# GFCI trips at the same time



## ATJaguarX (Oct 16, 2011)

I have a GFCI in my basement that my computer equipment is connected to. I have a number of different pieces of equipment plugged in. Occasionally, once a week, I would get up in the morning and all my computer equipment would be off and I noticed that the GFCI was tripped. To help cleanup the power coming and going to the equipment, I purchased a CyberPower 510 watt UPS. Also, being a software developer, I decided to write an application that writes to a log file every minute to help determine when the GFCI would trip.

After letting the logging application run for a few weeks and monitoring when the GFCI was tripping, I noticed that it would trip every couple days between the hours of 5:15am and 5:45am.

I decided to start removing pieces of the puzzle. First, I removed the computer as I have no idea what its doing at times of the night. After 1 week, the GFCI tripped again. The only thing I have left on the UPS is the router and a network switch.

This has been happening for 6 months now... every few days, between the hours of 5:15am and 5:45pm (NEVER any other time... not once in 6 months) the GFCI trips. I've replaced the GFCI with a new one and that didn't help.

Any thoughts?


----------



## kbsparky (Sep 11, 2008)

Your surge protector is shunting out a power surge that occurs at roughly the same time each day. By doing so, the GFCI senses the mini-fault, and interprets it as a ground-fault condition, and then trips out.

Either remove the surge power strip, or install another non-GFCI protected outlet for your equipment. If you have a finished room, GFCI protection is not required.


----------



## gregzoll (Dec 25, 2006)

That is one thing I do not understand about people KB. They want to run mission critical devices in their home (ie servers & networking equipment), but hook it up to gfci protection. I know that in our area, the power peaks to almost 250vac anywhere between Midnight & five a.m. Low's I have seen around 220vac at the lowest during the same hours.


----------



## Billy_Bob (Sep 11, 2008)

GFCI's are intended to protect people using handheld electrical items from electrocution.

For example outside someone may plug in an extension cord, then handle it, and someone before cut through it with the hedge trimmers leaving a bare wire. Then as you handle the cord, you touch that bare wire... But the GFCI shuts off power instantly and you are safe.

It detects a fault to ground. Or electricity going through your body.

Sort of like a "bank teller". The same amount of electricity going out one wire must also come back through the other wire. If any electricity is "missing" (going through your body to ground), then power is instantly shut off.

With that said, I see no reason to place computer equipment on a GFCI when a regular outlet would be allowed in that area. Anything I might touch with my computer equipment is plastic.

However *very* good idea for outlets in bathroom, kitchen, garage, outside, basement, laundry, etc. (wet areas) where handheld gizmos might be plugged in. Also for garage door openers. There have been cases where a garage door opener had a malfunction and energized the metal garage door. Then a small kid touched the metal garage door.


----------



## gregzoll (Dec 25, 2006)

The thing is Billy Bob, you do not want to use gfci protection on networking, alarm systems, computer, or mission critical devices. Even those devices that work to protect a person, due to a medical condition, you do not want it on gfci protected circuits.


----------



## ATJaguarX (Oct 16, 2011)

Billy_Bob said:


> With that said, I see no reason to place computer equipment on a GFCI when a *regular outlet would be allowed in that area. *
> 
> However *very* good idea for outlets in bathroom, kitchen, garage, outside,* basement*, laundry, etc. (wet areas) where handheld gizmos might be plugged in.


That's the problem... it is in my basement and it is code in my city to have GFCI outlets in the basement.


----------



## ATJaguarX (Oct 16, 2011)

gregzoll said:


> That is one thing I do not understand about people KB. They want to run mission critical devices in their home (ie servers & networking equipment), but hook it up to gfci protection.


I wouldn't say it is mission critical devices... this is just my home with a home network. I'm not running a business here. It is very common practice for people to put their networking equipment in their basements (actually, it's an option with my builder). It is also code for me to have a GFCI in my basement.


----------



## ATJaguarX (Oct 16, 2011)

kbsparky said:


> Your surge protector is shunting out a power surge that occurs at roughly the same time each day. By doing so, the GFCI senses the mini-fault, and interprets it as a ground-fault condition, and then trips out.
> 
> Either remove the surge power strip, or install another non-GFCI protected outlet for your equipment. If you have a finished room, GFCI protection is not required.


I'm not quite following here so please don't slam me for it. What could be causing the power surge? Is it my equipment causing the surge? What would be causing the power surge at roughly the same time?

The "surge power strip" is more then your basic power strip. It is a UPS that is supposed to provide "automatic voltage regulation (AVR) topology delivers clean and consistent AC power".

http://www.cyberpowersystems.com/products/ups-systems/adaptive-sinewave-series/CP850PFCLCD.html

If it was as easy as removing my GFCI, I would, but it's there because of code.


----------



## gregzoll (Dec 25, 2006)

It is code for me to have one also, only due to the fact that I updated the wiring in the house in 2003. Before it was not required, due to the original wiring was from 1937. I stop when it comes to hooking up networking equipment or servers to them. My network switch and RG from ATT is hooked up to a regular outlet, no gfci in the loop. Never have had any problems ever. I would not doubt that the Cyber power is suspect. Try hooking the equipment up directly without the UPS and see if the gfci trips. If it does trip, try another gfci.


----------



## kbsparky (Sep 11, 2008)

It's not your equipment that is causing the surge. It could be anything within several miles that starts up at about the same time each day.

The surge is coming in from the outside, on the same power lines.

Therein lies the problem: The surge shunting capability of your UPS system is fooling the GFCI to trip out.


----------



## ATJaguarX (Oct 16, 2011)

gregzoll said:


> It is code for me to have one also, but I stop when it comes to hooking up networking equipment or servers to them. My network switch and RG from ATT is hooked up to a regular outlet, no gfci in the loop. Never have had any problems ever. I would not doubt that the Cyber power is suspect. Try hooking the equipment up directly without the UPS and see if the gfci trips. If it does trip, try another gfci.


From what i've read on here, it sounds like the UPS is suspect, but I don't blame the UPS directly. I've tried a number of other scenarios, regular surge protectors etc... but never have I hooked up the equipment directly. The idea scares me due to the reason I purchased the UPS, we often have power outages for a few seconds here and there. The last time I had the equipment not hooked up to a UPS/surge protector, I blew a network switch.


----------



## ATJaguarX (Oct 16, 2011)

Billy_Bob said:


> However *very* good idea for outlets in bathroom, kitchen, garage, outside, basement, laundry, etc. (wet areas) where handheld gizmos might be plugged in.


Funny thing, it's code to have a GFCI in my basement, yet my sump pump is not hooked up to one. :confused1:


----------



## gregzoll (Dec 25, 2006)

ATJaguarX said:


> Funny thing, it's code to have a GFCI in my basement, yet my sump pump is not hooked up to one. :confused1:


That would be because it most likely would trip the gfci that was on that circuit, or it is downstream of another gfci. How old is this house, and when was the electric last updated?


