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11-20-2010, 03:38 PM #1
Number of downline outlets on GFCI
Is there a specific number of outlets allowed downline from a ground fault protected outlet?
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11-20-2010, 04:10 PM #2
Re: Number of downline outlets on GFCI
edited
Last edited by matt faust; 11-20-2010 at 04:34 PM.
Matt Faust
Real Estate Inspector
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11-20-2010, 04:23 PM #3
Re: Number of downline outlets on GFCI
The gfci protects the entire circuit and does not influence
the number of plugs down stream.
One thing to be very careful of where gfci's are concerned is
is the potential of line and load reversal.
This would be when the energized hot wire is not on the incoming
"line " terminal.
To test for line and load reversal insert your 3 light tester - press the test button,
if the reset button pops out, indicating normal operation, but there is still power
to your tester, the most likely cause is line and load reversal.
(from EIED/Hansen/Kardon/Casey)
mf
Last edited by matt faust; 11-20-2010 at 04:35 PM.
Matt Faust
Real Estate Inspector
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11-20-2010, 04:55 PM #4
Re: Number of downline outlets on GFCI
hey ron
not a sparky and one will soon tune in
but i think it is a volts x amps thing, but i think 10 outlets on a 15 amp breaker and up to 15 on a 20 amp
take it away sparky
chas
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11-20-2010, 08:15 PM #5
Re: Number of downline outlets on GFCI
Depends Residential or other occupancy, number of conductors for the circuit (GEC or not), which edition of the NEc has been adopted, and what if any local amendments, and the manufacturer's instructions and limitations (and perhaps a few other factoids, depending).
For example older editions of the NEC did not allow for line side protection from a in old ungrounded (no egc) wiring. Non-residential occupancies (unammended NEC) limits the number of receptacles per circuit at 90 va per, etc. Fixed in-place appliances - even if cord-and-plug connected are limited draw upon circuits, etc. Specific use or dedicated, or individual use circuits may have limitations (bathroom receptacle circuits, etc.).
So, it depends. Perhaps if you narrowed down the question a bit?
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11-20-2010, 08:28 PM #6
Re: Number of downline outlets on GFCI
HG
no offense but what did you say--
cvf
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11-20-2010, 08:35 PM #7
Re: Number of downline outlets on GFCI
Oops, meant "EGC or not" transposed when typing (not GEC).
Charlie,
What didn't you understand?
Regarding your earlier post:
but i think it is a volts x amps thing, but i think 10 outlets on a 15 amp breaker and up to 15 on a 20 amp
Unless local ammendment, IN GENERAL, there are no restrictions as to the number of occasional use receptacles on residential occupancies 15A or 20A circuit.
Other than residential occupancies, the rule is 90 VA (volt-amps, that is volts times amps) calculated per receptacle (thats 180 VA per duplex receptacle) calculated for the 15A (to 80% or 1440 VA or up to 8 duplex, or 7 following, excluding any other loads) or 20A (to 80% or 1920 VA or up to 10 duplex, or up to 9 following, excluding any other loads) per circuit.
That "rule" you were vaguely referring to has nothing to do with GFCI protection, load-side of a combination device or breaker, it has to do with other-than-residential occupancies, unless you have a local ammendment that says otherwise.
However, restrictions do apply for fixed in place, cord-and-plug connected appliances sharing a branch circuit with other (even occasional use) loads, depending on the "load" of the fixed-in-place appliance, etc.
Regarding older editions of the NEC, when installed a GFCI combination receptacle to replace an ungrounded one (receptacle) in an ungrounded circuit (no EGC, such as knob-and-tube wiring) used to be that you were not allowed to wire load side protection (had to pig-tail and not feed through, i.e. only protect face), more recent editions allowed to protect through load side, mark combination device "no equipment ground" and install grounding type receptacles line side, marking those line side "gfci protected" AND "no equipment ground".
Other situations (one of the "etc.") includes Multi-wire-branch-circuits.
Refered to other conditions which may restrict both the number of receptacles, location, etc. Also referred to mfg instructions and limitations.
Back to the OP's question:
Is there a specific number of outlets allowed downline from a ground fault protected outlet?
What didn't "compute"?
Last edited by H.G. Watson, Sr.; 11-20-2010 at 09:12 PM.
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11-20-2010, 09:49 PM #8
Re: Number of downline outlets on GFCI
edited
Last edited by matt faust; 11-21-2010 at 08:54 PM.
