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Combination AFCI/GFCI Circuit Breakers?
|
|
| Gerald Newton 2007-09-13, 8:25 pm |
| I have just attended the Northwest IAEI Section meeting in Anchorage
Alaska where the 2008 NEC and Analysis of Changes was taught. A new
rule is requiring that all 120-volt, 15- and 20- ampere branch
circuits supplying outlets installed in dwelling unit family rooms,
dining rooms, living rooms, parlors, libraries, bedrooms, sunrooms,
recreation rooms, closets, hallways, or similar rooms or areas shall
be protected by a listed arc-fault circuit interrupter, combination-
type , installed to provide protection for the branch circuit. The
combination-type means that the AFCI provides series and parallel
circuit protection.
Also, the AFCI provides protection from bad arcs that cause fires but
does not provide GFCI protection because the ground fault tip is set
at 50 ma.
Now what came up during break was does anyone make a AFCI/GFCI that
provides both the 5 ma GFCI protection and the AFCI protection and if
they do, why not just go the whole course and require both?
It turns out that Cutler Hammer does make such a device, but Square D
does not.
So now what should we do? Wait for the 2011 NEC or jump the gun and
put these Cutler Hammer AFCI/GFCI devices in now?
| |
| Gerald Newton 2007-09-13, 8:25 pm |
| On Sep 13, 2:44 pm, Gerald Newton <electric...@electrician2.com>
wrote:
> I have just attended the Northwest IAEI Section meeting in Anchorage
> Alaska where the 2008 NEC and Analysis of Changes was taught. A new
> rule is requiring that all 120-volt, 15- and 20- ampere branch
> circuits supplying outlets installed in dwelling unit family rooms,
> dining rooms, living rooms, parlors, libraries, bedrooms, sunrooms,
> recreation rooms, closets, hallways, or similar rooms or areas shall
> be protected by a listed arc-fault circuit interrupter, combination-
> type , installed to provide protection for the branch circuit. The
> combination-type means that the AFCI provides series and parallel
> circuit protection.
>
> Also, the AFCI provides protection from bad arcs that cause fires but
> does not provide GFCI protection because the ground fault tip is set
> at 50 ma.
>
> Now what came up during break was does anyone make a AFCI/GFCI that
> provides both the 5 ma GFCI protection and the AFCI protection and if
> they do, why not just go the whole course and require both?
> It turns out that Cutler Hammer does make such a device, but Square D
> does not.
> So now what should we do? Wait for the 2011 NEC or jump the gun and
> put these Cutler Hammer AFCI/GFCI devices in now?
The FIRE-GUARD=99 Arc Fault Circuit Interrupter (AFCI) is a residential
circuit breaker with an integrated processor which recognizes the
unique current and/or voltage signatures associated with arcing
faults, and acts to interrupt the circuit to reduce the likelihood of
an electrical fire. With the Cutler-Hammer FIRE-GUARD AFCI, protection
from arcing faults is combined with conventional thermal and magnetic
overloads as found in standard residential circuit breakers protecting
wiring from excessive heat or damage due to overloading or short
circuits. FIRE-GUARD AFCI can also be equipped with 5 mA ground fault
protection to protect from personal shock hazards. Now, there is a
residential circuit breaker that provides protection from arcing
faults, conductor damage due to thermal overloads and short circuits,
as well as 5 mA ground fault protection in one integrated design.
from:
http://www.fireguard.info/
| |
| Uncle Monster 2007-09-13, 8:25 pm |
| Gerald Newton wrote:
> I have just attended the Northwest IAEI Section meeting in Anchorage
> Alaska where the 2008 NEC and Analysis of Changes was taught. A new
> rule is requiring that all 120-volt, 15- and 20- ampere branch
> circuits supplying outlets installed in dwelling unit family rooms,
> dining rooms, living rooms, parlors, libraries, bedrooms, sunrooms,
> recreation rooms, closets, hallways, or similar rooms or areas shall
> be protected by a listed arc-fault circuit interrupter, combination-
> type , installed to provide protection for the branch circuit. The
> combination-type means that the AFCI provides series and parallel
> circuit protection.
>
> Also, the AFCI provides protection from bad arcs that cause fires but
> does not provide GFCI protection because the ground fault tip is set
> at 50 ma.
>
> Now what came up during break was does anyone make a AFCI/GFCI that
> provides both the 5 ma GFCI protection and the AFCI protection and if
> they do, why not just go the whole course and require both?
> It turns out that Cutler Hammer does make such a device, but Square D
> does not.
> So now what should we do? Wait for the 2011 NEC or jump the gun and
> put these Cutler Hammer AFCI/GFCI devices in now?
>
When will someone develop the toddler with a paper clip
detector circuit interrupter.
