Newsgroups: sfnet.harrastus.elektroniikka
Subject: Re: KIPIN�SUOJAKYTKIN - miss� viipyy?
Distribution: sfnet
References:   <[email protected]> <[email protected]>  <[email protected]>  <[email protected]> 
Mika Lindblad  writes:

> On 2008-06-11, Matti Kaki  wrote:
> >  Ei tietenk��mn katko. Kuten olen jo _monta_kertaa_ kertonut, se 
> >  kipin�suojakytkin osaa erotella erilaiset kipin�innit, samoin 
> >  kuin h�iri�t toisistaan. Nyt en t�t� en�� kerro. Jos et viimein 
> 
> Esit� meille, miten se toimii. Lohkokaavio, piirikaavio, kipin��
> havainnoivat algoritmit ja muut olennaiset asiat ovat j��neet t�ysin
> pimentoon. Voisit my�s esitt�� mittausdataa, josta k�y ilmi laitteen vaste
> erilaiseen kipin�intiin sek� muuhun h�iri��n. 

Linkkej� aihepiirist�:

http://www.ul.com/regulators/afci/
http://www.cpsc.gov/CPSCPUB/PUBS/afcifac8.PDF
http://www.ul.com/regulators/afci/Dini2.pdf
http://en.wikipedia.org/wiki/Arc-fault_circuit_interrupter
http://www.freepatentsonline.com/7091723.html
http://www.wipo.int/pctdb/en/wo.jsp?wo=2004097872&IA=WO2004097872&DISPLAY=DESC
http://www.arcadvisor.com/afci.html
http://www.mikeholt.com/mojonewsarchive/AFCI-HTML/HTML/AFCI_-_Square_D_Responds~20020815.htm
http://mikeholt.com/mojonewsarchive/AFCI-HTML/HTML/AFCI_-_Why_I_Have_a_Problem_With_It~20020801.htm
http://www.mikeholt.com/htmlnews/nec/pdf/truthaboutafci.pdf
http://www.cpsc.gov/volstd/afci/afcifiretechnology.pdf
http://www.iaei.org/subscriber/magazine/00_d/kimblin.htm
http://www.epanorama.net/links/wire_mains.html#protection


Selvityst� tekniikasta 
http://www.cpsc.gov/volstd/afci/afcifiretechnology.pdf

"Both .good. and .bad. arcs produce a current signature 
or waveform. .Good.
arcs are characterized by being periodic or repetitive (
occur each 60 Hz cycle) and can be
non-sinusoidal (not the shape of a sine wave). .
Bad. arcs are characterized by nonperiodic
or non-repetitive waveforms. 
The AFCI circuitry continuously monitors current
flow through the AFCI. AFCIs use detection circuitry 
to discriminate between normal and
unwanted arcing conditions. Once an unwanted arcing 
condition is detected, the control
circuitry in the AFCI trips the internal contacts, 
thus de-energizing the circuit and reducing
the potential for a fire to occur."

"Methods for the detection of .bad. arcs include looking 
at certain frequencies, d iscontinuities, and 
inconsistencies in the current waveform. For detection, both
magnitude and duration of a particular half cycle are required. 
Some detection algorithms
also look at rising or falling edges of an arcing current 
for their detection criteria. The
industry voluntary standard for AFCIs requires a trip if 
8 half cycles of arcing occur within
a 0.5 second window.
An AFCI should not trip during normal current conditions."

"An AFCI also uses a ground current sensor (typically 30 mA) 
for .pre-arcing. detection and protection. This sensor 
allows the AFCI to detect slowly-developing
insulation breakdown that typically precedes 
line-to-ground and line-to-neutral arc faults.
Additionally, lower level series arcing may become 
a fault to ground in three wire systems
or systems that are grounded. 
The ground current sensor output is amplified and fed into
the logic circuit. If the logic determines that the 
magnitude and duration of the ground
fault is hazardous, the solenoid will open the circuit breaker contacts."

"A test circuit is provided to ensure that the arc fault 
detection circuit is functioning
properly. A test button is used to generate 
a signal that is similar to an arcing output
waveform of the load current sensor."

"The first edition of the Standard for Arc-
Fault Circuit-Interrupters, UL 1699, was published in February 1999."
"The first edition of UL 1699 has three major sections,"

"Figure 3 is a block diagram of a single pole AFCI circuit breaker."
"Figure 4 is a block diagram of a two-pole AFCI circuit breaker."
(katsokaa dokumentista kuvat, en ala t�h�n v��nt�m��n 
mit��n ASCII-imitaatiota noista kaaviosta)

-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/