Matt Faust
Real Estate Inspector
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11-20-2010, 10:05 PM #9
Re: Number of downline outlets on GFCI
hg
i understood what ron was asking--it's simple. your answers are not.
cvf
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11-20-2010, 10:32 PM #10
Re: Number of downline outlets on GFCI
Really? And just what was that? And what the heck was your first response based upon? Where did you pull THAT from (and based upon WHAT)?
The answer to Ron's question is.... could be zero to infinity (not really infinity), IT DEPENDS.
"One of the problems the internet has introduced is that in this electronic village, all the village idiots have internet access." - Peter Nelson
Last edited by H.G. Watson, Sr.; 11-20-2010 at 10:37 PM.
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11-20-2010, 11:54 PM #11
Re: Number of downline outlets on GFCI
H.G.
With respect sir............
Of course you are correct.
However, the context of the question clearly shows an individual who
has little or no concept of calculating electrical usage in a residential system.
So, then, what is the point of demonstrating your far reaching knowledge
by curtly, tersely, throwing out every possible variable conceivable.
This forum is created for the all inspectors
Not only those with advanced electrical knowledge.
mf
Last edited by matt faust; 11-21-2010 at 08:56 PM.
Matt Faust
Real Estate Inspector
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11-21-2010, 08:43 AM #12
Re: Number of downline outlets on GFCI
You might not agree with HG's style but to say, "Its a self serving, elitist attitude that does nothing to guide the
questioner to an answer or even a source...." is wrong. I have accumulated a lot of very good resources/documents and knowledge from this site, much of which HG has provided.
Most threads do not have yes and no answers, you will typically get simple and detailed responses, you can read them or skip over them, it's really that simple.
Ron,
How many receptacles were downstream and where are they, kitchen?
Hopefully this will keep me out of trouble for being off topic.
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11-21-2010, 09:11 AM #13
Re: Number of downline outlets on GFCI
I see no reason that a question can be shown to be rather ' complicated ' as asked ... by Hg or anyone else here. Giving a detailed answer is not necessarily directed at the original poster but to make a point to all reading the thread. At that the end of that 'point' Hg asks for additional information to 'narrow the possible answers down a bit' or at the very least understand more precisely what the op is inspecting or observing ... that prompted the question asked..
To say any number is allowed or it's a volt amp thing is restricted to IF he has the particular situation you assume he has.
Just my opinion but let Hg answer anyway he wants ... if the OP doesn't like it let him exchange his disagreement with Hg and lets move on. Again Hg asked the OP to rephrase after explaining in detail that it depends. He even gave an example of how that question could be rephrased to provide an accurate answer.
If the Op doesn't understand the details of why the question is rather 'broad' he most certainly will understand that he needs to rephrase and was given an example of how to do that ..nothing complicated there IMO.
I wholehearted disagree that this forum is designed around the ' village idiot' that is short changing your profession...!!!
Better to say all are welcome here regardless of skill level but don't expect to be treated as an idiot....
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11-21-2010, 10:08 AM #14
Re: Number of downline outlets on GFCI
I always enjoy the flow of ideas on this forum. I think my question was sufficiently answered. I had a client ask me the maximum number of outlets that could be protected downline from one GFCI outlet. It appears there is no specific code in the NEC or IRC that answers the question. I appreciate everyone's help.
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11-21-2010, 10:55 AM #15
Re: Number of downline outlets on GFCI
HG -
I it may help if you posted the NEC code article(s) your answers are based on. This way those who do not know can look it up in the NEC and read it and learn.
Also : a single receptacle is calculated the same as a duplex receptacle , they are both calculated at 180 volt-amperes. ( the same for a the ever so rare triplex outlet 180 VA)
It's when you get to the quad plex outlets that things change, they are calculated at 360 volt-amperes.
Last edited by ken horak; 11-21-2010 at 11:06 AM.
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11-21-2010, 11:11 AM #16
Re: Number of downline outlets on GFCI
Ron
I'm not certain but on a related note I believe in Canada they do have a limit of receptacles whether gfci protected or not but the cumulative total of gfci receptacles and protected receptacles and non protected receptacles is a definitive number IF the branch circuit is general purpose cord and plug only...not 100% sure how they define the requirement for the branch circuit.
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11-21-2010, 03:49 PM #17
Re: Number of downline outlets on GFCI
No.
Maybe.
Yes.
First, the "No." answer: When referring to residential installations one can have as many receptacle outlets on a circuit as one desires to have on that circuit.