[8~{} Uncle Monster
| |
| Charles Perry 2007-09-13, 8:25 pm |
|
"Gerald Newton" <electrician@electrician2.com> wrote in message
news:1189723450.241886.100340@22g2000hsm.googlegroups.com...
>I have just attended the Northwest IAEI Section meeting in Anchorage
> Alaska where the 2008 NEC and Analysis of Changes was taught. A new
> rule is requiring that all 120-volt, 15- and 20- ampere branch
> circuits supplying outlets installed in dwelling unit family rooms,
> dining rooms, living rooms, parlors, libraries, bedrooms, sunrooms,
> recreation rooms, closets, hallways, or similar rooms or areas shall
> be protected by a listed arc-fault circuit interrupter, combination-
> type , installed to provide protection for the branch circuit. The
> combination-type means that the AFCI provides series and parallel
> circuit protection.
>
> Also, the AFCI provides protection from bad arcs that cause fires but
> does not provide GFCI protection because the ground fault tip is set
> at 50 ma.
>
> Now what came up during break was does anyone make a AFCI/GFCI that
> provides both the 5 ma GFCI protection and the AFCI protection and if
> they do, why not just go the whole course and require both?
> It turns out that Cutler Hammer does make such a device, but Square D
> does not.
> So now what should we do? Wait for the 2011 NEC or jump the gun and
> put these Cutler Hammer AFCI/GFCI devices in now?
>
A coworker (engineer) installed the combo units (5ma trip) in his addition.
One was tripping and we did some investigations to figure out why. Turns
out there was a staple that had nicked the insulation of the neutral
conductor and was shorting it to the grounding conductor. We duplicated
this fault in my lab and tested a regular breaker, a GFCI, an AFCI, and a
combo AFCI/GFCI (5ma). As expected, the regular breaker did not trip.
Neither did the AFCI. The GFCI tripped as expected (half cycle or so). The
combo tripped, but took much longer. I don't have the data in front of me,
but it was something like 5 to 10 cycles. Now, is this a big difference? I
don't know from a human survival standpoint. However, if my wife throws a
toaster in my bathtub, I want the traditional GFCI that trips in half a
cycle, NOT the slower AFCI/GFCI combo unit.
I am still not convinced of the usefulness of the new breakers and question
the required investment verses the limited events that may be detected.
Just my personal opinion.
Charles Perry P.E.
| |
| gfretwell@aol.com 2007-09-13, 8:25 pm |
| On Thu, 13 Sep 2007 18:41:14 -0500, Uncle Monster
<unclemonhatespam@gmail.com> wrote:
>When will someone develop the toddler with a paper clip
>detector circuit interrupter.
It is called the tampre resistand receptacle and that is in the 2008
code too.
| |
| John Gilmer 2007-09-14, 3:25 am |
|
> I am still not convinced of the usefulness of the new breakers and
> question
> the required investment verses the limited events that may be detected.
>
Tee hee!
As the line goes, "Look for the Money."
Conventional CBs in the popular sizes (15/20) are just dirt cheap. They
also last "forever."
But an AFCI or GFCI has a bunch of "accident waiting to happen" electronics
just waiting for a surge or excess humidity. Even if we "assume" the
electronics are good for 30 years there's a significant replacement market
out there.
| |
| Uncle Monster 2007-09-14, 3:25 am |
| gfretwell@aol.com wrote:
> On Thu, 13 Sep 2007 18:41:14 -0500, Uncle Monster
> <unclemonhatespam@gmail.com> wrote:
>
>
> It is called the tampre resistand receptacle and that is in the 2008
> code too.
Oh my God! I'll bet the things will be like the
so called child proof safety caps on pill bottles.
Impossible for older folks to use.
[8~{} Uncle Monster
| |
| Gerald Newton 2007-09-14, 3:25 am |
| On Sep 13, 7:04 pm, Uncle Monster <unclemonhates...@gmail.com> wrote:
> gfretw...@aol.com wrote:
>
>
>
> Oh my God! I'll bet the things will be like the
> so called child proof safety caps on pill bottles.
> Impossible for older folks to use.
>
> [8~{} Uncle Monster
The following information was interpreted using information from the
Lawerence Livermore Labs.
Charles Dalziel invented the GFCI in 1961. It is my understanding
that he worked at these labs or nearby.
Experience has shown 5 mA can cause uncomfortable shock, and in cases
of children or where persons are on an operating table, a current of 5
mA may cause serious discomfort and complications. By Figure 1 the UL
Standard 943 performance curve requires the GFCI to open the circuit
in 7 seconds at 4 mA, in 5 seconds at 5 mA, and in 0.04 seconds at 110
mA fault current. . However, the performance curve for the LM 1851 IC
has .4 seconds at 4 mA, .2 seconds at 5 mA, and .02 seconds at 110 mA.
