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Thread: Mis-wired GFCI?
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10-19-2007, 07:39 PM #1
Mis-wired GFCI?
An older home I inspected last summer had no grounded outlets. There were GFCI's where needed, but none tripped when using the trip button on my three light tester. I wrote it up as needing repair. Buyer had an electrician look at it and wrote to the lender "GFCI in working condition but not on a 3 wire system." Lender wants me to answer how this affects code and safety issues. I'm no sparky but I feel it is a code violation and a safety issue. Any thoughts would be appreciated.
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10-19-2007, 07:56 PM #2
Re: Mis-wired GFCI?
A properly wired (or improperly wired) GFCI won't trip on a two wire (ungrounded) circuit when tested with a 3-bulb tester having a GFCI trip button on it. The GFCI receptacles on a two-wire circuit can still provide personal protection against shock or electrocution hazards, but they don't provide an equipment ground. Therefore, it is still beneficial to convert older receptacles in the proper locations to GFCI type, but there is no equipment ground. A 3-bulb tester won't trip them.
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10-19-2007, 08:10 PM #3
Re: Mis-wired GFCI?
Duane,
The proper way to test that outlet is with the test button on the receptacle. Did you try it??
rr
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10-19-2007, 09:11 PM #4
Re: Mis-wired GFCI?
Richard,
I didn't try the test button on the outlet, just the black button on my three light tester.
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10-19-2007, 11:07 PM #5
Re: Mis-wired GFCI?
Duane,
If your using the plug in three light tester that costs about ten bucks from Lowes or Home Depot, then I recommend you purchase a "Sure Test" tester or another similar testing device. Those inexpensive testers are not the most reliable.
Do a search on here for testers. I think you'll find a lot of info.
By the way, welcome to the forum.
Just my two cents.
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10-20-2007, 05:24 AM #6
Re: Mis-wired GFCI?
while I agree on the Sure test unit, I have and use on, it will not trip a GFCI on a two wire or ungrounded system either. It is still recommended that the outlet test button be used. Had two in the last inspection that would not trip even with the test button.
These can be defective or just wired wrong, either way call it out for the sparkies.
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10-20-2007, 06:06 AM #7
Re: Mis-wired GFCI?
In ALL cases, the GFCI should trip when the test button on the outlet is pushed. On 2-wire circuits, it's the only way it will trip.
I use my tester button all of the time. If an outlet doesn't trip, then I try the outlet test button. Once in a while, my Suretest will give an odd reading (such as hot/ground reversed). I then try the outlet button, and a lot of the times, the Suretest will then show a correct reading.
The bottom line is - Use the outlet test button for the final answer.
JF
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10-20-2007, 07:50 AM #8
Re: Mis-wired GFCI?
The proper way to test a GFCI is to use the button on the unit, not a plug-in tester.
The GFCI functions by constantly monitoring the current on the hot and the neutral (grounded) conductors. When it sees that there is current "missing" above the trip threshold, the GFCI trips and opens the circuit. When you use the test button on the GFCI device, it energizes a circuit that is built into the device which mimics this current loss, causing the GFCI to trip. This is completely independent of the grounding conductor, and a GFCI does not need a grounding conductor in order to function properly.
The lack of a grounding conductor is a completely different issue. Its purpose is to provide a safe path for current to return to ground if for some reason it is not traveling on the grounded conductor. Having stray current looking for a ground is a dangerous thing. The grounding conductor is there to provide a good path back to the panel, instead of going somewhere else.
When you push the button on your plug-in tester, it is trying to create a ground fault by shunting current to the ground pin on the plug. If there is no grounding conductor connected to the GFCI receptacle, pushing the button on your plug-in tester does nothing, because there is no place for the current to travel. Since no current is lost, the GFCI will not trip.
