GFCI

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I had a contrator put in a BBQ area and pergola for me. A couple of weeks ago the lights stopped working. The contractor sent the electrician who did the original electrical installation to fix it. He pressed the GFCI button and the lights work again. I asked him what the cause of the GFCI resetting and he said "they do that". I think it was just a symptom of another problem, possibly related to the heavy rain that we have had recently (as is usual in Texas).
Is GFCI designed to spontaneously reset? If not, what is the cause of this?
Thanks!
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No, they reset when you push the reset button. They will trip if water gets into the wireing.
--
Rich Greenberg Marietta, GA, USA richgr atsign panix.com + 1 770 321 6507
Eastern time. N6LRT I speak for myself & my dogs only. VM\'er since CP-67
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Sometimes they do that.
Could have even been excessive moisture from the rains.
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is installed correctly. Sorry, don't mean to sound confrontational, but a GFCI tripping is an indication that something went wrong whether it was water or whatever that caused it to trip. They don't "just do that" for no reason. They would be useless in such a case.
Since this is a new installation, and assuming the user did nothing to cause the problem, that electrician needs to check out his work, or possibly an inspector. It does make sense that it was posibly water getting in somewhere, but it shouldn't have done so. "They do that" is an unacceptable resonse from the electrician. It's quite likely that if you don't call him on it now, you may well be calling him later, like after he won't warranty the work any longer due to time. Even if he says there's nothign he can do, by submitting a complaint, he's been put on notice so that when the problem IS aboe to be solved, he'll still be responsible for doing so. And actually, if he's worth his salt, there is something he can do.
HTH,
PopS
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As I pointed out. Sure, there was a reason, but the conditions may have changed ten minutes later and the real cause is never found. Excessive moisture across a plug can do it. That means it is working as it should.
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wrote in message

No, I don't think that's what it means. I think the contractor's glib response that they'll "do that" is out of line and indicative that he knew where the water got in. His response was out of line for a professional, if the facts are all as stated.
PopS
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Pop ( snipped-for-privacy@devnull.spamcop.net) said...

Sorry to burst this bubble, but GFCIs can trip for what *appears* to be "no reason", and this is why codes never make them manditory for outlets used for refrigerators.
Transient noise on a power line can cause GFCIs to trip, however I suspect it would be EXTREMELY rare for such noise to trip a GFCI that did not have a load on it at the time. Since the original poster mentioned lights that stopped working, it sounds to me that the lights are downstream from the GFCIs and could possibly have been a load on it when a transient (spike) hit it.
Transients are high frequency noise on the power line, and high frequencies propogate slowly (relative to the speed of light) down a transmission line, which the power line would serve as. GFCIs work by detecting a difference in current between the line and neutral. The slow propogation of a spike can lead to a sensitive GFCI to detect an imbalance long enough for it to trip.
This would *appear* as a "no reason" trip, yet there is a reason. It is just not a safety reason.
I once knew someone who had a pool pump on a GFCI and claimed that every lightning storm his pool was "hit by lightning" because the GFCI would trip. LOL -- if his pool was hit, his problem would be a lot greater than just resetting the GFCI! The electrical storm was causing transients on the power lines in the area that were the cause of the GFCI tripping.
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Calvin Henry-Cotnam
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I suspect, rather than line transients, it was actually _ground_ transients inducing current in the line.
--
Chris Lewis, Una confibula non set est
It\'s not just anyone who gets a Starship Cruiser class named after them.
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Chris Lewis ( snipped-for-privacy@nortelnetworks.com) said...

Could be, but the point was that it was not a ground _fault_ that was really happening.
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Calvin Henry-Cotnam
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No problem Calvin, I'm always open to anyone with a good point or better observation. Inline:
wrote in message said...

===> A GFCI, one which is built to NA standards as requied by law, monitors the difference in current between the hot and the neutral wires. Whenever that current varies too much, I think it's about ten milliamps, the thing trips and turns off the power. IMO, he was given a glib, and wrong, response by that person.