Ventricular fibrillation that alters the heart's normal rhythmic
pumping action can be initiated by a current flow of 75 mA or greater
for 5 seconds (5-s) or more through the chest cavity.
To calculate the probability of ventricular fibrillation perform the
following: To determine the 5-s current flow (in mA) necessary to
cause a 0.5% probability of ventricular-fibrillation, multiply a
person's weight (in lb) by 0.49. To determine the 5-s current flow (in
mA) necessary to cause a 99.5% probability of ventricular
fibrillation, multiply a person's weight (in lb) by 1.47. (Reference:
Lawrence Livermore National Laboratory, university of California.)
The 99.5% probability for a 6 pound infant is 1.47 x 6 equals 8.82 mA
for 5 seconds. This is within the safe limits of the operational curve
of a GFCI by a slim margin. However, the .5% probability is 0.49 x 6 =
2.94 mA. for 5 seconds. The UL and National Semiconductor operational
curves do not require a GFCI to operate for less than 4 mA of fault
current. Based on these formulae, operational curves, and calculations
the operation of a GFCI can incur a possible 0.5% probability of
electrocution by ventricular fibrillation for infants that weigh less
than 8.2 pounds (4mA / .49). It should be remembered that for
circuits protected by a GFCI circuit breaker there will be leakage
current and this leakage current increases as the circuit length
increases. If the leakage current is above 2.06 mA then the fault
current required to trip the GFCI circuit breaker would only be 2.94
mA for an average GFCI. These conclusions are only possibilities.
The trip time verses fault current curves allow for many other
conclusions.
Poster's note: This calculation is not verifiable since we cannot
experimnet with infants. It is very possible that the calculation is
too liberal and in fact, 4 ma may cause ventricular fibrillation in
infants.
Ref:
http://www.llnl.gov/es_and_h/hsm/doc_16.01/doc16-01.pdf
The 2008 NEC rule to require tamper proof receptacles protects
children, but we need GFCI's to protect adults.
Can old people use these tamper proof receptacles? Good question. I
guess we will find out.
| |
| ChairmanOfTheBored 2007-09-14, 3:25 am |
| On Thu, 13 Sep 2007 22:04:36 -0500, Uncle Monster
<unclemonhatespam@gmail.com> wrote:
>gfretwell@aol.com wrote:
>
>Oh my God! I'll bet the things will be like the
>so called child proof safety caps on pill bottles.
>Impossible for older folks to use.
>
>[8~{} Uncle Monster
That makes you afeared dunnit? :-]
| |
| ChairmanOfTheBored 2007-09-14, 3:25 am |
| On Thu, 13 Sep 2007 21:10:14 -0700, Gerald Newton
<electrician@electrician2.com> wrote:
We didn't need a primer, idiot.
| |
| Uncle Monster 2007-09-14, 3:25 am |
| ChairmanOfTheBored wrote:
> On Thu, 13 Sep 2007 22:04:36 -0500, Uncle Monster
> <unclemonhatespam@gmail.com> wrote:
>
>
>
> That makes you afeared dunnit? :-]
Some of my older friends have problems understanding those
newfangled GFCI outlets. I've had to show them how to reset
the darn things and explain how they work. It's very hard
for many old folks to see or push that little reset button.
If the design of electrical outlets changes, I'm afraid many
people, not just old people, blond women perhaps, will have
a lot of trouble with the new devices.
[8~{} Uncle Monster
| |
| Gerald Newton 2007-09-14, 1:25 pm |
| On Sep 13, 11:54 pm, Uncle Monster <unclemonhates...@gmail.com> wrote:
> ChairmanOfTheBored wrote:
>
>
>
>
>
> Some of my older friends have problems understanding those
> newfangled GFCI outlets. I've had to show them how to reset
> the darn things and explain how they work. It's very hard
> for many old folks to see or push that little reset button.
> If the design of electrical outlets changes, I'm afraid many
> people, not just old people, blond women perhaps, will have
> a lot of trouble with the new devices.
>
> [8~{} Uncle Monster- Hide quoted text -
>
> - Show quoted text -
I think the AFCI combined with the GFCI combined with the tamper proof
receptacles is going to bring high tech to old people's receptacles
and maybe become like operating a DVD player.
| |
| gfretwell@aol.com 2007-09-14, 1:25 pm |
| On Thu, 13 Sep 2007 22:49:40 -0400, "John Gilmer" <nni/gilmer@nni.com>
wrote:
>But an AFCI or GFCI has a bunch of "accident waiting to happen" electronics
>just waiting for a surge or excess humidity. Even if we "assume" the
>electronics are good for 30 years there's a significant replacement market
>out there.
The real problem with rushing all of this into the code is this is an
evolving technology that still can't detect a series arc (the one from
a loose plug, cracked wire and all of those "aluminium" problems).