----------



## gregzoll (Dec 25, 2006)

ATJaguarX said:


> From what i've read on here, it sounds like the UPS is suspect, but I don't blame the UPS directly. I've tried a number of other scenarios, regular surge protectors etc... but never have I hooked up the equipment directly. The idea scares me due to the reason I purchased the UPS, we often have power outages for a few seconds here and there. The last time I had the equipment not hooked up to a UPS/surge protector, I blew a network switch.


It has already been explained that it has nothing to do with the UPS, but the fact that something in your area causes a large surge? Any industry in your area, nursing home, funeral home, etc? How old is the neighborhood?


----------



## ATJaguarX (Oct 16, 2011)

gregzoll said:


> It has already been explained that it has nothing to do with the UPS, but the fact that something in your area causes a large surge? Any industry in your area, nursing home, funeral home, etc? How old is the neighborhood?


I'm confused as both yourself and kbsparky mentioned that that the shunting capability of the UPS system is fooling the GFCI to trip out. I understand that my equipment is not causing the surge, but something outside my house.

I am relatively close (a few blocks away) to a small industrial park. The neighborhood is approximately 6 years old and my house is 4 years old. I've had my computer equipment on the same outlet for 4 years and only this year has it been a problem.

My sump pump is on its own dedicated breaker. From my understanding, equipment, such as this, on its own dedicated circuit, with a single outlet, is not required to have a GFCI.


----------



## kbsparky (Sep 11, 2008)

Any one of those nearby businesses could have installed something recently that gets started up first thing in the morning. The inrush of power from the utility to get that beastie started and running can cause your surge unit to shunt out and trip your GFCI. Not all the time, but enough times to cause nuisance tripping.

IF you could install a surge unit ahead of your GFCI (like a whole house unit), that might minimize your nuisance tripping. Or, you could "cheat" and plug in a cube tap at your sump pump outlet, and run your computer stuf from there.... :whistling2:


----------



## ATJaguarX (Oct 16, 2011)

kbsparky said:


> Any one of those nearby businesses could have installed something recently that gets started up first thing in the morning. The inrush of power from the utility to get that beastie started and running can cause your surge unit to shunt out and trip your GFCI. Not all the time, but enough times to cause nuisance tripping.


That sounds about right...



kbsparky said:


> IF you could install a surge unit ahead of your GFCI (like a whole house unit), that might minimize your nuisance tripping. Or, you could "cheat" and plug in a cube tap at your sump pump outlet, and run your computer stuf from there.... :whistling2:


This GFCI is the only outlet on this breaker. Couldn't I do the same, and put a single outlet in? If its ok for the sump pump, shouldn't it be ok for my computer equipment?


----------



## westom (Aug 23, 2009)

ATJaguarX said:


> I'm confused as both yourself and kbsparky mentioned that that the shunting capability of the UPS system is fooling the GFCI to trip out.


 Surges are rare events. Overly frequent if one exists annually. Even noise will not trip a GFCI. GFCI trips due to something unacceptable in hardware. Something measured at all times. That is just below a GFCI's trip threshold. GFCI does not trip immediately because the failure is constantly below and intermittently exceeds 5 milliamps.

 GFCI trips because a current going into those appliances on a black (hot) wire is milliamps different from the current coming back on the white wire. That milliamp leakage would exist constantly. Can be identified by tools that measure electricity; even sold in Kmart. Because that leakage exists constantly.

 All appliances leak some current. Microamps of current is acceptable. Even one milliamp of leakage means the appliance is defective. But not large enough to constantly trip a GFCI.

 How can leakage exceed 5 milliamps? Two defective appliances might do it. If swapping or disconnecting to find the failure. then both defective appliances, alone, would not trip the GFCI. Swapping and disconnecting would never identify defects. Would only cause confusion. Confusion is what you have due to answers not defined by numbers.

 Your tests imply leakage inside a defective UPS. A constant failure that only gets a little bit higher intermittently. But again, that conclusion is a classic example of wild speculation. Because it is not defined by something definitive - numbers. Subjective conclusions are why junk science exists. And why simple problems cause so much confusion.

 Your GFCI is reporting a failure that exists 100% of the time. But only exceeds the 5 milliamp threshold intermittently. Speculated 'dirty' power and other anomalies (ie voltage variations) are irrelevant and would not cause GFCI tripping.

 So let's make a tool that might make finding the one or multiple defective appliances easier. Buy a plug from Lowes, et al. And two 100 Kohm (1/4 or 1/2 watt) resistors from Radio Shack (part number 271-1131). Connect two (or three) 100 Kohm resistors from the plug's hot prong to its safety ground prong. When that plug is connected to the GFCI circuit, then leakage will be about 2 (or 3) milliamps. Not enough to trip a GFCI. But maybe enough to trip that GFCI when a defective appliance is also powered by that circuit.

 Ignore 'dirty' power or low voltage. Ignore speculation that does not say what a GFCI does. Above paragraphs define what causes a GFCI trip, why constantly defective appliances can intermittently trip a GFCI, and how any layman can more easily identify a defective appliance. The last paragraph demonstrates solving a problem by using hard facts generated with numbers. No speculation.


----------



## gregzoll (Dec 25, 2006)

ATJaguarX said:


> I'm confused as both yourself and kbsparky mentioned that that the shunting capability of the UPS system is fooling the GFCI to trip out. I understand that my equipment is not causing the surge, but something outside my house.
> 
> I am relatively close (a few blocks away) to a small industrial park. The neighborhood is approximately 6 years old and my house is 4 years old. I've had my computer equipment on the same outlet for 4 years and only this year has it been a problem.


See, you answered your question as to why your gfci is tripping.


----------



## gregzoll (Dec 25, 2006)

Kb, in one of the neighborhoods close by to us, there is a machine shop that does work for Caterpillar. I am sure that with the type of machinery they have, would be enough to cause havoc in the houses behind the shop, and the others on the same section of the grid. I am sure if the OP investigated, they would find out that there is the same type of shop, or even a recycler in that park, starting up their equipment first thing in the morning would be enough to cause havoc.

The sad thing is, there are not many electric grids laid out properly to not cause problems with the neighbors.


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> Your tests imply leakage inside a defective UPS. A constant failure that only gets a little bit higher intermittently.


I don't think the UPS is defective as I had the same exact problem with the 2 previous pieces of "surge protection" equipment. The problems started this year, never had problems with the same equipment for the prior 5 years.



westom said:


> Your GFCI is reporting a failure that exists 100% of the time. But only exceeds the 5 milliamp threshold intermittently.


Why would "intermittently" be exactly between 5:15am and 5:45am and NO OTHER TIME?


----------



## gregzoll (Dec 25, 2006)

ATJaguarX said:


> I don't think the UPS is defective as I had the same exact problem with the 2 previous pieces of "surge protection" equipment. The problems started this year, never had problems with the same equipment for the prior 5 years.
> 
> 
> Why would "intermittently" be exactly between 5:15am and 5:45am and NO OTHER TIME?