Second, the "Maybe." answer: I've read, I believe someone posted it here, that one or more manufacturers stated in their installation instructions not to have more than 10 receptacle outlets downstream of a GFCI receptacle outlet device.
Lastly, the "Yes." answer: In other than residential dwellings the NEC address a load per receptacle outlet, and that load thereby limits the number of receptacle outlets. Keep in mind that a duplex receptacle outlet is "two" (hence the "duplex", meaning "two") receptacle outlets. The load for each receptacle outlet is 180 volt-amperes (except dwelling units and banks/office buildings, with banks/office buildings being the larger of 180 volt-amperes or 1 volt-amperes per square foot, which means banks/office buildings may actually have fewer receptacles per circuit).
If we use 180 volt-amperes per receptacle outlet, a 15 amp circuit would be 15 amps x 120 volts = 1800 volt-amperes / 180 volt-amperes = 10 receptacle outlets on the 15 amp circuit, and 10 receptacle outlets is 5 duplex receptacles. The same math for a 20 amp circuit: 20 x 120 = 2400 / 180 = 13.34 or 13 receptacle outlets, which is 6 duplex receptacle outlets and 1 single receptacle outlet.
However, if there is a single piece of equipment with four or more receptacles (think plug strip with four or more receptacles in it), then the calculated load shall not be less than 90 volt-amperes per receptacle, which means it 'could' still be rated as 4 x 180 volt-amperes, but there are conditions under which it 'may' be rated at 4 x 90 volt-amperes.
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11-21-2010, 04:20 PM #18
Re: Number of downline outlets on GFCI
Not to exceed 80%, the converse of 125%, for those 120V circuits' (OCPDs and equipment) not rated for use at 100% continuous (3 hr. or more):
15A multiple outlets = 1440 VA; 20A multiple outlets = 1920 VA; limit, other than residential; Hence the 8/10 duplex receptacle limits mentioned (@ 180 VA per strap) with no other loads on the circuit(s).
Last edited by H.G. Watson, Sr.; 11-21-2010 at 04:26 PM.
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11-21-2010, 04:55 PM #19
Re: Number of downline outlets on GFCI
The calculation of the loads for the receptacle outlet circuits does not take the 80% limitation into consideration on circuit . That is taken into consideration when selecting the overcurrent protection size (provided that does not exceed the maximum overcurrent protection allowed for a given conductor size.
I.e., a #14 AWG copper has a maximum overcurrent protection limitation of 15 amps, #12 AWG copper has a maximum overcurrent protection limitation of 20 amps, and #10 AWG copper has a maximum overcurrent protection limitation of 30 amps.
Added with edit: The above maximum overcurrent protection limitations are, of course (I was originally trying to keep it simple) subject to the 'unless as otherwise allowed by the code', which is what allows 40 amp breakers on #10 AWG copper for air conditioner condenser units, etc.
Last edited by Jerry Peck; 11-21-2010 at 06:48 PM. Reason: added "added with edit" part for clarity
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11-21-2010, 08:01 PM #20
Re: Number of downline outlets on GFCI
Are you saying one is only allowed to install 5 duplex receptacles on a 15 ampere circuit and only allowed to install 6 duplex and 1 single receptacles on a 20 ampere circuit?????
PLEASE POST THE CODE ARTICLE you are basing this information on !!!!
POST THE CODE ARTICLES you are using to determine the allowed number of outlets on a circuit in both a dwelling and /or a non-dwelling !!!
I've now requested BOTH JP and HG to post code articles , will they ??
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11-21-2010, 08:19 PM #21
Re: Number of downline outlets on GFCI
As you wish ...
ARTICLE 220 Branch-Circuit, Feeder, and Service Calculations
- II. Branch-Circuit Load Calculations
- - 220.14 Other Loads — All Occupancies.
- - - (I) Receptacle Outlets. Except as covered in 220.14(J) and (K), receptacle outlets shall be calculated at not less than 180 volt-amperes for each single or for each multiple receptacle on one yoke. A single piece of equipment consisting of a multiple receptacle comprised of four or more receptacles shall be calculated at not less than 90 volt-amperes per receptacle. This provision shall not be applicable to the receptacle outlets specified in 210.11(C)(1) and (C)(2).
- - - (J) Dwelling Occupancies. In one-family, two-family, and multifamily dwellings and in guest rooms or guest suites of hotels and motels, the outlets specified in (J)(1), (J)(2), and (J)(3) are included in the general lighting load calculations of 220.12. No additional load calculations shall be required for such outlets.