They already have millions of obsolete AFCIs out there mandated in the
1999 code and enforced in the 2002 code that can't detect the bad
power cord they scared us with when these were first proposed. The
original AFCI only detects shorts in the wall. Finding a short in a
power cord is what the "combination" unit is supposed to do.
None can find a loose connection or partially broken wire.
Then you have a bunch of Square D units that don't work at all and
have been recalled but there is no tracking on this recall so most
still remain in the customer's home.
The technology is so proprietary that the industry can't agree on what
a tester should inject in the line to see if the product works. An
arcing short that trips a Square D might not be seen by a Cutler
Hammer and vice versa.
It is clear this is a product that is not ready for the public yet but
has been jammed down our throat by NFPA and Cutler Hammer, the
inventor and who proposed in in 1997. It is being tested in our homes,
by force of law and the customer is paying for it.
| |
| gfretwell@aol.com 2007-09-14, 1:25 pm |
| On Fri, 14 Sep 2007 07:43:53 -0700, Gerald Newton
<electrician@electrician2.com> wrote:
>I think the AFCI combined with the GFCI combined with the tamper proof
>receptacles is going to bring high tech to old people's receptacles
>and maybe become like operating a DVD player.
The problem is there are already "insertion force" problems with the
ridiculously expensive tamper proof receptacles out there now. Imagine
how bad they will be when we get down to the ones builders use to hit
a price point.
| |
| Gerald Newton 2007-09-14, 1:25 pm |
| On Sep 14, 6:59 am, gfretw...@aol.com wrote:
> On Thu, 13 Sep 2007 22:49:40 -0400, "John Gilmer" <nni/gil...@nni.com>
> wrote:
>
>
> The real problem with rushing all of this into the code is this is an
> evolving technology that still can't detect a series arc (the one from
> a loose plug, cracked wire and all of those "aluminium" problems).
> They already have millions of obsolete AFCIs out there mandated in the
> 1999 code and enforced in the 2002 code that can't detect the bad
> power cord they scared us with when these were first proposed. The
> original AFCI only detects shorts in the wall. Finding a short in a
> power cord is what the "combination" unit is supposed to do.
> None can find a loose connection or partially broken wire.
> Then you have a bunch of Square D units that don't work at all and
> have been recalled but there is no tracking on this recall so most
> still remain in the customer's home.
> The technology is so proprietary that the industry can't agree on what
> a tester should inject in the line to see if the product works. An
> arcing short that trips a Square D might not be seen by a Cutler
> Hammer and vice versa.
> It is clear this is a product that is not ready for the public yet but
> has been jammed down our throat by NFPA and Cutler Hammer, the
> inventor and who proposed in in 1997. It is being tested in our homes,
> by force of law and the customer is paying for it.
If what you say is true, I think we may have a problem adopting the
2008 NEC. The AFCI requirement is not going to be accepted without
further investigation.
We need additional information.
| |
|
| Charles Perry wrote:
> "Gerald Newton" <electrician@electrician2.com> wrote in message
> news:1189723450.241886.100340@22g2000hsm.googlegroups.com...
I think they are mostly 30 ma.
[color=darkred]
>
> A coworker (engineer) installed the combo units (5ma trip) in his addition.
> One was tripping and we did some investigations to figure out why. Turns
> out there was a staple that had nicked the insulation of the neutral
> conductor and was shorting it to the grounding conductor. We duplicated
> this fault in my lab and tested a regular breaker, a GFCI, an AFCI, and a
> combo AFCI/GFCI (5ma). As expected, the regular breaker did not trip.
> Neither did the AFCI. The GFCI tripped as expected (half cycle or so). The
> combo tripped, but took much longer. I don't have the data in front of me,
> but it was something like 5 to 10 cycles. Now, is this a big difference? I
> don't know from a human survival standpoint. However, if my wife throws a
> toaster in my bathtub, I want the traditional GFCI that trips in half a
> cycle, NOT the slower AFCI/GFCI combo unit.
Interesting. Why would the AFCI/GFCI was slower. A new topic of
investigation for EPRI.
As you probably know, a GFCI includes a function that detects downstream
N-G shorts with no load. When an AFCI has a load there will be a voltage
drop that can produce the N-G fault current to trip the AFCI.
[Are you suggesting the code should add 'wife malice' protection? An
exciting new field.]
>
> I am still not convinced of the usefulness of the new breakers and question
> the required investment verses the limited events that may be detected.
>
> Just my personal opinion.
IMHO it would have been appropriate for the extension of AFCIs beyond
the previous bedrooms to be based on the record of the AFCIs already
installed in bedrooms. It wasn't.
--
bud--
| |
|
| gfretwell@aol.com wrote:
>
> The real problem with rushing all of this into the code is this is an
> evolving technology that still can't detect a series arc (the one from
> a loose plug, cracked wire and all of those "aluminium" problems).