Would suggest going to the industrial park and finding out what kind of businesses are there. Large equipment when it starts up, especially those that use large motors can cause drops on the line, and if not properly installed, can cause line surges, due to possible back feeding of power on a opposite phase.

http://www.ehow.com/list_7285798_causes-home-electrical-surges_.html
http://search.yahoo.com/search;_ylt...al+lines&fr=att-portal&toggle=1&cop=&ei=UTF-8

Would suggest getting one of these http://www.lowes.com/pd_30639-82364...ouse+surge&N=0&langId=-1&storeId=10151&rpp=48 or these http://menards.com/main/electrical/...s/surge-supp-whole-house/p-1464337-c-6412.htm


----------



## westom (Aug 23, 2009)

ATJaguarX said:


> Why would "intermittently" be exactly between 5:15am and 5:45am and NO OTHER TIME?


 System noise can cause leakage to vary just enough above the threshold. That noise involves something beyond this technical level. 

 The point remains. Avoid subjective conclusions. Ignore observations that are not tempered by fundamental facts - such as how a GFCI works.

 I know some reasons why the GFCI might trip at a certain time. And those reasons are not relevant to a fundamental fact. Some appliance (or house wire) is leaking current - a defect exists. Find that defect. Noise does not cause milliamps of leakage.

 Do the test. Discover what actually exists. Does not matter how many other appliances do and do not cause a failure. Only fact that matters is what THAT UPS or other appliance is doing. All that other stuff (ie what it was doing 5 years ago, events at 5:30, etc) is only confusing you. Means nothing if you cannot attach it to how a GFCI works.

 Why did this problem just start this year? A bypass capacitor inside one of the appliances has failed. Do not assume that is THE answer. That is only one of maybe 50 speculated reasons for something changed. We don't care what it was doing 5 years ago. Relevant is only what exists now. That means numbers.

 That layman test (resistors and AC plug) is example of an experiment based in numbers and a hypothesis. A hypothesis based in how a GFCI really works.


----------



## Billy_Bob (Sep 11, 2008)

ATJaguarX said:


> Funny thing, it's code to have a GFCI in my basement, yet my sump pump is not hooked up to one. :confused1:


Oregon has modifications to the electrical code. Last time I checked, sump pumps and refrigerators/freezers were an exception to the GFCI rule. (Not required for those.)

GFCI's are required for these in other states. (Check your local electrical inspector's office for NEC rule ammendments.)


----------



## Billy_Bob (Sep 11, 2008)

Here are those Oregon modifications to the NEC...
http://www.cbs.state.or.us/external/bcd/programs/electrical/2011_oesc/Table_1_E-Effective_040111.pdf


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> The point remains. Avoid subjective conclusions. Ignore observations that are not tempered by fundamental facts


Are you implying that I should not listen to other's responses regarding the nearby industrial park?




westom said:


> Why did this problem just start this year? A bypass capacitor inside one of the appliances has failed.


Actually, now that I think about it... since I started experiencing this problem, I have replaced *ALL *the equipment. So if it is an issue with the equipment, it was an issue with the old equipment *AND *the new equipment.

So confused... :confused1:


----------



## westom (Aug 23, 2009)

ATJaguarX said:


> Are you implying that I should not listen to other's responses regarding the nearby industrial park?


 Tell me why any noise causes GFCIs to trip. If the industrial park is tripping your GFCIs, then how do they keep their equipment working? 

 If noise causes a GFCI to trip, then the post also says why - and with numbers. Learning these concepts is why we solve problems.

 Cheaper to always have professionals do it. We solve problems, first and foremost, to learn how to solve problems. Solutions that do not say why and that do not include numbers are best called speculation.

 Also why we learn from history. Same logic that says the industrial park causes GFCI tripping also proved Saddam had WMDs. We who know why numbers are always important also saw through that myth.

 Why does a GFCI trip? It was defined. And with numbers. Also provided is how to obtain useful facts for your unique situation.

 On CSI, they say "Follow the evidence". Posted was how one follows that evidence. Not on speculation from what existed five years ago or from noise only rumored to exist from some nearby factory. A GFCI trips due to a greater than 5 milliamp difference in an up to 20,000 milliamps current. Get those resistors and plug. Do the experiment because the hypothesis is based in science (not in speculation). Then one who really knows this stuff has a fact to provide a useful answer. Then we 'follow the evidence' provided by that experiment.

 Not yet learned is what 'follow the evidence' means. Dispose of any recommendation that comes without numbers. Show me why noise causes a GFCI trip. No fact says external noise causes a GFCI trip. If the reason why is not provided, then the claim is only wild speculation. Noise does not cause tripping.

 Ignore subjective conclusions: anything not supported by numbers, well proven science, and how a GFCI works. Do the experiment. Then others who have been doing this stuff before GFCIs existed can provide hard facts – with reasons why and numbers.


----------



## a7ecorsair (Jun 1, 2010)

ATJaguarX said:


> The only thing I have left on the UPS is the router and a network switch.


This thread is getting quite long:yes:
In this posting you said the only thing on the UPS is the router and switch. Move these two devices to some other circuit using an extension cord or what ever but leave the UPS on the GFCI. This way you will have a load on the GFCI and also, originally, the UPS wasn't in the game.
Now, is the UPS the only thing on the GFCI? You said you replaced the GFCI so the question is, are there any wires connected to the load side of the GFCI?


----------



## Billy_Bob (Sep 11, 2008)

As to electrical disturbances from elsewhere... Large computer rooms have large UPS's which also have logs of "power line events".

I saw one of these logs and there was a power line event about once an hour. This can be frequency out of whack, voltage surges, voltage drops, etc.

So quite common for the electricity provided by the electric company to have "weirdness" many times a day.

Some of these events are voltage surges, maybe just for a split second, but that is when the voltage goes above normal...

Then the way surge protectors work is they have a "varistor" connected from each electrical line (hot and neutral) to ground. These varistors "turn on" after the voltage reaches a certain point (voltage surge)...

And if you have a GFCI prior to that surge protector, then it will notice some electricity going elsewhere than hot and neutral (ground), thus the GFCI trips.

Surge protector diagram - Varistor aka "MOV"...
http://www.seekic.com/uploadfile/ic-circuit/200971722818810.gif

http://en.wikipedia.org/wiki/Varistor


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> Do the experiment.


I'd love to do the experiment... if you could provide a little more details would be helpful.

Thanks!


----------



## ATJaguarX (Oct 16, 2011)

a7ecorsair said:


> In this posting you said the only thing on the UPS is the router and switch. Move these two devices to some other circuit using an extension cord or what ever but leave the UPS on the GFCI. This way you will have a load on the GFCI and also, originally, the UPS wasn't in the game.


The router, switch and UPS are all approximately 2 months old. 2 months ago, a thunderstorm rolled through and blew my switch. At that point, I purchased the UPS and switch. Shortly after that, I updated my internet and received a new router. I do have other equipment connected to the UPS (VOIP box, Printer, Computer), but all are powered off.



a7ecorsair said:


> Now, is the UPS the only thing on the GFCI? You said you replaced the GFCI so the question is, are there any wires connected to the load side of the GFCI?


Nothing on the load side.


----------



## Billy_Bob (Sep 11, 2008)

ATJaguarX said:


> Why would "intermittently" be exactly between 5:15am and 5:45am and NO OTHER TIME?


