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Posted By: SheBeInspector 2 GFCIs on same circuit - 09/15/08 02:53 AM
Greetings to all: A 2.5-hour search in various Forums was futile, so here's my question:
A random poll of certified home inspectors at a state association-sponsored electrical seminar revealed that many of us find "dueling" GFCIs on the same circuit. For example, if there's a GFCI receptacle in the kitchen, and another in the garage, the kitchen GFCI won't trip and/or reset as expected. We're guessing that the GFCIs are confusing each other and the downstream receptacle should be replaced. So the kitchen would get a standard receptacle (labeled that it's GFCI protected) and the garage GFCI would remain. Also, when there's a GFCI breaker in the service panel, shouldn't the receptacles controlled by that breaker also be standard, NOT GFCI receptacles to avoid "duels" as well? Lastly, we're not talking about GFCIs for bathrooms, which are clearly discussed in code books. So any info or NEC code citations you share would be most appreciated. I'll relay your explanations on our professional bulletin board so we can all be educated about this issue. Thanks so much & I'll check back with you asap.
Posted By: renosteinke Re: 2 GFCIs on same circuit - 09/15/08 03:03 AM
Welcome ... and feel free to visit our chat room!

There is really no such thing as 'dueling GFCI's." The presence of one on a circuit ought not have any effect on the others. As you might guess, the NEC does not specifically address this non-issue.

What might happen, though, is that ... due to manufacturing tolerances, accumulating leakage, etc ... that the GFI that trips may not be the one closest to the fault.

Posted By: gfretwell Re: 2 GFCIs on same circuit - 09/15/08 03:42 AM
Do you know about these guys?

http://www.nachi.org/forum/

They have discussion groups for home inspector related questions and answers that go beyond the code requirements into what your SOP will require.
Like John (Reno) says you are also welcome here.
Posted By: Scott35 Re: 2 GFCIs on same circuit - 09/15/08 06:54 AM
SheBeInspector

Welcome to ECN!

As mentioned by others, feel free to hang around and participate.
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I would like to address your original post.

Q1:
Quote

A random poll of certified home inspectors at a state association-sponsored electrical seminar revealed that many of us find "dueling" GFCIs on the same circuit.


REPLY TO Q1:

Could you define how the GFCI Receptacles are connected on this Circuit?

A:
If they are all are simply Pig-Tailed from the Circuit, with the only connections being made to the "LINE" Terminals, then there should not be any trip issues.
This is NEC Compliant, and is a way to connect GFCI receptacles across a MWBC (Multi Wire Branch Circuit).

PRO: This type of connection allows for a "Selective Coordination" of device tripping - meaning the GFCI Receptacle which was connected to the leakage (Ground Fault) is the only one that trips. All others stay latched.

CON: This type of connection is the most expensive, as each Outlet requires a GFCI Receptacle.

B:
If there is a "First GFCI Receptacle" (Homerun to this Outlet), where the incoming Branch Circuit is connected to the "LINE" Terminals, and the rest of the Circuit is connected through the GFCI's "LOAD" Terminals, any Ground fault down stream + at the "First" device will trip that "First" GFCI - even the "TEST Button" on downstream GFCI Receptacles - provided the Downstream GFCI Receptacles are wired properly.

Connecting Multiple GFCIs through the "LOAD" Terminals of another GFCI is NEC Compliant, and will work.
It is just an expensive way of doing things - very similar to example "A" above, only the devices are wired through one or more GFCIs, so there is no benefit of "Selective Coordination" in this example.

(BTW "Selective Coordination" is a term which refers to Overcurrent Protection Devices - such as Circuit Breakers and Fuses; but the basis of Selective -vs- Non-Selective Coordination applies here.)

Q2:
Quote

For example, if there's a GFCI receptacle in the kitchen, and another in the garage, the kitchen GFCI won't trip and/or reset as expected.


