Murray AFCI ground fault ma cutoff?

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semenko

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St. Louis MO
I'm trying to figure out what the actual ground fault sensing limit is for Murray/Siemens combination AFCIs.

The spec sheet (and product pages, etc.) doesn't seem to have the data, though their Intelli-Arc Diagnostic Tool has a ground fault has some LEDs indicating ground fault cutoffs around 50 mA.

Does anyone know if that's specified by Siemens (outside of the high 5A limit set in UL 1699 for AFCIs)?
 

Jraef

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I'm trying to figure out what the actual ground fault sensing limit is for Murray/Siemens combination AFCIs.

The spec sheet (and product pages, etc.) doesn't seem to have the data, though their Intelli-Arc Diagnostic Tool has a ground fault has some LEDs indicating ground fault cutoffs around 50 mA.

Does anyone know if that's specified by Siemens (outside of the high 5A limit set in UL 1699 for AFCIs)?
So why do you want to know? The reason I ask is that many people ASSume that a "Combination AFCI" is a combination of an AFCI and a GFCI. That is NOT true. "Combination" refers to it being a combination of parallel and series arcing faults. There is NO definition of ground fault tripping for this device. It has an LED that says "Ground", but it is NOT a GFCI, nor is it even a GFPE. It is not a "Ground Fault" device in any official sense of the term. All it means is that the tests performed were inclusive of "Grounded" Arc Faults as part of the "Series" testing, meaning 5A, 10A, 15A and then 150% of rated current carbonizing arc fault testing.

So you could, I suppose, think of it as "5,000mA GF protection"...
 
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iwire

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Massachusetts
I believe that is the value for a Class B (equipment protection and limited personal protection) GFCI.

GFCI is always for people protection.

GFP is always for equipment protection.

A class B GFCI, if you can find one is only allowed to be used on pools installed before 1965. :eek:hmy:

Class B is used only with swimming pool underwater lighting fixtures installed prior to local adoption of the 1965 edition of the NEC. A Class B GFCI will trip at a ground fault current greater than 20 mA.

http://www.rockwellautomation.com/rockwellautomation/news/the-journal/exclusive/2013/august3.page
 

Sierrasparky

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USA
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Electrician ,contractor
So why do you want to know? The reason I ask is that many people ASSume that a "Combination AFCI" is a combination of an AFCI and a GFCI. That is NOT true. "Combination" refers to it being a combination of parallel and series arcing faults. There is NO definition of ground fault tripping for this device. It has an LED that says "Ground", but it is NOT a GFCI, nor is it even a GFPE. It is not a "Ground Fault" device in any official sense of the term. All it means is that the tests performed were inclusive of "Grounded" Arc Faults as part of the "Series" testing, meaning 5A, 10A, 15A and then 150% of rated current carbonizing arc fault testing.

So you could, I suppose, think of it as "5,000mA GF protection"...


That is kinda what I wanted to say.
It really has no value as a GFCI.
It is good for knowledge. It is good to know if a brand of AFCI includes this type of detection. Ground fault is one detection of faulty wiring.
 

GoldDigger

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Some do specify Class B GFCI. And although that does not replace required Class A GFCI for a circuit, it probably detects more potential fire producing faults than the whole AFCI section. :)
 

semenko

Member
Location
St. Louis MO
Some do specify Class B GFCI. And although that does not replace required Class A GFCI for a circuit, it probably detects more potential fire producing faults than the whole AFCI section. :)

That's exactly why I'm interested! :) (Plus it'd be useful to know if a fault-to-ground were >5A (!) versus 30ma.)

I understand combination AFCI != GFCI+AFCI (and Murray doesn't yet sell the new AFCI & GFCI breakers), but a number of manufacturers do specify cutoffs (but aren't certified as GFCIs).

e.g. Eaton is very clear about this -- their AFCIs have a 30 ma ground leakage limit: https://www.platt.com/CutSheets/Eaton/CHFCAF.pdf
""" 30mA - Does not meet the requirements of UL 1053 for ground fault sensing & relaying equipment """

I'd guess it's easy for Eaton to reuse their GFCI circuitry in designing the AFCI (maybe anticipating the new GFCI+AFCI requirements), but there's an additional cost to them for UL 1053 certification.
 
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