Note: The UPS probably has built in surge protection...

As to voltage surges happening at a certain time, businesses and industrial electric customers get reduced electric rates for using electricity during "off peak" hours. So they have things on timers to turn them on/off during certain hours. Peak time in my area starts at 6:00 am.

Also it could be many customers with things set to turn on or off at the same time. Or even 100,000 people turning on their coffee makers at the same time!

FYI - Here is a GFCI diagram. The center ring detects electricity flowing inside it. Hot and neutral oppose each other, so no electric flow detected normally. But if some electricity goes to ground, or test button pressed, then an "imbalance" occurs and the GFCI is tripped.

http://www.diychatroom.com/attachme...-have-4-lead-4-load-holes-gfci-schematic1.jpg


----------



## frenchelectrican (Apr 12, 2006)

ATJaguarX said:


> Why would "intermittently" be exactly between 5:15am and 5:45am and NO OTHER TIME?


As other mention some of med / large commercal / industrail customers have large equiment that can wreck hovac on the POCO sytem I know from my expernice in Wisconsin we have very large recycle plant { they have huge shreadder } every time before they fire up big 7500 HP motour they have to call the POCO to boost the voltage a bit to compersied the starting surge so that one possiblty you may have simauir situation.

Otherwise the POCO capaitour bank switching in or out that can cause surge as well I have see it often when they do switch out after 1600 { 4 PM } and switch back at 0600 so that two spot I know it will show up in Wisconsin but in France most common surge time will be 1600 or 1700 { UK are famous for that } 

Merci,
Marc


----------



## ATJaguarX (Oct 16, 2011)

I can't believe I forgot to mention this. Around the same time I started noticing my GFCI was tripping in the basement, my GFCI started tripping in my garage. I had a Surge Protector in my garage hooked up to the GFCI with a dust buster plugged into the surge protector. I unplugged my surge protector in my garage and I don't recall having a single trip since then.

Also, around the same time I started noticing the tripped GFCIs, Nicor built a facility about 2 blocks from my house. I wonder if they have something going on around 5am every day.

I'm starting to think that all 3 are somehow related.


----------



## ATJaguarX (Oct 16, 2011)

Ok, so let's *assume* that its a near by facility that is wreaking havoc in my house. Since a GFCI outlet is required by code, what are my options? I have a feeling that I can't just walk up to the Nicor building and say "hey, you're tripping my GFCIs in my house... knock it off.".


----------



## frenchelectrican (Apr 12, 2006)

ATJaguarX said:


> Ok, so let's *assume* that its a near by facility that is wreaking havoc in my house. Since a GFCI outlet is required by code, what are my options? I have a feeling that I can't just walk up to the Nicor building and say "hey, you're tripping my GFCIs in my house... knock it off.".


Not excatally that kind of approch but if you talk to the POCO ( Power Companie ) they can able help you with the surging situation you have going on and they can put their own recording device and read it for next couple days and they can able determed to slove the issue much as possible.

Merci,
Marc


----------



## mpoulton (Jul 23, 2009)

Three things:
1: I think you should try plugging your UPS into a non-GFCI receptacle for a few days. Use an extension cord if you need to. Check the log files for the UPS around that time of day, and look for any events. If our suspicions about the line voltage spiking excessively high and triggering the surge suppression are correct, then the UPS will probably transfer to battery power and log an event when that happens. You will not have seen this in the logs yet, because the GFCI has been tripping and causing an outage. If you can confirm that there is actually a recurring power quality anomaly at that time every day, then we know we've identified the problem and can work on a solution. If your UPS logs the actual line voltage, that would be really cool to know. I had a cheap APC unit that did, so maybe yours does too.

2: If your UPS logs can verify a recurring power quality anomaly at that time in the mornings, then you probably should contact your power company. It takes a pretty darn high voltage (330V) to trigger the MOV's in most surge suppressors, and it's very hard on them. They are not intended to actually absorb surges on a regular basis. I would say that whole-house surge suppression would be the likely solution to your problem, but if it's going to be triggering every morning it won't last very long. Besides, the power company should pay for it anyway if they're not delivering clean power.

3: Westom: All of your statements about the function of GFCIs and power surges are correct. However, you're forgetting one very important thing and it's throwing you off track (and incorrectly making you think the rest of us are wrong): Surge suppression works by shunting current to ground. MOV's are devices that begin conducting when the voltage across them exceeds a certain value. They are connected between the hot, neutral, and ground conductors. If the voltage between any conductor and ground exceeds the MOV's design voltage, it conducts and clamps the line voltage, preventing damage to the downstream equipment. Of course, this will trip any GFCI since the clamped surge current returns on the grounding conductor. This is why we all believe the equipment is not defective, it's just two different protective systems doing their jobs. The MOV's clamp the surge, shunting current to ground. The GFCI detects the missing current and trips. This is the only explanation that accounts for the regularity of the events. The interaction of surge suppression and GFCI's is also a well known problem.


----------



## westom (Aug 23, 2009)

ATJaguarX said:


> Ok, so let's assume that its a near by facility that is wreaking havoc in my house.


In a previous post, I noted at least 50 reasons for only one of many possible failures. When hard facts do not exist, another 1000 possibilities can create a "War and Peace" novel. You are rationalizing a simple problem to death by inventing what cannot happen, what is not relevant, and what would be unlikely. Do the experiment. 

Buy a plug from Lowes. And two 100 Kohm (1/4 or 1/2 watt) resistors from Radio Shack (part number 271-1131). Connect two (or three) 100 Kohm resistors from the plug's hot prong to its safety ground prong. When that plug is connected to the GFCI circuit, then leakage will be about 2 (or 3) milliamps. Not enough to trip a GFCI. But maybe enough to trip that GFCI when a defective appliance (or defective wire in the wall) is also powered by that circuit.

We could write another novel just from the many trivial and nearly impossible reasons for a GFCI trip. How many more chapters do you want? Do you really want to read them all? Do the experiment to eliminate or identify over 99% of the reasons for that GFCI trip. Stop trying to discover all 1000 reasons including the 100 that are actually possible. Nothing useful can be concluded when facts are subjective.

Do the experiment. Eliminate chapters of wild speculation by having numbers. Only then will relevant details emerge.


----------



## westom (Aug 23, 2009)

mpoulton said:


> MOV's are devices that begin conducting when the voltage across them exceeds a certain value. ... The MOV's clamp the surge, shunting current to ground. The GFCI detects the missing current and trips.


 Surges exceeding 330 volts occur typically once every seven years. Are microsecond events. To trip a GFCI, that one surge must be tens of milliseconds. A millisecond surge means plenty of damaged appliances including GFCIs. Please stop inventing possibilities that can exist only by ignoring important numbers such as microseconds verses milliseconds. Your reasoning is correct ONLY if we ignore those numbers.

Do the experiment now to have facts not invented by subjective reasoning and wild speculation.


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> . Not enough to trip a GFCI. But maybe enough to trip that GFCI when a defective appliance (or defective wire in the wall) is also powered by that circuit.


