$2.70/yr saved! Redundant GFCI removal
- Thread starter TradEddie
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At the moment I don't have any AFCIs to measure.
However, I just looked up the circuitry of a typical AFCI; I see that IDT Semiconductors manufactures an integrated circuit specifically for this purpose. Let's look at this (extract from IDT data sheet):
"The ZNRG2061 is a smart system-on-chip for arc-fault detection in photovoltaic solar power systems..." It goes on to say that this chip is used in PV solar power inverters, combiner boxes, DC optimizers, and stand-alone arc-fault circuit interrupters(AFCI). It's UL listed.
That chip measures current through a current transformer and watches for frequencies between 6KHz and 12KHz. Its signal analysis uses a continual 24 bit fast Fourier transform (FFT). This, takes a bit of computing power: the chip has an average supply current of 20milliamps.
Ignoring any other circuitry in the AFCI, this 20ma is about twice the current draw of a GFCI; so I estimate that the AFCI's parasitic power load is at least 2.5 watts, and likely more (perhaps 3 to 5 watts).
However, I just looked up the circuitry of a typical AFCI; I see that IDT Semiconductors manufactures an integrated circuit specifically for this purpose. Let's look at this (extract from IDT data sheet):
"The ZNRG2061 is a smart system-on-chip for arc-fault detection in photovoltaic solar power systems..." It goes on to say that this chip is used in PV solar power inverters, combiner boxes, DC optimizers, and stand-alone arc-fault circuit interrupters(AFCI). It's UL listed.
That chip measures current through a current transformer and watches for frequencies between 6KHz and 12KHz. Its signal analysis uses a continual 24 bit fast Fourier transform (FFT). This, takes a bit of computing power: the chip has an average supply current of 20milliamps.
Ignoring any other circuitry in the AFCI, this 20ma is about twice the current draw of a GFCI; so I estimate that the AFCI's parasitic power load is at least 2.5 watts, and likely more (perhaps 3 to 5 watts).
Sounds like a potential job for minimum mandatory state standards to me! GFCIs are not really a consumer product, and an ENERGY STAR program won't move the market toward more efficient GFCI models unless builders get some kind of credit for including them in new construction/renovation.
BTW, check out the new Home Energy article by some of Cliff's colleagues at LBNL at http://www.homeenergy.org/show/article/id/2252/nav/hotwater.
BTW, check out the new Home Energy article by some of Cliff's colleagues at LBNL at http://www.homeenergy.org/show/article/id/2252/nav/hotwater.
I wonder if gfci breaker use the same amount of power. Instead of adding the gfci outlets needed in our 1950 house I used gfci breakers(which met the code instead of the gfci outlets)
ratsrepus
Minister of Fire
michigan and one other state, eliminated the use of arc fault systems, thank god, what a pain in the ass
Connecticut Yankee
Burning Hunk
What, the clock doesn't count? What about remembering my favorite bagel-heating setting?