Writing up the GFCI as defective based on using your plug in tester was a bad call. The right call would have been to have point out that even though the GFCI receptacle has three prongs, the ground is not connected (as the electrician has done). When used in this situation, the GFCI receptacles are required by code to be labeled "no ground" -- were they?
Then write up why having three slot receptacles with open grounds is not a good thing. Here's my boilerplate on that issue.
"There are many three-slot receptacles used at outlets in various locations throughout this home that when tested indicate an open ground. Ungrounded three-slot receptacles are a potential hazard, because there is nothing to prevent the average user from plugging into the receptacle an appliance or equipment that must have a grounding conductor for its proper and safe operation. You can easily identify this equipment because it comes from the factory with a three-prong plug installed on the cord. Correction of these open grounds by a qualified electrician is necessary to reduce these hazards. Be aware that correcting these receptacles may require the addition of new branch circuit wiring with grounding conductors if a proper means to ground the receptacles is not present at the existing outlet boxes."
Bottom line -- installing a GFCI on a two wire branch circuit will protect people from being electrocuted. But if you plug a three prong plug into a GFCI receptacle that has an open ground, equipment that relies on that ground is not properly protected from damage.
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10-20-2007, 08:01 AM #9
Re: Mis-wired GFCI?
Thanks for all the replys. You have answered the question about personal safety issues. The other half of the lenders question is about code compliance. Any thoughts there?
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10-20-2007, 08:02 AM #10
Re: Mis-wired GFCI?
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10-20-2007, 09:32 AM #11
Re: Mis-wired GFCI?
The purpose of the equipment ground conductor is to provide a low resistance path back to the transformer by way of the service neutral, not ground (earth). There is also a path back to the transformer by way of the earth, assuming there are intact grounding electrodes and conductors at the house and the transformer, but the earth path is high resistance and won't allow enough current to flow to trip a breaker.
"There is no exception to the rule that every rule has an exception." -James Thurber, writer and cartoonist (1894-1961)
www.ArnoldHomeInspections.com
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10-20-2007, 10:23 AM #12
Re: Mis-wired GFCI?
More correctly stated, the above should read:
The purpose of the equipment ground conductor is to provide a low resistance path back to the SUPPLY SOURCE.
This via the equipment grounding conductor to the service equipment, where the equipment grounding conductor is bonded to the neutral, then via the neutral conductor back to its SOURCE.
There is also a higher resistance path back to the SOURCE by way of the earth, assuming there are intact grounding electrodes and conductors at the house and the SOURCE, however, the earth path, being a higher resistance path than the neutral, and won't allow enough current to flow to trip a breaker AS QUICKLY.
The "source" is not always a "transformer", and, enough current can flow through the earth ground path to trip a breaker, it just has to overcome a higher resistance to do so.
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10-20-2007, 10:39 AM #13
Re: Mis-wired GFCI?
Correct, that's what it is for.
But if you plug a three prong plug into a GFCI receptacle that has an open ground, equipment that relies on that ground is not properly protected from damage.
However, when working in sensitive electronic settings, grounding is a must (an equipotential ground plane) to avoid ground loops and 'grounds' at different potentials, which could damage sensitive equipment in that way and from static charges, but for equipment found in most dwelling units and businesses (other than computers and other sophisticated electronics). This simply shows that there are exceptions to every rule.
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10-20-2007, 02:54 PM #14
Re: Mis-wired GFCI?
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10-20-2007, 03:51 PM #15
Re: Mis-wired GFCI?
I forget who it was that posted about 5 or 6 years ago that an inexpensive means of grounding an ungrounded wiring system was to "theoritically" replace all two prong outlets with gfci's...
I didn't like that then and I don't much like it now. But, if one was so inclined to do so, "theoritically" this would be a *Grove* upgrade.
RR
(and yes, I was in the Grove today!! )
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10-20-2007, 06:07 PM #16
Re: Mis-wired GFCI?
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10-20-2007, 06:48 PM #17
Re: Mis-wired GFCI?