There are no downstream outlets powered by this GFCI (thus no other appliances). The GFCI is mounted directly to the breaker box, is the only outlet on the breaker and the wire feeding the outlet is maybe 12 inches long. I'm not sure it can be any other appliances or the wiring.


----------



## kbsparky (Sep 11, 2008)

It seems that the only times your GFCI are tripping, is when you have a surge protector plugged into it, right?

So get an expensive whole house surge protection unit, and install it at your panel! Ahead of the GFCI units.

That should clear up the problem. :whistling2:


----------



## ATJaguarX (Oct 16, 2011)

My UPS has a sensitivity setting. It is defined as:



> It is to control the sensitivity of the UPS to switch to Battery Mode by selecting UPS shutdown voltage range. The higher the sensitivity, the easier the UPS will switch to Battery Mode.



My options are as follows:


Low Sensitivity (78-142Vac) - (Not recommended for computer loads).
Medium Sensitivity (88-139Vac)
High Sensitivity (88-136Vac)

And yes, it does have surge protection built in.

Below is a brief description:



> The CP850PFCLCD/CP1000PFCLCD provides complete power protection from utility power that is not always consistent. The CP850PFCLCD/CP1000PFCLCD features 1030 Joules of surge protection. Both units provide long lasting battery backup during power outages with maintenance free batteries.
> 
> AUTOMATIC VOLTAGE REGULATOR
> The CP850PFCLCD/CP1000PFCLCD stabilizes inconsistent utility power voltage to nominal levels that are safe for equipment. Inconsistent incoming utility power may be damaging to important data files and hardware, but with Automatic Voltage Regulation (AVR), damaging voltage levels are corrected to safe levels. AVR automatically increases low utility power and decreases high utility power to a consistent and safe 110/120 volts. If incoming utility voltage drops below 90 volts, or exceeds 140 volts the units automatically switch to battery back-up power.



Attached is a diagram of the system.


----------



## Billy_Bob (Sep 11, 2008)

ATJaguarX said:


> Ok, so let's *assume* that its a near by facility that is wreaking havoc in my house. Since a GFCI outlet is required by code, what are my options? I have a feeling that I can't just walk up to the Nicor building and say "hey, you're tripping my GFCIs in my house... knock it off.".


 
At the above link and the Oregon exceptions to the NEC it says...

[Exception No. 1 to (2): A single receptacle for each appliance within a dedicated space that, in normal use, is not easily moved from one place to another, that is cord-and-plug connected, and the receptacle is labeled as “not GFCI protected.”]

Perhaps your computer could fit into that exception? It is mainly intended for something like a refrigerator or freezer. Or you could ask that they re-word the exception to also include a computer.

Ask your local electrical inspector.


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> Buy a plug from Lowes. And two 100 Kohm (1/4 or 1/2 watt) resistors from Radio Shack (part number 271-1131). Connect two (or three) 100 Kohm resistors from the plug's hot prong to its safety ground prong. When that plug is connected to the GFCI circuit, then leakage will be about 2 (or 3) milliamps. Not enough to trip a GFCI. But maybe enough to trip that GFCI when a defective appliance (or defective wire in the wall) is also powered by that circuit.


How do I measure the leakage? So, what does this test tell me? Does this only test the GFCI? You mention 50 other ways to find the culprit, but the culprit may be one of the devices. How do I test the devices?


----------



## mpoulton (Jul 23, 2009)

westom said:


> Surges exceeding 330 volts occur typically once every seven years. Are microsecond events. To trip a GFCI, that one surge must be tens of milliseconds. A millisecond surge means plenty of damaged appliances including GFCIs. Please stop inventing possibilities that can exist only by ignoring important numbers such as microseconds verses milliseconds. Your reasoning is correct ONLY if we ignore those numbers.
> 
> Do the experiment now to have facts not invented by subjective reasoning and wild speculation.


Well, since you're the one proffering these "numbers" to refute our proposed explanation, the onus is on you to provide a reliable source for your data. Post some links to reliable sources. Until then, I'm going to operate on some different assumptions: surges sufficient to trigger the MOV's may happen regularly if there are serious utility power quality problems; If the surge is utility-created, the duration will be more like tens of milliseconds (a full 60Hz cycle or two) than microseconds (lightning induced); GFCI's are inverse-time devices and can trip very quickly if the detected fault current is well above 5mA.


----------



## ATJaguarX (Oct 16, 2011)

kbsparky said:


> It seems that the only times your GFCI are tripping, is when you have a surge protector plugged into it, right?
> 
> So get an expensive whole house surge protection unit, and install it at your panel! Ahead of the GFCI units.
> 
> That should clear up the problem. :whistling2:


I'm wondering if I should be responsible for this. Shouldn't the POCO be responsible for providing clean energy to my house?


----------



## ATJaguarX (Oct 16, 2011)

I created an "electric trouble ticket" with the POCO... let's see what happens.

:thumbsup:


----------



## gregzoll (Dec 25, 2006)

ATJaguarX said:


> I'm wondering if I should be responsible for this. Shouldn't the POCO be responsible for providing clean energy to my house?


No, the POCO is responsible for making sure that your lights are on, and that the power fluctuations are no greater than +/- 5 to 7 percent.


----------



## westom (Aug 23, 2009)

ATJaguarX said:


> How do I measure the leakage? So, what does this test tell me?


 If you knew what a GFCI does and how it works, then those answers were obvious. You were already told what a GFCI does and how to measure leakage. Buy an AC plug and some 100K resistors. Do the test. A next post says what you have, what the test reported, what is good or bad, and why that test says so with numbers.

 Or just assume a factory with no GFCI failures is causing your GFCI to trip. Your choice. The engineering behind that test was already defined.

 Also provided may be information that says why other recommendations from kbsparky and gregzoll are useful. Those recommendations may have averted damage that is now causing GFCI tripping. Everything is only speculation until that test is performed and damage is identified. To eliminate maybe 100 possible suspects. Your choice. Identify the problem now. Or just keep speculating.


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> If you knew what a GFCI does and how it works, then those answers were obvious. You were already told what a GFCI does and how to measure leakage. Buy an AC plug and some 100K resistors. Do the test. A next post says what you have, what the test reported, what is good or bad, and why that test says so with numbers.


You're missing the point to my question. I'm not an electrician, otherwise I wouldn't be on this forum asking questions. Ok, so I buy an AC plug and some 100k resistors. I plug this into the GFCI. I'm asking what should I expect once I perform your test... and please don't say "an answer". Am I expecting the resistors to blow up into showers of blue and gold? Am I expecting the resistors to speak to me and say "your gfci is good"? I understand the "Cause"... what is the "Effect"?


----------



## ATJaguarX (Oct 16, 2011)

gregzoll said:


> No, the POCO is responsible for making sure that your lights are on, and that the power fluctuations are no greater than +/- 5 to 7 percent.


Wouldn't a fluctuation of +/- 5 to 7 percent be enough for my surge protector to shunt the surge and trip my GFCI?


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> If you knew what a GFCI does and how it works, then those answers were obvious.