REPLY TO Q2:
This may be due to several factors:

1: The GFCI in the Garage is not protecting the GFCI in the Kitchen (devices only connected to "LINE" side Terminations),

2: The Garage GFCI is on a different Circuit from the Kitchen Circuit(s),

3: There is a MWBC feeding the Kitchen, and the GFCIs are connected through "LOAD" Terminals,

4: The Circuit between the Garage Receptacle and the Kitchen Receptacle undergoing the Test has an Open Conductor in the Branch Circuitry (or other wiring errors),

5: One of the GFCIs is malfunctioning,

6: The GFCI in the Kitchen does not have 120VAC at it - likely to occur if the "Upstream GFCI" has tripped, and this "Downstream GFCI" is connected to it via the Upstream Device's "LOAD" Terminals.

If there is no active Circuit available at the GFCI Receptacle, the "TEST" Button does not function, and if the "RESET" Button has already perfored a reset (Re-latch), that Button will not do anything.

This scenario would require a voltage Test at the Kitchen Device, to confirm the Circuit is active.
If 120VAC is read between the two Vertical Terminals of the Receptacle, and the "TEST" Button is not functioning, the device may be defective.

There is more to this, so let me know what the parameters are.


Q3:
Quote

We're guessing that the GFCIs are confusing each other and the downstream receptacle should be replaced. So the kitchen would get a standard receptacle (labeled that it's GFCI protected) and the garage GFCI would remain.


REPLY TO Q3:

That would be one way to do it, which would be NEC Compliant.

Another way is to wire the GFCI Receptacle at the Garage so it only connects through the "LINE" Terminals - the Device "Taps Off " the Branch Circuit; then the Branch Circuit continues "As-Is" to the Kitchen Outlet, where another GFCI Receptacle would be installed + connected through the "LINE" Terminals only.

If there are additional Kitchen receptacles "Downstream":
The "First Outlet" at the Kitchen would have a GFCI Receptacle, with the remaining Kitchen Outlets being Standard Receptacles - which are connected through the "LOAD" Terminals of the GFCI at the Kitchen.


Q4:
Quote

Also, when there's a GFCI breaker in the service panel, shouldn't the receptacles controlled by that breaker also be standard, NOT GFCI receptacles to avoid "duels" as well?



REPLY TO Q4:

They MAY be Standard Receptacles, or if someone wants to do so, they MAY also be GFCI Receptacle Devices.
Both methods are NEC Compliant.

There is a "DESIGN ISSUE" with GFCI Receptacles fed from a GFCI Breaker, which results in "Non-Selective Coordination" when one GFCI Receptacle undergoes a TEST; both the GFCI Receptacle AND the GFCI Breaker may trip.

Other than that minor design issue, this would likely be the most effective way to provide Ground Fault Protection to Personnel.


Q5:
Quote

Lastly, we're not talking about GFCIs for bathrooms, which are clearly discussed in code books. So any info or NEC code citations you share would be most appreciated.


REPLY TO Q5:

I did not mention this before, as I am not too sure about the "Kitchen Receptacle" being used as an example here.

If the Kitchen Receptacle is one of the "Small Appliance Branch Circuits", as defined in NEC Article 210.11(C), connecting the Garage Receptacle to this would not be Compliant.
210.52(b)(2) specifies these Branch Circuits are not to have any other outlets, which eliminates the Garage Outlet.
The only exceptions are for an Electric Clock in any of the Rooms covered in 210.52, or a receptacle for Gas Ignitors + Lighting of Cooking Equipment.

The Rooms which the "Two Or More Small-Applinace Branch Circuits" include are:
* Kitchen,
* Pantry,
* Breakfast Room,
* Dining Room,
* Similar Areas (areas related to Kitchen activities).


Q6:
Quote

I'll relay your explanations on our professional bulletin board so we can all be educated about this issue.


REPLY TO Q6:

Great!

Tell them to feel free in discussing these items here.


Q7:
Quote

Thanks so much & I'll check back with you asap.


