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Ron Tipton
11-20-2010, 03:38 PM
Is there a specific number of outlets allowed downline from a ground fault protected outlet?

matt faust
11-20-2010, 04:10 PM
edited

matt faust
11-20-2010, 04:23 PM
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:cool:

CHARLIE VAN FLEET
11-20-2010, 04:55 PM
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

H.G. Watson, Sr.
11-20-2010, 08:15 PM
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?

CHARLIE VAN FLEET
11-20-2010, 08:28 PM
HG

no offense but what did you say--

cvf

H.G. Watson, Sr.
11-20-2010, 08:35 PM
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?

As mentioned - IT DEPENDS. Perhaps if you narrowed down your question a bit, and rephrased it. Do you mean to ask, is there a limitation as to the number of receptacles that may be protected load side from a combination GFCI receptacle? It too depends, ex. MWBC.

What didn't "compute"?:confused:

matt faust
11-20-2010, 09:49 PM
edited

CHARLIE VAN FLEET
11-20-2010, 10:05 PM
hg

i understood what ron was asking--it's simple. your answers are not.

cvf

H.G. Watson, Sr.
11-20-2010, 10:32 PM
hg

i understood what ron was asking--it's simple. your answers are not.

cvf

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

matt faust
11-20-2010, 11:54 PM
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:cool:

chris mcintyre
11-21-2010, 08:43 AM
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.:)

Roger Frazee
11-21-2010, 09:11 AM
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....:)

Ron Tipton
11-21-2010, 10:08 AM
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.

ken horak
11-21-2010, 10:55 AM
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.

Roger Frazee
11-21-2010, 11:11 AM
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.

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.

Jerry Peck
11-21-2010, 03:49 PM
Is there a specific number of outlets allowed downline from a ground fault protected outlet?

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.

H.G. Watson, Sr.
11-21-2010, 04:20 PM
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).

Jerry Peck
11-21-2010, 04:55 PM
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.

ken horak
11-21-2010, 08:01 PM
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.


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 ??

Jerry Peck
11-21-2010, 08:19 PM
I've now requested BOTH JP and HG to post code articles , will they ??

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 ??
Within less than 20 minutes too. :D
I had actually signed off for the night too, then something drew me back ... :cool:

H.G. Watson, Sr.
11-21-2010, 08:35 PM
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.

CHARLIE VAN FLEET
11-21-2010, 09:01 PM
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


remember my volts x amps -in post # 3--you are now onboard

Roger Frazee
11-21-2010, 09:45 PM
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

John Kogel
11-21-2010, 09:48 PM
For Canadian lurkers, in Canada, you may have up to 12 outlets on a 15 amp branch circuit. Duplex receptacles count as one outlet.

H.G. Watson, Sr.
11-21-2010, 09:58 PM
remember my volts x amps -in post # 3--you are now onboard
Except there is no such limitation or calculation made for RESIDENTIAL occupancies CVF without a local ammendment requiring same.

CHARLIE VAN FLEET
11-21-2010, 10:08 PM
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

Roger Frazee
11-21-2010, 10:22 PM
For Canadian lurkers, in Canada, you may have up to 12 outlets on a 15 amp branch circuit. Duplex receptacles count as one outlet.
Thanks John I brought that up in an earlier post but couldn't remember the details.

Roger Frazee
11-21-2010, 11:13 PM
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 (http://www.ecmag.com/?articleID=3748&fa=article)

matt faust
11-22-2010, 01:29 PM
That was a cool article Roger, Thanks for posting it.

mf:cool:

ken horak
11-22-2010, 04:54 PM
As you wish ...
ARTICLE 220 Branch-Circuit, Feeder, and Service Calculations
-
Within less than 20 minutes too. :D
I had actually signed off for the night too, then something drew me back ... :cool:

Well I'll give you 1/2 credit as you only answered 1/2 the questions :eek: :D


Oh by the way ..
That something that drew you back ---
That was the POWER I HOLD OVER YOU hahahaha

ken horak
11-22-2010, 04:57 PM
Roger -
Good post with that article !

Roger Frazee
11-22-2010, 05:16 PM
Yep that is a better article than most. The author did a good job.

Jerry Peck
11-22-2010, 05:24 PM
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


Oops :o ... 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.

Roger Frazee
11-22-2010, 05:34 PM
Oops :o ... 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.

Hi Jerry

I think you should have resisted Kens power over you and went to bed. Doing a search of the past threads over several months ... you got it right in those threads .. where the subject was being discussed....:)

John Kogel
11-22-2010, 07:26 PM
For Canadian lurkers, in Canada, you may have up to 12 outlets on a 15 amp branch circuit. Duplex receptacles count as one outlet.In Canada for a 20 amp circuit, the max is 16. These would likely be the kitchen counter outlets, 15 amp everywhere else.

Also in Canada. The only GFCI outlets needed would be both sides of the sink.

Roger, you are welcome.