> They already have millions of obsolete AFCIs out there mandated in the
> 1999 code and enforced in the 2002 code that can't detect the bad
> power cord they scared us with when these were first proposed. The
> original AFCI only detects shorts in the wall. Finding a short in a
> power cord is what the "combination" unit is supposed to do.
The existing AFCIs that detect parallel arcs should detect arcs in power
cords from wire-to-wire. H-N arcs are supposed to produce enough current
to trip the AFCI. And if there is a ground wire, I think the logic was
that the arc would rapidly involve a ground fault so ground fault
detection was included.
> None can find a loose connection or partially broken wire.
> It is clear this is a product that is not ready for the public yet but
> has been jammed down our throat by NFPA and Cutler Hammer, the
> inventor and who proposed in in 1997. It is being tested in our homes,
> by force of law and the customer is paying for it.
Are there any commercial "combination" (series/parallel) AFCIs on the
market yet?
I agree it was stupid for the 2008 NEC to vastly expand the use of
"combination" AFCIs, required only in bedrooms in 2008 by the 2002 NEC,
when the devices didn't exist and did not have field-use experience.
Will be interesting what AHJs do with AFCIs in adopting the 2008 NEC.
--
bud--
| |
| Charles Perry 2007-09-14, 1:25 pm |
|
"bud--" <remove.BudNews@isp.com> wrote in message
news:694b6$46eaaf46$4213ebca$18988@DIALUPUSA.NET...
> Charles Perry wrote:
>
> I think they are mostly 30 ma.
>
>
> Interesting. Why would the AFCI/GFCI was slower. A new topic of
> investigation for EPRI.
Keep in mind that we tested using a single make/model of each type. We did
test multiple units of the same make/model of the combo unit just to make
sure we were seeing what we thought we were seeing. We also done some
testing of tripping of AFCI breakers due to EMI/EMC problems. Just think,
your neighbor installs a new heat pump with an adjustable speed drive and
your breakers starts tripping. Could happen. I know they say the filtering
is great, etc but we make a living cleaning up after things that don't
exactly work as predicted.
Now if I could just get several utilities to fund some AFCI testing work ;-)
>
> As you probably know, a GFCI includes a function that detects downstream
> N-G shorts with no load. When an AFCI has a load there will be a voltage
> drop that can produce the N-G fault current to trip the AFCI.
>
> [Are you suggesting the code should add 'wife malice' protection? An
> exciting new field.]
>
Hahaha. I have to be careful what I say right now. I am recovering from
ACL reconstruction (replacement actually) surgery that happend one week ago
today. I am VERY dependant on my wonderful spouse (she might be reading
over my shoulder) during this recovery!
>
> IMHO it would have been appropriate for the extension of AFCIs beyond the
> previous bedrooms to be based on the record of the AFCIs already installed
> in bedrooms. It wasn't.
Agreed. It was based on undue influence by those with GREED. IMO of course.
Charles
| |
| gfretwell@aol.com 2007-09-14, 8:25 pm |
| On Fri, 14 Sep 2007 11:22:50 -0500, bud-- <remove.BudNews@isp.com>
wrote:
>Are there any commercial "combination" (series/parallel) AFCIs on the
>market yet?
"Combination" refers to btranch circuit wiring plus line cord
protection. The first swing at this required so much fault current
(60-70a) that you could not reliably get that much in a lamp cord.
| |
| Gerald Newton 2007-09-15, 3:25 am |
| On Sep 14, 3:17 pm, gfretw...@aol.com wrote:
> On Fri, 14 Sep 2007 11:22:50 -0500, bud-- <remove.BudN...@isp.com>
> wrote:
>
>
> "Combination" refers to btranch circuit wiring plus line cord
> protection. The first swing at this required so much fault current
> (60-70a) that you could not reliably get that much in a lamp cord.
I did hear several panel members discuss the ground fault trip rating
for AFCI's. They said that the first AFCI's were made to trip at 5 ma
ground fault current, but his "competed with" the GFCI's so they run
the ground fault trip up to 50 ma. Now what they meant is a mystery.
Did they mean the market was competing or did they mean the AFCI
wasn't working right when a GFCI receptacle was installed on the AFCI
circuit?
| |
| gfretwell@aol.com 2007-09-15, 3:25 am |
| On Fri, 14 Sep 2007 21:39:09 -0700, Gerald Newton
<electrician@electrician2.com> wrote:
>On Sep 14, 3:17 pm, gfretw...@aol.com wrote:
>
>I did hear several panel members discuss the ground fault trip rating
>for AFCI's. They said that the first AFCI's were made to trip at 5 ma
>ground fault current, but his "competed with" the GFCI's so they run
>the ground fault trip up to 50 ma. Now what they meant is a mystery.