REPLY TO Q7:

Looking forward to your replies!

Hope these replies are useful.

Scott
Posted By: SteveFehr Re: 2 GFCIs on same circuit - 09/15/08 11:26 AM
As already pointed out, series-connected GFCI outlets are not a violation. Maybe a waste of a $12 GFCI where a $1 receptacle would do, but there's certainly nothing wrong with it. In fact, it's even safer, as it hedges against GFCI failure. One GFCI will always trip before the other, it's just the nature of how they work.

One way to test both GFCI outlets is to simulate a N-G fault, which will route a small amount of building neutral current through the ground wire and *should* trip both GFCI receptacles. I'd caution that a properly listed device should be used for this, as it's dangerous to simply short the wires- there could be a LOT of current on the building neutral, and you don't want to route that through a #14 wire.
Posted By: KJay Re: 2 GFCIs on same circuit - 09/15/08 02:29 PM
Steve,
I will give insert my two cents worth and then shut my mouth.
IMO, the series installation in OP post is indeed a basic violation of NEC 110.3[B].
None of the manufactures instructions I have seen for UL listed GFCI receptacles or cb’s allow this type of connection. Generally they have only two approved connection methods and this is not one of them. I think the fact that they are having issues with proper tripping of the devices reinforces this.
Of course, this is JMHO.
Posted By: SteveFehr Re: 2 GFCIs on same circuit - 09/15/08 03:25 PM
KJay, I disagree, this is not a violation of NEC 110.3. The method of ground fault, overload or overcurrent detection at any point upstream has no bearing on the listing. A GFCI receptacle is no different than ground fault detection on a switchboard, or the ground fault detection integrated into an AFCI breaker, both of which are unquestionably acceptable to feed a GFCI receptacle.
Posted By: KJay Re: 2 GFCIs on same circuit - 09/15/08 04:51 PM
Steve, I clearly see your point.
But, my only contention was that this receptacle contains ground fault protection for persons [GFCI] with instructions that clearly show connection diagrams with only other non-gfci receptacles connected downstream of it. IMO, installing a second GFCI receptacle downstream of this first GFCI receptacle would be a violation of the listed instructions included with this first receptacle.
This is no way should be construed as saying that you couldn’t have another piece of listed equipment with its own GFCI protection utilized downstream, but I don’t believe that a second GFCI receptacle would be allowed, at least according to the included instructions.
Posted By: electech Re: 2 GFCIs on same circuit - 09/15/08 05:20 PM
"I will give insert my two cents worth and then shut my mouth."

Easier said than done! (I know how that is...)

The NRTL Listing report may contain specific paragraphs taken from the manufacturer-submitted user documentation. This would be to prove safety standard compliance in the case where a safety standard clause states the user documentation must present certain specific information. These instruction are typically minimums. Other installations may not violate a listing.