===> It would be fairly rare in any instance, but moreso as you indicated. By the time a spike makes it through the transformer on the pole, and all the inductance in that xfmr, there isn't much of it left for the house wiring, which in turn has a substantial sinking ability due to the things plugged into it. I'd be willing to bet money that no transient was at work in this picture; it just doesn't fit the anecdotal evidence.
Since the original

===> Now, that's a distinct possibility. In fact, I mentioned it in a post a few minutes back that I'd neglected to consider that. If that's the case, then there was an obvious reason for it tripping that anyone worth their salt could have asked about, instead of just that "they do that".

wouldn't make it thru the network into the home wiring and if it was powerful enough to make it thru via arccing or whatever in the xfmr, it's not "noise". There is a lot of "noise" on any of those power lines; it's the design of the lines that protects it from getting into the houses. Else, anyone with a modem could pick off the billing information, all kinds of data that are also flowing up and down those wires. Any signals on those wires cancel themselves and anything left is further reduced by the turns ration in the transformers. There is even a reason for the spacing between power lines, in fact, that comes into play. You can only decode data AT th epower lines termination points. By design, any outside noise is also going to be horizontally applied, and will again be self-damped. It's called longitudinal balance. I used to work on that kind of equipment. It's interesting stuff, actually, since few people know it's there. Electrical and gas consumption billing are two typical applications and anything from lightning to the sun can induce noise into the lines, but due to design, it's reduced to the point where it has no afffect on things.

===> You cannot say that. The gfci tripped, and the reason isn't known. You can not know whether there would be a dangerous fault or not if the GFCI hadn't been there.

===> Like I said, that's possible, but very unlikely to be the problem, given the information available so far in this post. Since we're now going into empirical, anecdotal eveidence, I have a GFCI on my pool pump, too, because I also run the pool lights from it. Then that receptacle goes off to another receptacle/switch, which is used for the yard lighting. It has NEVER tripped before, during, or after a storm. The only time it's ever tripped was when I pressed the test switch, or stuck a resistor between the conduit and the receptacle. There are some valid reasons why some of the larger horsepower motors will cause them to trip, but it's not the noise generated. It's the pase shift caused by the inductance in the motors, especially when they're capacitor starts instead of clutch-started. Either way, the currents in the live/neutral vary sufficiently for the GFCI to detect the current difference, and thus it trips. I recall the last one I bought, a portable, had a reaction time in the micro-second range; that's pretty fast when you consider you're working with a period of what, about 16 mS on 60 Hz? I don't think any of that's relevant to the OP's situation.
However, I DO think your comment about something plugged in at the time of the rain or, whenever the thing opened, is important, since it wasn't specifically noted one way or the other by the OP. That installer sounds either incompetent or sort of, uhh, dishonest and doesn't care since he came up with "they do that".
Cheers,
PopS

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Pop ( snipped-for-privacy@devnull.spamcop.net) said...

So why is so much money spent on surge suppressors? Without getting into the whole-house versus power bar argument, there is electrical noise that can effect electronic equipment in varying degrees.
GFCIs are among the effected, often enough that you should not use them on outlets powering refrigerators.

It does, moreso since the original poster mentioned that there were other loads downstream from the GFCI (the lights).
It would be a pretty rare occurance for a GFCI to trip off due to transients flowing strictly due to the inductive and capacitive load of the power line. I wouldn't say impossible, but think it is fair game to say I have a better chance of winning a lottery.
But with a load of a few lights, there is a somewhat greater possibility that noise might be "seen" by the GFCI as an imbalance.