John & Jerry, regarding purpose of EGC to return current back to source: I agree. Good catch. It was a long post and I didn't realize I slipped "ground" in there when I posted. Mea culpa.
Jerry, regarding EGC protecting equipment: there too, I agree that the major purpose of providing the EGC is to protect people. But, as you pointed out, there is some equipment (e.g. sensitive electronics & computers) that also need the EGC to protect the equipment. Perhaps I didn't convey it clearly in my post, but I was referring specifically to this kind of equipment when I was writing that part of the post. I was trying to explain that putting a GFCI on a two conductor circuit would take care of the "people protection" role of the EGC but it will not provide any protection of the equipment (assuming you are plugging in the type of equipment that needs protection of an EGC).
Thanks guys for the comments. I learn and get better by sticking my neck out and posting, knowing that many here are putting it under the microscope. I want to get it right and I want to improve my skill at communicating this kind of info in writing. This board is a great resource for both of those things and I'm grateful for it.
Brandon
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10-21-2007, 04:41 AM #18
Re: Mis-wired GFCI?
badair http://www.adairinspection.com Garland, TX 75042
Commercial-Residential-Construction-EIFS-Stucco-ACMV-Infrared Thermography
life is the random lottery of events followed by numerous narrow escapes...accept the good
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10-21-2007, 04:57 AM #19
Re: Mis-wired GFCI?
Back to the thread.
This may be a little less confusing
Ungrounded electrical outlets
badair http://www.adairinspection.com Garland, TX 75042
Commercial-Residential-Construction-EIFS-Stucco-ACMV-Infrared Thermography
life is the random lottery of events followed by numerous narrow escapes...accept the good
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10-21-2007, 08:44 AM #20
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10-21-2007, 10:38 AM #21
Re: Mis-wired GFCI?
Brandon,
Just clarifying, though, the ground for sensitive electronic equipment is not related to 'protection of the equipment' from the circuit, ground faults, or other such problem, but to help protect against static build-up and static charges (people walking across carpet then touching the equipment) which need to be bled off.
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10-22-2007, 05:57 AM #22
Re: Mis-wired GFCI?
Just a thought but Duane, was the "GFCI not grounded" or "Ungrounded GFCI" sticker affixed to the outlet? I recommend these be affixed in conditions with 2 wire systems and I believe (could be wrong) that this is still a requirement.
JP may correct me
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10-22-2007, 11:10 AM #23
Re: Mis-wired GFCI?
Or back you up.
406.3 General Installation Requirements.
- (D) Replacements. Replacement of receptacles shall comply with 406.3(D)(1), (2), and (3) as applicable.
- - (1) Grounding-Type Receptacles. Where a grounding means exists in the receptacle enclosure or a grounding conductor is installed in accordance with 250.130(C), grounding-type receptacles shall be used and shall be connected to the grounding conductor in accordance with 406.3(C) or 250.130(C).
- - (2) Ground-Fault Circuit Interrupters. Ground-fault circuit-interrupter protected receptacles shall be provided where replacements are made at receptacle outlets that are required to be so protected elsewhere in this Code.
- - (3) Nongrounding-Type Receptacles. Where grounding means does not exist in the receptacle enclosure, the installation shall comply with (a), (b), or (c).
- - - (a) A nongrounding-type receptacle(s) shall be permitted to be replaced with another nongrounding-type receptacle(s).
- - - (b) A nongrounding-type receptacle(s) shall be permitted to be replaced with a ground-fault circuit interrupter-type of receptacle(s). These receptacles shall be marked “No Equipment Ground.” An equipment grounding conductor shall not be connected from the ground-fault circuit-interrupter-type receptacle to any outlet supplied from the ground-fault circuit-interrupter receptacle.
- - - (c) A nongrounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied through a ground-fault circuit interrupter. Grounding-type receptacles supplied through the ground-fault circuit interrupter shall be marked “GFCI Protected” and “No Equipment Ground.” An equipment grounding conductor shall not be connected between the grounding-type receptacles.