>Did they mean the market was competing or did they mean the AFCI
>wasn't working right when a GFCI receptacle was installed on the AFCI
>circuit?
I am guessing they were just trying to avoid some nuisance tripping by
making the GF protection higher. I do belive most of the real
protection is coming from the GFP protection, not the snake oil in arc
detection. Ground fault protection is a very simple technology and it
responds to the first fault, not having to sort out locked rotors and
inrush.
| |
|
| gfretwell@aol.com wrote:
> On Fri, 14 Sep 2007 11:22:50 -0500, bud-- <remove.BudNews@isp.com>
> wrote:
>
>
>
> "Combination" refers to branch circuit wiring plus line cord
> protection. The first swing at this required so much fault current
> (60-70a) that you could not reliably get that much in a lamp cord.
I dug out some notes and reread a couple sources. The sources are:
http://www.cpsc.gov/volstd/afci/AFCIFireTechnology.pdf
http://www.iaei.org/subscriber/maga..._gregmanche.htm
UL did a survey of 1590 residential receptacles. 75A short circuit
current was available at the end of 6 foot of #18 cord plugged into all
(or almost all) the receptacles. A parallel arc, wire-to–wire, uses the
available fault current but may not peak to quite 75A. AFCIs out there
now should detect most parallel arcs in cord sets.
Series arcs should be able to be detected at a 5A arc level. (Sounds
like a major challenge.)
Branch/Feeder AFCI
Required for bedrooms in the 2002 NEC.
Install as a circuit breaker (or at the panel) and detects arcs on
branch circuits and feeders. They also detect arcs on cord sets plugged
into a receptacle. The arc detection is at the 75A level so it detects
parallel arcs.
But there is also a test for "carbonized path" “series” arc on Romex.
Since Romex has a ground wire, I believe this is found by the ground
fault detection, which IIRC is required to be 50mA but is commonly 30
mA. If the arc was H-N, it would fairly rapidly also become a ground
fault. (UL did limited tests of "glowing connection" series arcs on
grounding type receptacles, and about half eventually tripped an AFCI
from the ground fault current that developed.)
Outlet circuit AFCI
Installs as a receptacle and may have wire through (like a GFCI receptacle).
Arc detection is at the 5A level, so they will detect series and
parallel arcs. Can detect upstream series arcs.
Combination AFCI
The 2005 NEC requires all AFCIs installed after 1-1-08 to be Combination
type.
Installs as a circuit breaker and combines the protection of
Branch/Feeder and Outlet Circuit.
Will detect series arcs.
--
bud--
| |
|
| GFCI's All Over the House ???
How much do the market rends affect the NEC Regulations & how many
people actually got shocked in their living room.
I don't care & will install whatever is best & available ....In an
educated society there is nothing wrong with the present CB's, but any
improvement will only bring more smiles & cashflow;)
Roy Q.T.
Urban Technician
[I don't make em, I just fix em]
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| Charles Perry 2007-09-15, 9:25 am |
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"Roy" <ROYKEY@webtv.net> wrote in message
news:25161-46EB9CA4-236@storefull-3255.bay.webtv.net...
> GFCI's All Over the House ???
> How much do the market rends affect the NEC Regulations & how many
> people actually got shocked in their living room.
>
> I don't care & will install whatever is best & available ....In an
> educated society there is nothing wrong with the present CB's, but any
> improvement will only bring more smiles & cashflow;)
>
> Roy Q.T.
> Urban Technician
> [I don't make em, I just fix em]
>
Did you ever figure out that a GFCI receptacle will provide protection on a
two wire circuit? Or do you still refuse to believe this?
Charles Perry P.E.
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| ChairmanOfTheBored 2007-09-15, 1:25 pm |
| On Sat, 15 Sep 2007 09:16:12 -0400, "Charles Perry"
<pipesandtobacco@hotmail.com> wrote:
>
>"Roy" <ROYKEY@webtv.net> wrote in message
>news:25161-46EB9CA4-236@storefull-3255.bay.webtv.net...
>
>Did you ever figure out that a GFCI receptacle will provide protection on a
>two wire circuit? Or do you still refuse to believe this?
>
>Charles Perry P.E.
>
He and the term "figure" do not go together.
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| From: RUBored@crackasmile.org (ChairmanOfTheBored)
On Sat, 15 Sep 2007 09:16:12 -0400,
"Charles Perry" <pipesandtobacco@hotmail.com> wrote:
"Roy" <ROYKEY@webtv.net> wrote in
GFCI's All Over the House ???
How much do the market rends affect the NEC Regulations & how many
people actually got shocked in their living room.
I don't care & will install whatever is best & available ....In an
educated society there is nothing wrong with the present CB's, but any
improvement will only bring more smiles & cashflow;)
Roy Q.T.
