Combo Arc Faults

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domnic said:
so i can have a fault of 600 watts and not trip the device .
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:roll:

That's an interesting way of thinking about it.

To say it another way, if the running load at any instant is less than 600 Watts, the arc fault sensing circuitry in the breaker will not be paying attention.
 
electricalperson said:
the new combo arc faults are designed to detect the series and parallel fault. the branch/feeder arc faults detect just parallel
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IF I DRIVE A STAPLE ON ROMEX AND HIT THE HOT WIRE AND EGC WILL THE DEVICE CLEAR THE FAULT.
 
brantmacga said:
Yeh that circuit is most likely now 'open'.
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MOST LIKELY OPEN YES .BUT IF NOT WILL IT CLEAR .MOST LIKELY A BREAKER OF KIND WILL CLEAR THE FAULT. LAME REPLY
 
domnic said:
MOST LIKELY OPEN YES .BUT IF NOT WILL IT CLEAR .MOST LIKELY A BREAKER OF KIND WILL CLEAR THE FAULT. LAME REPLY
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First please don't use all caps..it is harder to read and is considered to be shouting at us.

A standard breaker may or may not trip on a fault caused by a staple driven too deep. If there is not a solid connection, the current will be limited and will not get into the trip range. With the AFCI if you have 30 mA or more of current the GFP part of the AFCI will trip the breaker.
 
domnic said:
IF I DRIVE A STAPLE ON ROMEX AND HIT THE HOT WIRE AND EGC WILL THE DEVICE CLEAR THE FAULT.
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I'll second Don's opening comment: Internet bulletin board forum etiquette knows ALL CAPS as yelling. . . .

"Will the device clear the fault?" Branch Feeder and Combination Arc-Fault Circuit Interrupters are
  1. magnetic mechanical trip short circuit "breakers"
  2. thermal mechanical trip overcurrent "breakers"
  3. electronic solenoid trip on 30 milliamps current leakage from either the hot or neutral
  4. electronic solenoid trip on a "recognized" series arc waveform(s) more than 5 Amps
  5. electronic solenoid trip on a "recognized" parallel arc waveform(s)
Notice that (1.) & (2.) are what a plain old circuit breaker is.

If an AFCI has all its electronics fried into useless green glass, that "device" still has the levers and springs of a plain old circuit breaker.

The question is, will a plain old circuit breaker clear the fault created by the staple you drove? . . . depends upon the condition of the actual fault. . . . most likely, yes.
 
Al,
Both the series and parallel arc fault trips only look at the waveforms when the current exceeds 5 amps.
 
Thanks, Don,

I remembered Ryan's starting a thread last December questioning the UL 1699 specs for the parallel arc, and the uncertainty of the threshold amperage.

I missed the resumption of the thread in January when Ryan posted the results of his inquiry.

I'm glad to know the correct fact.
 
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