True. Unfortunately, there seems to be a common attitude of many professionals to give such a terse answer to people outside their profession.
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Calvin Henry-Cotnam
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Calvin Henry-Cotnam wrote:

Good marketing. I dont have any 'intentional' surge surpressors in my house. Not to mention that 99% of surge supressors can absorb a max surge the size of a static shock from a rug...
Devices themselves are more robust these days and small surges wont do much. Especially to electronic equipment.
There is also the question of where the spike originated. Inductive loads like refrigerators and vacuum cleaners, A/C units (especially when faulty) can throw spikes on the line which originate inside the house/transformer. i have still not seen any trippage of my GFCI. But in my old house the voltage drop would induce my battery backup to kick in briefly.

Isint this contrary to your statement about refrigerators which are an inductive load?

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Respectfully,


CL Gilbert
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CL dnoyeB Gilbert ( snipped-for-privacy@ThisOneIsFake.com) said...

No, the "inductive and capacitive load of the power line" that I was speaking of is strictly that: of the power line.
When you apply AC power to a pair of wires with no load at the other end, there will be a small current flowing in that wire, mostly due to the capacitive effect of the wire. The inductive effects generally don't come into play until you try to disconnect those wires and a tiny bit of arcing may be seen.
This effect can be noticed, albeit very tiny, when a branch circuit with nothing on it is disconnected from the power source. I have seen this effect quite dramatically when a substation was being disconnected from its source -- after the load is shut off, then the disconnects are opened at the top of the substation, the power company then had a guy in a cherry picker disconnect the wires at the pole. With about 50' of wires connected to nothing at the far end, there is quite a visible and audible spark when those wires are disconnected from the supply (I don't recall the voltage, but it was at least 4600 and not likely over 16,000).
Getting back to my point, with only the effects of a non-loaded cable on a GFCI, I do not believe that it is likely that any transients can trip the GFCI. With a load on the cable downstream from the GFCI (lights or a refrigerator for instance), the odds improve significanty. Not that you will see it occuring on a weekly basis, but going from "practically never" to, say, 1 in 10000, is a significant increase.
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said...

electrical storms are a major source of TV repairs and a specific profit center for our family TV repair business. I have everything in the house protected by surge suppressors and even at that a nearby lightning strike was strong enough to smoke the surge protector on my stereo power amplifier and the amplifier itself, although the plasma TV (on a different supressor) escaped unharmed. The manufacturer of the surge supressor pai me for a new power amplifier.

These aren't small surges, and electronics are, IMHO, getting MORE sensitive and more expensive, not less.
Neither of my two comments are related to GFCIs, but to the earlier poster's overall comments on power surges.

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snipped=========================> >> So why is so much money spent on surge suppressors?

IEEE says if you want surge protection you must protect 2 of the three zones. Since the utility won't allow you to put one on their lines that will protect you. Your stuck with one at the service and one at the point of use. Doing your cable and telco is also a good idea.
I have seen lightning strikes that were 1/4 mile away fry every electronic ballast in a building.
The CEBMA curve is what the manufactures use to decribe tolerance to voltage spikes. No matter what you install nothing is bullet proof. Since most surge arrestors use MOV's to do the dirty work. I change them every other monsoon season. Cheaper than a new plasma tv and dealing with the manufactures for me.
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Calvin Henry-Cotnam wrote:

The 2005 NEC requires GFCIs on 15 & 20 amp outlets in "commercial kitchens". This appears to include refrigerators. (Electricians in a code refresher class thought it was a dumb idea.)
Bud--
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I agree with the guy that they do seem to do that. If you had a licensed electrician put the thing in I would not sweat it. If though the feed somehow could have gotten wet, that's what gfci is intended to react to, which may indicate some sort of leak somewhere ? Did they run the outdoor wire thru a conduit and all that jazz ?
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Thanks, to you and Edwin. The wire is running through conduit. Shouldn't it be weatherproof against heavy (but normal, expected) rain?
- Andrew

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have to worry. A nearby lightning strike (either cloud-to-cloud or cloud-to-ground) can sometimes also trip a GFCI, thru an induced current -- an infrequent (emphasize "infrequent") GFCI trip is not necessarily a problem, especially if you can associate the occurence with a severe thunderstorm. Regards --
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