Urban Technician
[I don't make em, I just fix em]
Did you ever figure out that a GFCI receptacle will provide protection
on a two wire circuit? Or do you still refuse to believe this?
Charles Perry P.E.
=A0=A0=A0=A0He and the term "figure" do not go together.
Yeah I knew that., I never ignore a metallic box but forget to pull
through a ground conductor nah...I won't even mention what the green
screw on Every GFCI is for - Do you know that you can drive a 4 wheel
car on 2 wheels...If you're a Stunt Man  Go Figure.....
Roy Q.T.
Urban Technician
[I don't make em, I just fix em]
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| Gerald Newton 2007-09-15, 5:25 pm |
| On Sep 14, 11:39 pm, bud-- <remove.BudN...@isp.com> wrote:
> gfretw...@aol.com wrote:
>
>
>
> I dug out some notes and reread a couple sources. The sources are:http://www.cpsc.gov/volstd/afci/AFC..._gregmanche.htm
>
> UL did a survey of 1590 residential receptacles. 75A short circuit
> current was available at the end of 6 foot of #18 cord plugged into all
> (or almost all) the receptacles. A parallel arc, wire-to-wire, uses the
> available fault current but may not peak to quite 75A. AFCIs out there
> now should detect most parallel arcs in cord sets.
>
> Series arcs should be able to be detected at a 5A arc level. (Sounds
> like a major challenge.)
>
> Branch/Feeder AFCI
> Required for bedrooms in the 2002 NEC.
> Install as a circuit breaker (or at the panel) and detects arcs on
> branch circuits and feeders. They also detect arcs on cord sets plugged
> into a receptacle. The arc detection is at the 75A level so it detects
> parallel arcs.
> But there is also a test for "carbonized path" "series" arc on Romex.
> Since Romex has a ground wire, I believe this is found by the ground
> fault detection, which IIRC is required to be 50mA but is commonly 30
> mA. If the arc was H-N, it would fairly rapidly also become a ground
> fault. (UL did limited tests of "glowing connection" series arcs on
> grounding type receptacles, and about half eventually tripped an AFCI
> from the ground fault current that developed.)
>
> Outlet circuit AFCI
> Installs as a receptacle and may have wire through (like a GFCI receptacle).
> Arc detection is at the 5A level, so they will detect series and
> parallel arcs. Can detect upstream series arcs.
>
> Combination AFCI
> The 2005 NEC requires all AFCIs installed after 1-1-08 to be Combination
> type.
> Installs as a circuit breaker and combines the protection of
> Branch/Feeder and Outlet Circuit.
> Will detect series arcs.
>
> --
> bud--
Thank you for the excellent references. (I guess I am going to renew
my IAEI membership again.) The IAEI article was excellent.
There are a lot of rumours and misinformation about AFCI's and it is
going to take some convincing arguments to convince people the 2008
NEC is correct.
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| Gerald Newton 2007-09-15, 5:25 pm |
| On Sep 15, 5:16 am, "Charles Perry" <pipesandtoba...@hotmail.com>
wrote:
> "Roy" <ROY...@webtv.net> wrote in message
>
> news:25161-46EB9CA4-236@storefull-3255.bay.webtv.net...
>
>
>
>
> Did you ever figure out that a GFCI receptacle will provide protection on a
> two wire circuit? Or do you still refuse to believe this?
>
> Charles Perry P.E.
I installed GFCI's circuit breakers and almost all my home circuits.
Just two weeks ago I was practically wrapped around the well pressure
tank when I touched a 120 volt hot terminal by accident and the GFCI
tripped.
Now on the two wire GFCI. I do not know if they work but when my Mom
sold her house that was wired in two wire romex many years ago, we had
to replace all the receptacles with GFCI receptacles before it could
be sold. The bank financing the buyer required an inspection by a PE
who said it had to be done. It took about three days of labor and
cost about $300 in materials.
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| daestrom 2007-09-15, 5:25 pm |
|
"Gerald Newton" <electrician@electrician2.com> wrote in message
news:1189883694.041484.30920@57g2000hsv.googlegroups.com...
> On Sep 15, 5:16 am, "Charles Perry" <pipesandtoba...@hotmail.com>
> wrote:
>
> I installed GFCI's circuit breakers and almost all my home circuits.
> Just two weeks ago I was practically wrapped around the well pressure
> tank when I touched a 120 volt hot terminal by accident and the GFCI
> tripped.
> Now on the two wire GFCI. I do not know if they work but when my Mom
> sold her house that was wired in two wire romex many years ago, we had
> to replace all the receptacles with GFCI receptacles before it could
> be sold. The bank financing the buyer required an inspection by a PE
> who said it had to be done. It took about three days of labor and
> cost about $300 in materials.
>
ISTR that a two-wire circuit with GFCI is an acceptable alternative to not
having a grounding conductor. (part of the current code also says you have
to mark any three-prong outlets that don't have a grounding conductor and
are protected by such a GFCI with some special label).