I understand how a GFCI works... it trips because a current going in on a black (hot) wire is milliamps different from the current coming back on a white (neutral) wire.

Are you saying that a surge protector, when provided a surge, can not trip a GFCI? Please, a simple "yes" or "no" will suffice.




westom said:


> All that other stuff (ie what it was doing 5 years ago, *events at 5:30*, etc) is only confusing you. Means nothing if you cannot attach it to how a GFCI works.


I don't see how the 5:30am FACT can be ignored.


----------



## gregzoll (Dec 25, 2006)

Depends on how sensitive the surge protector is. That is why you do not use surge protectors with gfci outlets. It is a either or, not both. Again, if it is a/v or computer equipment, get it off of the gfci and use just the surge protector.


----------



## westom (Aug 23, 2009)

ATJaguarX said:


> I don't see how the 5:30am FACT can be ignored.


 How would you know? Purpose of an AC power plug and two resistors is not even understood. An experiment best given to a junior high school student because it is that trivial. Amusing is how much you will do to avoid labor.

Defined by others. A voltage less than 330 volts is completely ignored by any protector. What is +/- 5 to 7 percent change on 120 volts? I leave you to do the multiplication. If you ignore numbers, then you cannot possibly understand why 5:30 is also irrelevant. At most an anomaly created only because, well, that was also explained earlier.

Either a surge is ignored by a GFCI. Or a GFCI is destroyed by a larger surge. Tripping is not on a list of anomalies created by a surge. And was answered but again by numbers (ie microseconds and milliseconds).

If you want an solution, then do that experiment; so simple that a 14 years old could do it. Or just waste the POCO's time as others have also suggested.


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> Purpose of an AC power plug and two resistors is not even understood. An experiment best given to a junior high school student because it is that trivial.


I've never heard of a junior high student performing experiments on ac power plugs and resistors



westom said:


> Amusing is how much you will do to avoid labor.


I've said I wanted to perform the "experiment" and was simply asking what to expect from it. You've given me the cause, i'm simply asking for the effect.



westom said:


> A voltage less than 330 volts is completely ignored by any protector.


Yet I clearly defined that my protector kicks in at 136-142 volts.



westom said:


> What is +/- 5 to 7 percent change on 120 volts? I leave you to do the multiplication.


You are right, it would take a change of roughly 14 percent for my protector to kick in... hence why I'm having the POCO verify that the the flux is within reason.



westom said:


> If you ignore numbers, then you cannot possibly understand why 5:30 is also irrelevant. At most an anomaly created only because, well, that was also explained earlier.


I believe others explained the anomaly, something you refuted.



westom said:


> Tripping is not on a list of anomalies created by a surge.


I don't think anyone claimed that the gfci was directly tripped by the surge, rather the surge causing the protector to shunt to ground, causing the trip. Are you saying that a surge protector, when provided a surge, can not trip a GFCI? Please, a simple "yes" or "no" will suffice.



westom said:


> If you want an solution, then do that experiment; so simple that a 14 years old could do it.


I never claimed I couldn't do it, but I can guarantee you that 99% of 14 year olds couldn't even remotely guess what the effect would be (or even have an idea what a resistor is).


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> Buy a plug from Lowes. And two 100 Kohm (1/4 or 1/2 watt) resistors from Radio Shack (part number 271-1131). Connect two (or three) 100 Kohm resistors from the plug's hot prong to its safety ground prong. When that plug is connected to the GFCI circuit, then leakage will be about 2 (or 3) milliamps. Not enough to trip a GFCI. But maybe enough to trip that GFCI when a defective appliance (or defective wire in the wall) is also powered by that circuit.


Ok, let me take my best stab at this. By attaching these resistors from the plug's hot prong to the safety ground prong, I'm leaking about 2 or 3 milliamps to ground. By doing this test, you are having me prove that the 2-3 milliamp leak to ground will not trip the GFCI. But what is that proving that we don't already know (that it takes 5 milliamps to trip the GFCI)? Aren't we trying to find where the extra 5 milliamps are coming from?


----------



## gregzoll (Dec 25, 2006)

Only in the old days would they do it. They do not do it now, just like the same reason that majority of the high schools do not have shop classes theses days. Too much liability.

And yes, there are quite a few 14 year old's, that know what a resistor is. You would be surprised.


----------



## Billy_Bob (Sep 11, 2008)

ATJaguarX said:


> I've never heard of a junior high student performing experiments on ac power plugs and resistors.


You didn't know me when I was a kid! Actually I built a generator for the science fair when I was in elementary school.

I started all this when I took apart an electric train when I was 3 years old. My dad made the mistake of leaving me alone with the train and a screw driver for a few minutes....

But everybody is good at something. Other kids can play the piano quite well at an early age. I'm 50 and can't learn the piano to save my life! I'm just not good at that stuff...


----------



## gregzoll (Dec 25, 2006)

Billy Bob, I was the same way. I am 44, and can remember taking a DC motor from an Erector set and plugging into a wall outlet. Boy, did that thing fly, until it blew the breaker. Took a long time, before my dad let me play with anything electrical, whether it was dc or ac. Dad was a Radio Tech in the Air Force and worked for the telephone company for over thirty years, so growing up, we got to play with some really cool stuff, and always had boxes of resistors, capacitors, etc to play with.

I still remember helping dad build a Heathkit H-89 computer at age 12. Got his old ham radio receiver to play with at 14.


----------



## mpoulton (Jul 23, 2009)

westom said:


> How would you know? Purpose of an AC power plug and two resistors is not even understood. An experiment best given to a junior high school student because it is that trivial. Amusing is how much you will do to avoid labor.
> 
> Defined by others. A voltage less than 330 volts is completely ignored by any protector. What is +/- 5 to 7 percent change on 120 volts? I leave you to do the multiplication. If you ignore numbers, then you cannot possibly understand why 5:30 is also irrelevant. At most an anomaly created only because, well, that was also explained earlier.
> 
> ...


You're rather abrasive, and your involvement in this discussion has not been very helpful so far. For someone who clearly understands at least some of the underlying physics, you seem remarkably incapable of assembling all these puzzle pieces to provide a useful and intelligent contribution. This has not been a good introduction to the forum. Just an observation.

You still haven't provided any support for your clearly erroneous assertion that all surges are of too short a duration to trip a GFCI. Got any links?


----------



## westom (Aug 23, 2009)

ATJaguarX said:


> Aren't we trying to find where the extra 5 milliamps are coming from?


Everything necessary was posted multiple times. You need not ask any more questions. If that is too hard, then you are no longer amusing and did not want help. Do what was written.


westom said:


> Buy a plug from Lowes, et al. And two 100 Kohm (1/4 or 1/2 watt) resistors from Radio Shack (part number 271-1131). Connect two (or three) 100 Kohm resistors from the plug's hot prong to its safety ground prong. When that plug is connected to the GFCI circuit, then leakage will be about 2 (or 3) milliamps. Not enough to trip a GFCI. But maybe enough to trip that GFCI when a defective appliance is also powered by that circuit.


