin compared to the UK.


Do we have some statistics on this? I think we would still need to be very careful about the way such figures are compiled though, and about looking at just proportions.

I have no idea about the actual figures, but if, for example, fires from other non-electrical causes were less common in the U.S., then one would expect the proportion of electrical fires to be higher, which does not imply that electrical fires are more likely, just that they form a larger percentage of total fires.

 Quote:
The quality of most US electrical accessories is mediocre compared to the EU,


I'm not sure how you come to that conclusion. I've seen good and bad on both sides of the pond, and IMHO when we start looking at switchgear (distribution equipment rather than switches & sockets etc.) American construction is undoubtedly far superior to what passes for "quality" products here these days.

 Quote:
and they still use wirenuts (Scruits) which AIUI were banned in the UK in the sixties,


I'm trying to think back to all the photos and violations threads on ECN. We've seen incorrectly installed wirenuts (too many conductors etc.), twisted connections with nothing else to hold them together (as is often found here as well), but I don't recall any in which it was the wirenutted connection per se which was to blame. Backstabbed, push-in connections are another matter though. Ugh!

 Quote:
and routinely use unearthed outlets relying on RCD protection


That's only as a concession for retro fits. All new installs are required to have a ground run to the outlets.

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#144355 - 11/13/05 05:15 AM Re: AFCI: to what sort of IEC device is it comparable?
IanR Offline
Member

Registered: 12/06/04
Posts: 326
Loc: Palm Bay FL USA
I have another explanation for the possibly high ratio of electrical vs nonelectrical fires in the US. I have a good friend who has been the crime scene investigator at my local police dept for many years. He and I were discussing fire reports a while back. He told me that when ever there is a fire, in which the cause is not clearly obvious, it is immediately noted as electrical in origin. I don't know if this is common else where but it seems to be the case in my local.
Just my $.2

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