As far as selling an existing home, you seem to have the 'exception that
proves the rule'. Most jurisdictions just require that the home comply with
the code that was in effect when the home was built (i.e. it was 'built to
code'). But most locales don't require that the home comply with all the
*current* codes. Most AHJ don't require *backfitting* a building. That
some PE would say it had to be backfit to comply with current code seems
pretty bizare.
We have houses in NY that are >100 years old and much of the wiring would be
considered 'sub-standard' by todays code. Yet the homes are bought and sold
all the time.
Now, any remodeling or new construction.... that's a different matter.
daestrom
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| Charles Perry 2007-09-15, 5:25 pm |
|
"Roy" <ROYKEY@webtv.net> wrote in message
news:12167-46EC2A78-24@storefull-3258.bay.webtv.net...
From: RUBored@crackasmile.org (ChairmanOfTheBored)
On Sat, 15 Sep 2007 09:16:12 -0400,
"Charles Perry" <pipesandtobacco@hotmail.com> wrote:
<snip>
[color=darkred]
>Yeah I knew that., I never ignore a metallic box but forget to pull
>through a ground conductor nah...I won't even mention what the green
>screw on Every GFCI is for - Do you know that you can drive a 4 wheel
>car on 2 wheels...If you're a Stunt Man Go Figure.....
>Roy Q.T.
>Urban Technician
>[I don't make em, I just fix em]
You knew that? Odd, if you look at your posts to this very newsgroup in
2005 you will find a VERY long and tiring thread where many experts tried to
explain this to you but you refused to believe it. In "Roy World" things
work different than in real world.
Charles Perry P.E.
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| Oh' Stop It Chas Perry P.E. I just said even though they work they are
not making use of all the screws on it. Just like you guys I have more
screws to attach stuff too than you give me credit for
Roy Q.T.
Urban Technician
[I don't make em, I just fix em]
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| ChairmanOfTheBored 2007-09-15, 8:25 pm |
| On Sat, 15 Sep 2007 16:42:08 -0400, ROYKEY@webtv.net (Roy) wrote:
>Oh' Stop It Chas Perry P.E. I just said even though they work they are
>not making use of all the screws on it.
Bwuahahahahahaa!
As is the case with your brain.
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| Charles Perry 2007-09-15, 8:25 pm |
|
"Roy" <ROYKEY@webtv.net> wrote in message
news:27526-46EC43A0-220@storefull-3251.bay.webtv.net...
> Oh' Stop It Chas Perry P.E. I just said even though they work they are
> not making use of all the screws on it. Just like you guys I have more
> screws to attach stuff too than you give me credit for
>
> Roy Q.T.
> Urban Technician
> [I don't make em, I just fix em]
>
Actually you stated that a GFCI would not, could not, work with only two
wires. You did not understand how a GFCI works, and I would not be
surprised if you still don't understand it.
As for loose screws, most of your tech. related posts have proven that you
have an abundance of knowledge in that area.
Charles Perry P.E.
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| John Gilmer 2007-09-15, 8:25 pm |
|
> I am guessing they were just trying to avoid some nuisance tripping by
> making the GF protection higher. I do belive most of the real
> protection is coming from the GFP protection, not the snake oil in arc
> detection. Ground fault protection is a very simple technology and it
> responds to the first fault, not having to sort out locked rotors and
> inrush.
Ground fault protection at "moderate" (as compared to 15/20/30 amp currents
could likely be accomplished with 100% electro-mechanical stuff (just like
the CBs) if you don't load on the requirement to detect G-N "shorts."
If the folks writing the NEC really want to install "smart" CB boxes perhaps
a "ground up" solution can be devised.
I believe that about 20 years ago some folks were talking about "smart"
wiring whereby an appliance would not receive any juice until the "smart
wiring" determines that it's "safe" to so do. Does anyone know what
happened to that?
Back to the AFCIs: the more I hear about these things the more convinced I
am that there is a "hidden agenda." Not of the actual "fact" make sense.
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| Gerald Newton wrote:
>
> Thank you for the excellent references. (I guess I am going to renew
> my IAEI membership again.) The IAEI article was excellent.
I don't remember if it was obvious, but the IAEI article has 3 parts.
http://www.iaei.org/subscriber/maga..._gregmanche.htm
Part 2 is on AFCI installation and troubleshooting
http://www.iaei.org/subscriber/maga...03d_gregory.htm
Part 3 is less interesting; information includes discussion on AFCIs in
the 2005 NEC
> There are a lot of rumours and misinformation about AFCI's and it is
> going to take some convincing arguments to convince people the 2008
> NEC is correct.
There are 3 posters in this thread (including me) that think the 2008
NEC is wrong.
--
bud--
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