In this case, UL943 clause 8.1 details what needs to be stated. "8.1.1 There shall be plain, legible, and durable instructions for effective use of a ground-fault
circuit-interrupter" I don't want to post too much for copyright reasons, but clause 8.1.x directs you to annex E for some specific required info: MFG name, "To prevent electric shock or electrocution, always turn the power off...", "Do not install this GFI receptacle on a circuit that powrs life support...", etc. I don't see anything disallowing mutliple GFI's, but I don't have time to look right now. This is lunch break and I have some important cigarettes I need to smoke. Probably too busy at work today, but I'll browse the standard tonight (if I don't get too distracted at home).
Posted By: SheBeInspector Re: 2 GFCIs on same circuit - 09/15/08 06:30 PM
It's a thrill to be runnin' with the big dogs! Thanks for your replies, and I apologize for my vague, incorrect and/or sloppy electrical nomenclature. I'll work on it. Now, back to the "dueling" GFCIs:
I found separate breakers for the kitchen & garage in the service panel and the kitchen countertop GFCI tested as 120v, "wiring OK" with my Sure-Test, as did the garage GFCI.
Posted By: SheBeInspector Re: 2 GFCIs on same circuit - 09/15/08 07:41 PM
Oops, I just realized pressing "tab" key posts the comment. Sorry about the previous incomplete message.
So if there's only 1 GFCI in the garage, and 1 GFCI in the kitchen (on the countertop), does that kind of hint they're improperly on the same circuit despite the separate breaker labels in the service panel? The GFCIs didn't affect any other outlets either in the kitchen or garage.
What bothers me is someone tripping the garage GFCI, which in turns trips the kitchen counter GFCI where the crock pot has been running with the evening's beef stew. Resetting the garage GFCI is forgotten, as it doesn't affect any other outlets, so the kitchen GFCI remains without power all day and brews a poisonous meal.
It just doesn't seem right. So I'm grappling with how to report this condition and will keep following this thread so I can convey your perspectives to my colleagues at our regular association meeting. Thanks!
Posted By: gfretwell Re: 2 GFCIs on same circuit - 09/15/08 08:30 PM
You certainly have a problem, since the kitchen counter receptacle circuit "shall have no other outlets".

As for chaining GFCIs it can't be helped of you use equipment with a GFCI in the plug outside where the receptacle also requires GFCI. My boat lift and pressure cleaners work just fine this way.
Posted By: Tiger Re: 2 GFCIs on same circuit - 09/15/08 11:29 PM
If the garage GFCI trips the kitchen GFCI there's a problem with the wiring.Kitchen countertop circuits aren't allowed to come from the garage, or go from the kitchen to the garage. If there were a failure to trip I'd comment that the GFCIs manufactured before 2003 have a high failure rate, approx. 50%. I suspect a miswired multi-wire branch circuit, or an outlet extended from the kitchen to the garage is the issue, but it'll take an electrical contractor to sort it out.
Posted By: Scott35 Re: 2 GFCIs on same circuit - 09/20/08 07:14 AM

SheBeInspector

Welcome back!

Glad the information posted was helpful.

In addition to the other Members' posts, I will address your latest reply.

Q1:

Quote

It's a thrill to be runnin' with the big dogs! Thanks for your replies, and I apologize for my vague, incorrect and/or sloppy electrical nomenclature. I'll work on it.


REPLY TO Q1:

No problem with the terms.
There is only one way to become "Fluent" in this Trade, and that is to study!
Coming here to ECN and asking questions will benefit your studies greatly.

Q2:

Quote

Now, back to the "dueling" GFCIs:
I found separate breakers for the kitchen & garage in the service panel and the kitchen countertop GFCI tested as 120v, "wiring OK" with my Sure-Test, as did the garage GFCI.


REPLY TO Q2:

Great.
That's what I was hoping to hear (actually "See"...)



Q3:

Quote

So if there's only 1 GFCI in the garage, and 1 GFCI in the kitchen (on the countertop), does that kind of hint they're improperly on the same circuit despite the separate breaker labels in the service panel? The GFCIs didn't affect any other outlets either in the kitchen or garage.


REPLY TO Q3:

Not really.

The way to find out if the Circuit marked "Garage" also feeds the Kitchen would be to turn off the Circuit Breaker in the Panelboard marked "Garage", then see if any of the Kitchen Outlets are de-energized.
Check them prior to turning off the Breaker to verify that they are indeed energized.

If the "Garage" Circuit also turns off Kitchen Outlets (or other outlets), then it may be likely that when the GFCI Receptacle trips, these outlets on the same Circuit will be affected - as they would be protected by that GFCI.
This would have to be verified by re-energizing the Circuit, pressing the "TEST" Button on the Garage GFCI Receptacle, then testing the Outlets to see if they are energized.

The only way to verify Circuitry is to physically test by turning off given Circuit Breakers per the Identified Circuit in the Circuit Directory, then testing the Outlets with the proper testing equipment.