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10-28-2007, 08:56 PM #24
Re: Mis-wired GFCI?
Just curious, why would anyone want to run an equipment ground from an ungrounded GFCI receptacle to another outlet supplied by the GFCI? Also, assuming both, in this case, to be ungrounded to start with, what would it harm if they did?
Secondly, why would they permit non grounding type receptacles to be replaced with a grounding type when protected with a GFCI? Even if marked "No equipment ground", people will certainly use them for three prong plugs. As noted above, this can still permit static charges to build up in sensitive electrical equipment such as computers. Just doesn't seem like a good idea....
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10-29-2007, 04:48 AM #25
Re: Mis-wired GFCI?
"Secondly, why would they permit non grounding type receptacles to be replaced with a grounding type when protected with a GFCI? Even if marked "No equipment ground", people will certainly use them for three prong plugs."
GFCI are designed to protect people, not equipment ( IE computers from static). The downstream 3 (or 2 prong) outlet will be protected by the GFCI even without a grounding conductor. Since a lot of today's appliance's use a 3 prong outlet, if only a 2 prong outlet is available then some people will remove the ground prong on the appliance or use an adepter. Having the 3 prong outlet will provide the same protection without having to use an adaptor or removing the ground prong on the appliance.
' correct a wise man and you gain a friend... correct a fool and he'll bloody your nose'.
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10-29-2007, 05:35 AM #26
Re: Mis-wired GFCI?
Fred,
In both instances you are referring to, a two-wire non-grounding type receptacle is being replaced with a three-wire grounding type receptacle.
In one of those instances, the replacement grounding type receptacle is a GFCI device, and in the other instance the grounding type receptacle is protected by a GFCI device, i.e., the first receptacle mentioned.
This protects, as Rick said, "people".
An equipment ground is not allowed to be run between them as it is really not an equipment ground (it is not connected to ground at the service) and 'could' either intentionally or accidentally make contact with "ground", which would create a second ground path and cause voltage drop over the ground path, which would put voltage on that 'ground' wire.
Why would someone do it? Thinking they were actually adding a 'ground' for the equipment.
Would, or shall I say 'could', it actually work? Sure, it 'could', but it also likely could, or shall I say 'would', not work and it 'could' produce and create other problems.
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10-29-2007, 06:00 AM #27
Re: Mis-wired GFCI?
Most, if not all inspection standards of practice that I am aware of state that home inspectors do not address code. That is usually considered the jurisdiction of the state or local authorities and is not something we are supposed to get involved in. It just so happens that many of the things we report are based on code, but never stated as such. We inspect and report on the basis of safety, structural integrity, durability and livability, which may or may not, necessarily also be code. I will never use the word "code" or make references to it in a report. At least that is the rule in Oregon.
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10-29-2007, 06:25 AM #28
Re: Mis-wired GFCI?
Brent,
What source do you use to document, support, or back up your reports?
Surely you, like most (if not all) the rest of us, have sellers, agents, builders saying 'what the inspector said is wrong and is not required, I don't have to do that', right?
If not, what is your secret?
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10-29-2007, 07:31 AM #29
Re: Mis-wired GFCI?
I'm at a little bit of a loss to answer this because it almost never comes up. I've been trying to remember a case, but can't. Maybe it's because of the wording I use in my reports and verbally. I never use words like required, must or should. I don't have the authority or mandate to do so. I use "recommend" a lot. If it is really important I will say Highly or strongly recommend. If it is less important I might say "it is advised, or consider doing this". I also use qualifiers like: "for added safety, to increase structural strength, or to assist in...", etc. I may also use a statement like "This is not done in accordance with accepted, or modern building standards". I know it is all semantics, but it seems to be effective. If there is a technical question I will quote the manufacturer's requirements or instructions, which, I believe trump code anyway. I never try to give the impression that anything HAS to be done, but, rather that I am identifying areas of concern and the possible consequences if they are not taken care of. Whether anything is done about them is none of my business. That is up to the parties involved in the transaction.