----------



## Billy_Bob (Sep 11, 2008)

gregzoll said:


> Billy Bob, I was the same way. I am 44, and can remember taking a DC motor from an Erector set and plugging into a wall outlet. Boy, did that thing fly, until it blew the breaker...


I didn't mention the ummm "other" experimenting I did such as the above.


----------



## gregzoll (Dec 25, 2006)

Now days, parents would have the authorities called on them, if their kids did what we did back in the day.


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> Everything necessary was posted multiple times. You need not ask any more questions. If that is too hard, then you are no longer amusing and did not want help. Do what was written.


I think I finally solved your riddle. Apparently it's easier to continue to post the riddle (over and over again) then to simply explain in details what should be done.

By performing the experiment (attaching resistors to the plug from hot to ground) brings the plug to roughly the gfci's threshold. I now have a device that I can plug my appliances into and determine which one will push the gfci past it's threshold.

If any device pushes the gfci past it's threshold, we have found the faulty device.


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> Connect two (or three) 100 Kohm resistors from the plug's hot prong to its safety ground prong.


In parallel or series?


----------



## Billy_Bob (Sep 11, 2008)

ATJaguarX said:


> In parallel or series?


In series. As you add more resistors in series, the higher the resistance and less current flowing.

So if just two in series trips the GFCI, then adding another in series would add additional resistance and have less current flowing.


----------



## kbsparky (Sep 11, 2008)

ATJaguarX said:


> I think I finally solved your riddle. Apparently it's easier to continue to post the riddle (over and over again) then to simply explain in details what should be done.
> 
> By performing the experiment (attaching resistors to the plug from hot to ground) brings the plug to roughly the gfci's threshold. I now have a device that I can plug my appliances into and determine which one will push the gfci past it's threshold.
> 
> If any device pushes the gfci past it's threshold, we have found the faulty device.


Problem here is you probably do NOT have any "faulty" devices. Your surge unit is doing its job. So is your GFCI device.

Your problem is the fact that both of these devices are doing what they were designed to do, and the result is nuisance tripping.

Waste of time, dealing with those resistors. A simple ETCON CT-101 plug tester has all that circuitry built-in. MUCH safer too!


----------



## ATJaguarX (Oct 16, 2011)

kbsparky said:


> Waste of time, dealing with those resistors. A simple ETCON CT-101 plug tester has all that circuitry built-in. MUCH safer too!


Thanks kbsparky! :thumbup: 

So, it looks like this device will test the GFCI to ensure that it is operating properly. To test if I have a faulty device, I would need a leakage current clamp meter... correct? Those are a bit out of my price range.


----------



## kbsparky (Sep 11, 2008)

That plug-in tester induces a leakage of 2mA. If you already have a leaking device with less than the trip threshold, plugging in the tester can trip out the GFCI without pressing the "test" switch.

Essentially does the same thing as using those wacky resistors, but without the dangers of exposed hot wires/connections.


----------



## ATJaguarX (Oct 16, 2011)

*Update*

Update

Last night, I did the following:


Moved my CyberPower UPS to a non gfci outlet (with my networking equipment plugged into it)
Plugged my surge protector into the GFCI (with nothing plugged into the surge protector)
Plugged my PowerShield UPS (from AT&T) into the GFCI (required for my phone)

I got up this morning and the GFCI was tripped (was only powering an empty surge protector and my PowerShield UPS). My CyberPower UPS had logged an "Event". So, the CyberPower, on a non-gfci outlet, had noticed this event.

Ironically, a few minutes later, I finally got a call back from the POCO. When I explained to him what was going on, his first thought was to look for a nearby capacitor bank.

A few hours later, he confirmed his thoughts. About 5 blocks away, is a capacitor bank that is scheduled to boost the voltage to my neighborhood at 5am. He is certain that the surge protector (or UPS) is picking up the extra voltage that the capacitor bank is injecting and nuisance tripping my GFCI.

I want to thank everyone who helped me in this situation! :thumbsup:


----------



## gregzoll (Dec 25, 2006)

That would make sense, since the majority of the load in the morning for people getting ready for work would be around 6 am. Boosting at 5 am means that they are getting the system ready for that extra load, when people are turning on exhaust fans, running curling irons, blow dryers, heating up stuff in microwaves for breakfast, kicking on the ac or heat. Would not be surprised if they boost the power around 5 pm also.


----------



## ATJaguarX (Oct 16, 2011)

gregzoll said:


> That would make sense, since the majority of the load in the morning for people getting ready for work would be around 6 am. Boosting at 5 am means that they are getting the system ready for that extra load, when people are turning on exhaust fans, running curling irons, blow dryers, heating up stuff in microwaves for breakfast, kicking on the ac or heat. Would not be surprised if they boost the power around 5 pm also.


The POCO tech claimed that the capacitor bank was necessary because of the industrial park. With the inrush of power to the industrial park, the bank introduces 1-2 extra volts to the neighborhood so that we are not affected.


----------



## gregzoll (Dec 25, 2006)

It is not just industrial areas, but all over a power grid. The capacitor banks do more than just keep the voltage constant, they also help to keep surges down. Here is some info in how they work http://www.btecentral.com/NTMC/capacitor_control.htm
http://arresterworks.com/ArresterFa... MOV Protection of Series Capacitor Banks.pdf
http://www.nepsi.com/ptcb.htm
http://www.southernstatesllc.com/applications/1-Capacitor-Switching


----------



## westom (Aug 23, 2009)

ATJaguarX said:


> The POCO tech claimed that the capacitor bank was necessary because of the industrial park. With the inrush of power to the industrial park, the bank introduces 1-2 extra volts to the neighborhood so that we are not affected.


 Not exactly. Capacitors compensate for reactive power. So that more utility power does actual (and billable) work. One symptom of compensating for reactive power may cause a near zero voltage change (1-2 volts). AC voltage changes exceeding 10 volts are perfectly normal for all electronics. Higher variations are ignored by all properly functioning GFCIs.

However, an appliance with excessive leakage can trip a GFCI when normal switching noise is created. Noise (not line voltage change) causes a slight increase in leakage current. How to find a defect that is causing a GFCI to be so sensitive? Was described previously.

Leakage typically would be greater than 2 ma to cause switching noise to trip a GFCI. Leakage that may be traceable to, for example, a damaged line filter inside some appliance due to a previous anomaly.

One can spend $27 for that circuit tester to locate the defect. Or do same for a few dollars with a plug and a few Radio Shacks resistors. Neither is dangerous - obviously - because a GFCI powers everything.

Capacitor bank only explains noise. The defect exists constantly. That always existing defect combined with perfectly normal noise would explain intermittent GFCI trips.

Nuisance tripping is never an acceptable event. Nuisance tripping is always traceable to a defect.


----------



## mpoulton (Jul 23, 2009)

ATJaguarX said:


> Update
> 
> Last night, I did the following:
> 
> ...


Cool. That's exactly what I (we) expected. I assume the POCO is going to do something about it? If switching in the capacitor bank is causing a voltage transient sufficient to trigger surge protection and bother UPSs, then something's not quite right with their cap bank.


