Arc detection

Discussion in 'Electronic Basics' started by Ryan, Dec 5, 2005.

1. RyanGuest

Redirect appreciated if needed.

How does an arc fault circuit interruptor work? What does it do in
order to detect an arc?

So far, nobody, not even the dealer of our electric supplies has been
able to explain how an arc fault circuit interruptor works. I've not
found the answer on the internet either. The explanations say "unique
circuitry," or "arc detection technology" and other vague words that do
not explain _how_ it works, only what it does.

2. Jasen BettsGuest

I'm going to guess... high frequencies dominating the current
draw.
You may need to search for patents to get the real info.

Bye.
Jasen

3. highpowerGuest

An ARC fault detector in common home circuits utilizes
current-sense-transformer with the 115AC wire and the nuetral wir
both passing through it. If there is any current flowing through th
115V wire which is not also flowing back through the nuetral wire
then this current is obviously going somewhere else back to ground
(from the cheap chinese grinder I bought on ebay, through my body
into the garage floor to earth). The secondary of the transformer i
hundreds of windings which converts the current unbalance to
current output. If this is above a certain threshold, a timer start
and several milliseconds later a relay is opened to stop the power

4. Charles SchulerGuest

You have described a ground-fault detector or interrupter.

5. PCKGuest

and really poorly as well

6. spudnutyGuest

Sorry to top post:
This is from :
http://www.iaei.org/magazine/00_d/gregory.htm
"Arc Recognition
• Flat "shoulders" in the current around current zero
• Arcing current lower than ideal current
• Voltage across the arc approaching a square wave
• Voltage spikes each half cycle as the arc ignites and extinguishes"
Mostly from various things I've read there's a problem with false
trippings. The technology is changing and as the article says
"Any statement about how AFCIs function today may be changed by the
introduction of a new product tomorrow that employs a different
technology."
Richard

• High frequency "noise"