What is a CAFCI breaker?


Old 07-02-14, 10:03 AM
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What is a CAFCI breaker?

Can any one tell me what a CAFCI breaker is? I know what AFCI is an arc fault breaker. And a GFCI is ground fault which is primarily used in areas that could damp or become damp. Is this some type of combination between the AFCI and GFCI?
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Old 07-02-14, 10:10 AM
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Combination Arc Fault Circuit Interrupter

Here is what I copied from the Siemens webpage:
Combination Type Arc Fault Circuit Interrupters
The Combination Type AFCI differs from the Branch/Feeder AFCI in its ability to detect series arcing faults. The Branch/Feeder AFCI can only detect line-to-neutral and line-to-ground arcing faults. Combination AFCIs provide protection against the high-energy parallel (line-to-neutral and line-to-ground) arcing and low-energy series arcing. “Combination” does NOT mean an AFCI + GFCI. Combination = parallel + series arcing. Combination AFCIs protect downstream branch circuit wiring, cord sets, and power supply cords.
Old 07-02-14, 10:11 AM
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Best description I found, though all I get out of it is that you can use MWBR circuits without tripping.

Maybe one of the Pro's can explain in simple terms.

The main thing is that it is NOT a combination AFCI and GFCI.
Old 07-02-14, 11:10 AM
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The standard AFCI just protects from parallel arcs. Those would be arcs between line and neutral and line and ground.

The CAFCI protects the same as above plus it also protects from opens in a current carrying conductor which would be a series arc.

The diagram below illustrates the differences.

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Old 07-02-14, 03:33 PM
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The AFCI was thef first generation protection and detected one type of arcs. The combination AFCI added the detection for a different type of fault.

They both had a GFI component for Class B 30 mA protection.

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