Be sure your testing equipment is in good operating order, is correct for the tests to be performed, and is Certified for the Voltages to be applied to (such as CATIII).

***** DISCLAIMER + SAFETY MESSAGE *****

While I am on the subject of proper test equipment, I really need to make the following statement regarding Personal Safety around Energized Electrical Equipment:...

There is no need to remove any Panelboard Covers, or any Receptacle Devices to perform these tests.
Please do not let _ANYONE_ remove Panelboard Covers, devices (Receptacles), or talk you into removing any of these things.
There is no need to remove these items, and in order to perform the tests correctly, these items must be in place.
Besides, there is just too much danger involved with Live exposed parts: Shock, Burns, Arc Faults from Short Circuits causing permanent injury, major Burns, blindness, even death!

If, for any reason - at any time, you do not feel comfortable or confident in performing any tests, or being around Energized Electrical Equipment, DO NOT PERFORM THE TESTS!!!
Request a Qualified Individual to perform the testing.

Believe me, even a simple test may result in an explosive Fault (Short Circuit), or someone getting stuck to an Energized Circuit without being able to let go, or let anyone know they are being shocked - until that Person loses conscienceness (normally by then it is too late).

I am not trying to be an Ass (pardon the language), I just want to make this known.
This applies to anyone.

OK, Soapbox Mode is "OFF" now, so back to the replies!!!

Q4:

Quote

What bothers me is someone tripping the garage GFCI, which in turns trips the kitchen counter GFCI where the crock pot has been running with the evening's beef stew. Resetting the garage GFCI is forgotten, as it doesn't affect any other outlets, so the kitchen GFCI remains without power all day and brews a poisonous meal.


REPLY TO Q4:

Yes, this is a valid issue, however it is outside the SCOPE of the NEC , as the minimum safety compliance has been met.
This is what would be known as a "DESIGN ISSUE"

The exception here being that the Garage Receptacle is included with the "Small Appliance Branch Circuits"(SABC), of which there are a minimum of Two (2) intended for the Kitchen Counter area.
These SABC's may also feed outlets in the "same area" as the Kitchen.

Refer to NEC Article 220 for complete information per the SABCs

If the Garage Receptacle (or any other outlets not in the listed areas) is included with the SABCs, this would be nonconformance to NEC Article 220, and would be a Code Violation.... provided:
  1. The Dwelling is subject to the NEC,
  2. The Dwelling was built prior to the 2 SABC Restrictions,
  3. There are already 2 SABC at the Kitchen


One must be familiar with the NEC Version used during the time a given Structure was built, along with criteria involved with a remodel. In addition, what the AHJ uses as "Model Code" - if any Code is observed.

Q5:

Quote

It just doesn't seem right. So I'm grappling with how to report this condition and will keep following this thread so I can convey your perspectives to my colleagues at our regular association meeting. Thanks!


REPLY TO Q5:

Please review this latest message, and if you have any questions or comments, feel free to post them here.
You may also contact me via Private Message if you wish to.

Good luck with everything.

Scott
Posted By: deverson Re: 2 GFCIs on same circuit - 09/20/08 03:23 PM
Although the current and last bunch of cycles of the code do not permit it, having an outside recp on a kitchen circuit was accepted and approved as an exception of the NEC. I don't have old code books but I do remember that being OK. I personally would rather have more GFCI's that are there to protect personal and property than seeing 200 feet of underground wire being protected in a conduit full of water and having the HO want those GFCI's removed because nuisance tripping.
Dave
Posted By: sparkyinak Re: 2 GFCIs on same circuit - 09/20/08 03:31 PM
Originally Posted by SheBeInspector
For example, if there's a GFCI receptacle in the kitchen, and another in the garage, the kitchen GFCI won't trip and/or reset as expected.

Can it be confirmed that if there is power or not when the gfci will not trip? A GFCI will not reset if there is not power to it. In general, you can put multiple gfci's inline and one will not effect the other.
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