- - - - (1) All general-use receptacle outlets of 20-ampere rating or less, including receptacles connected to the circuits in 210.11(C)(3)
- - - - (2) The receptacle outlets specified in 210.52(E) and (G)
- - - - (3) The lighting outlets specified in 210.70(A) and (B)
- - - (K) Banks and Office Buildings. In banks or office buildings, the receptacle loads shall be calculated to be the larger of (1) or (2):
- - - - (1) The calculated load from 220.14(I)
- - - - (2) 11 volt-amperes/m2 or 1 volt-ampere/ft2
- - - (L) Other Outlets. Other outlets not covered in 220.14(A) through (K) shall be calculated based on 180 volt-amperes per outlet.
will they ??
I had actually signed off for the night too, then something drew me back ...
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11-21-2010, 08:35 PM #22
Re: Number of downline outlets on GFCI
A duplex receptacle shares a yoke or strap, Jerry Peck.Its 180 VA per duplex receptacle yoke (of which there is one, or a shared one). There is no dividing it by two.
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11-21-2010, 09:01 PM #23
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11-21-2010, 09:45 PM #24
Re: Number of downline outlets on GFCI
As I understand the subject at hand and understanding that we are discussing 'load calculations' in other than residential dwellings it does not matter how many contact devices (receptacles) are on a single yoke. A duplex receptacle has two contact devices on one yoke or a multiple receptacle. . Look at the definition of receptacle in the NEC. As an example
A single yoke with one contact device = 1 receptacle = 180 va = 1.5 amps
A single yoke with two contact devices (duplex) = 1 multiple receptacle = 180va = 1.5 amps
A single yoke with three contact devices (triplex) = 1 multiple receptacle = 180va = 1.5 amps
For a branch circuit protected by a 15 amp breaker that would be 15/1.5 = 10 device yokes with any combination of single or multiple receptacles but having not more than 3 per yoke.. Graphically it looks like this below. My files show the graphic coming from ECM magazine. I'll try to find the article and post it on this thread.
IMO I think it would be less confusing to define a receptacle as ... "a device consisting of a single yoke that has at least 1 but not more than 3 contact points to connect an attachment plug"
Just noticed the 2008 NEC Handbook has a similar graphic
Last edited by Roger Frazee; 11-22-2010 at 08:34 AM. Reason: added word multiple and IMO text and spellin .. well really I just did a lot of editing to be more clear
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11-21-2010, 09:48 PM #25
Re: Number of downline outlets on GFCI
For Canadian lurkers, in Canada, you may have up to 12 outlets on a 15 amp branch circuit. Duplex receptacles count as one outlet.
John Kogel, RHI, BC HI Lic #47455
www.allsafehome.ca
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11-21-2010, 09:58 PM #26
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11-21-2010, 10:08 PM #27
Re: Number of downline outlets on GFCI
hg
it's late 10 pm is beddy bye time for me. do you not think i didn't call my local gov when i first saw this post to see what they recommend. no electrician that i know will put more then 10+ or - 3 outlets on a 15 amp breaker. put it to sleep with all of us
cvf
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11-21-2010, 10:22 PM #28
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11-21-2010, 11:13 PM #29
Re: Number of downline outlets on GFCI
I found the link to the article containing the graphic .... as Charlie said ...GOOD NIGHT ....
Electrical Contractor: Branch-Circuit, Feeder and Service Calculations, Part VII
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11-22-2010, 01:29 PM #30
Re: Number of downline outlets on GFCI
That was a cool article Roger, Thanks for posting it.
mf
Matt Faust
Real Estate Inspector
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11-22-2010, 04:54 PM #31
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11-22-2010, 04:57 PM #32
Re: Number of downline outlets on GFCI
Roger -
Good post with that article !
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11-22-2010, 05:16 PM #33
Re: Number of downline outlets on GFCI
Yep that is a better article than most. The author did a good job.
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11-22-2010, 05:24 PM #34
Re: Number of downline outlets on GFCI
Oops ... I got carried away with the math and counted the duplex as two receptacles (it is, but is it is only counted as one for this purpose) when I was showing H. G. that you do not use the 80% factor.
H.G., read that article Roger posted, you do not use the 80% factor when doing those calculations.
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11-22-2010, 05:34 PM #35
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11-22-2010, 07:26 PM #36
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