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10-29-2007, 12:34 PM #30
Re: Mis-wired GFCI?
Actually, they *ARE* code.
When the code says to install something per the manufacturer's installation requirements, listing and labeling, etc., those references *become part of the code*.
Thus, you are referencing code.
The rest of your post and the wording you use - I will not comment on it.
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10-29-2007, 01:56 PM #31
Re: Mis-wired GFCI?
I believe that you have a bit of Misconception Brent. To simply say that we are not "Code" inspectors is not correct. What we are not is "Code Enforcement". Additionally the local AHJ does NOT have the authority to be the final say and in fact may be derilect of duty for knowingly allowing requirements adopted by city ordinance to go overllooked. Code enforcement has the authority of the local governing body to see that contractors and home owners comply with locally adopted ordinance. They are charged to do just that.
We,,,,inspectors,,,,are our clients representative hired to provide them with conditions of the home they consider purchasing.
We have many things to back us up in our service. Experience, Training, Locally adopted codes, Manufacture instructions, Common building practices,,etc. and should use every one of them we have available to do so.
Rather you want to state actual code in your report is a decision you must make depending on your local and state laws and your attorney. I know of no national organizations that prohibit the use of or the refrencing to actual code. Someone however may have a local or state org that does, I could not tell you.
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10-29-2007, 08:43 PM #32
Re: Mis-wired GFCI?
How I test a GFCI on an ungrounded circuit: Take the Wiggy http://www.squared.com/us/products/machine_safety.nsf/unid/58870E11543C976885256D500050927B/$file/wiggy.htm and insert one probe into the hot/line side slot and then the other probe to the faucet (usually brass). If wired correctly, the GFCI will trip.
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10-30-2007, 05:31 AM #33
Re: Mis-wired GFCI?
Joe,
Proper method for testing a GFCI device on an UNgrounded circuit:
Press the 'Test' button on the GFCI device.
Proper method for testing a GFCI device on a grounded circuit"
Press the 'Test' button on the GFCI device.
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Proper way to check to see what receptacles are protected by a GFCI on an UNgrounded circuit:
Check all receptacles for power, press the 'Test' button on the GFCI device you suspect is protecting them, check to see which receptacles no longer have power. (Side note: A voltage sniffer makes quick and short work for checking the receptacles for power before and after 'tripping' the GFCI off.)
Proper way to check to see what receptacles are protected by a GFCI on a grounded circuit:
Check all receptacles for power, press the 'Test' button on the GFCI device you suspect is protecting them, check to see which receptacles no longer have power. (Side note: A voltage sniffer makes quick and short work for checking the receptacles for power before and after 'tripping' the GFCI off.)
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Proper way to check to see if a *specific* receptacle is protected by a GFCI on an UNgrounded circuit:
Check that receptacle for power, press the 'Test' button on the GFCI device you suspect is protecting that receptacle, check to see if that receptacle no longer has power.
Proper way to check to see if a *specific* receptacle is protected by a GFCI on a grounded circuit:
Check that receptacle for power, press the 'Test' button on the GFCI device you suspect is protecting that receptacle, check to see if that receptacle no longer has power.
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Home inspectors SHORTCUT METHOD for checking GFCI protection at other than the GFCI device itself on GROUNDED circuits: Plug the GFCI tester in and press the test button.
Also works as a SHORTCUT METHOD for testing the GFCI device itself, except that it is not a "short cut" as it takes longer. On older GFCI devices, this worked to identify GFCI devices which were wired backward with line/load reversed.
Last edited by Jerry Peck; 10-30-2007 at 05:38 AM.
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11-01-2007, 12:56 PM #34
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11-01-2007, 04:55 PM #35
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