----------



## ATJaguarX (Oct 16, 2011)

First I want to thank you westom for your knowledge and input. I have learned quite a bit from everyone on this forum. :thumbsup:

Now to my questions:



westom said:


> Leakage that may be traceable to, for example, a damaged line filter inside some appliance due to a previous anomaly.


Just to confirm, the leakage would have to be from an appliance on the same circuit(breaker)?



westom said:


> One can spend $27 for that circuit tester to locate the defect. Or do same for a few dollars with a plug and a few Radio Shacks resistors. Neither is dangerous - obviously - because a GFCI powers everything.


To me, the Radio Shack route is dangerous because I am not an electrician and have not been provided DETAILED instructions on how to create this device. Since basic tasks as how the resistors should be wired (in parallel or series) were not explained, I'm not comfortable that I have everything I need to make this device.


----------



## ATJaguarX (Oct 16, 2011)

mpoulton said:


> Cool. That's exactly what I (we) expected. I assume the POCO is going to do something about it? If switching in the capacitor bank is causing a voltage transient sufficient to trigger surge protection and bother UPSs, then something's not quite right with their cap bank.


The POCO made no effort to do anything about it. He claimed that the capacitor bank is operating as designed. He simply thought that I had really good surge protectors and told me to remove the GFCI and replace it with a regular outlet.

The POCO claimed that the capacitor bank should only be causing a voltage transient of 1-2 volts. I recently had a control board go out in my furnace (only 4 years old)... I wonder if the capacitor bank is responsible for that.


----------



## westom (Aug 23, 2009)

ATJaguarX said:


> To me, the Radio Shack route is dangerous because I am not an electrician and have not been provided DETAILED instructions on how to create this device.


Long before GFCIs existed, a GFCI designer demonstrated it to the press. I found this test so unacceptable that I will never forget it. He had his daughter in a bathtub. Then he threw a powered appliance into that bathtub. She was unharmed. He proved his point. But …

 GFCI means you could be holding those resistors when powered. And never be harmed. However, like the girl in a tub, I do not recommend it. I am always that cautious.

 Connect three 100 Kohm resistors in parallel from the hot (typically tinted copper colored) wire connection to the safety ground (typically tinted green) wire connection. Reassemble that plug. Plug it into one of two GFCI outlets. That should make the GFCI more sensitive to any partially leaking appliance. IOW, a few milliamps leaking inside an appliance would trip a GFCI that already has 2+ ma leaking through that test plug.

 Now, this test has no danger and multiple layers of safety. But it always remains a thrill to connect something for the first time. Part of why I so enjoy doing things. And why I always stand back when even connecting anything I believe should never fail. Fear even of the impossible is exciting. Oh. And Happy early Halloween.

 I went back and setup a custom GFCI tester I had built. It is adjustable. I set it for a leakage of 4.5 ma. Could not get noise from any adjacent appliance (vacuum, fluorescent lamp, etc) to trip it. Noise did trip that GFCI when I setup a leakage of 4.8 ma.

 Now the math. From ohms law where voltage equals current times resistance. Three 100 Kohm resistors in parallel is 33K. 120 volts divided by 33K is the leakage current. About 3.6 milliamps.

 If using two resistors, 120 volts divided by 50 Kohms (two resistors in parallel) resistance is 2.4 milliamps leaking from hot to safety ground. Neither should cause the GFCI to trip.

 If I remember, your GFCI is in a breaker box. Therefore leakage may also be in wires inside the wall. Another viable suspect; but only after the test is done.

 Since you now have a another relevant item (switching capacitors), then you might try the test plug overnight with two resistors and later with three resistors. With the GFCI not powering anything else. To provide further insight into noise from that capacitor bank.

 Surge protectors ignore voltages below 330 volts. That let-through voltage is written on each box. Capacitor bank would never create 330 volts on 120 volt service. (Other electrical parameters may be relelvant - just not here and not yet.) 

 And finally, curiosity. Who is the GFCI manufacturer? There might be information unique to his design.


----------



## mpoulton (Jul 23, 2009)

ATJaguarX said:


> The POCO made no effort to do anything about it. He claimed that the capacitor bank is operating as designed. He simply thought that I had really good surge protectors and told me to remove the GFCI and replace it with a regular outlet.
> 
> The POCO claimed that the capacitor bank should only be causing a voltage transient of 1-2 volts. I recently had a control board go out in my furnace (only 4 years old)... I wonder if the capacitor bank is responsible for that.


That's not good. If your UPS detected the event, it's not a 1-2V transient. That wouldn't cause the surge protection/GFCI issue, either. I think you should request that they do power quality monitoring. Most POCOs have portable power quality monitors they can install temporarily to record issues like this and figure out what's going on. Does your UPS log any quantitative data about power quality events, like the line voltage?


----------



## ATJaguarX (Oct 16, 2011)

mpoulton said:


> That's not good. If your UPS detected the event, it's not a 1-2V transient. That wouldn't cause the surge protection/GFCI issue, either.


My UPS is currently set at the "High Sensitivity" setting. It switches to battery power under 88Vac or over 136Vac. To me... this is telling me that it picked up at least 136Vac.



mpoulton said:


> I think you should request that they do power quality monitoring. Most POCOs have portable power quality monitors they can install temporarily to record issues like this and figure out what's going on.


I'll call the POCO back and request that they install a power quality monitor.



mpoulton said:


> Does your UPS log any quantitative data about power quality events, like the line voltage?


I don't believe my UPS logs any real data. It does tell me the current Vac (which usually swings between 121 and 123). I'll have to look to see how I can get any more data out of the logs (if I can).



westom said:


> If I remember, your GFCI is in a breaker box. Therefore leakage may also be in wires inside the wall. Another viable suspect; but only after the test is done.


My GFCI is attached to the side of the breaker box and is the only outlet on the circuit/breaker.



westom said:


> Since you now have a another relevant item (switching capacitors), then you might try the test plug overnight with two resistors and later with three resistors. With the GFCI not powering anything else. To provide further insight into noise from that capacitor bank.


Thank you for the idea... I'll try that too!



westom said:


> Surge protectors ignore voltages below 330 volts. That let-through voltage is written on each box. Capacitor bank would never create 330 volts on 120 volt service.


My UPS kicks in at 136Vac.



westom said:


> And finally, curiosity. Who is the GFCI manufacturer? There might be information unique to his design.


Pass & Seymour 2095-WCC10


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> One can spend $27 for that circuit tester to locate the defect. Or do same for a few dollars with a plug and a few Radio Shacks resistors. Neither is dangerous - obviously - because a GFCI powers everything.


I actually picked up this circuit tester for less then $10. If it doesn't fill the need, I'll build the one that you described.

Thanks for explaining in detail on how to build the tester, how to use it and what to expect. It has helped me better understand the issue and how to troubleshoot it. :thumbup:


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> Do the experiment.
> 
> Buy a plug from Lowes. And two 100 Kohm (1/4 or 1/2 watt) resistors from Radio Shack (part number 271-1131). Connect two (or three) 100 Kohm resistors from the plug's hot prong to its safety ground prong. When that plug is connected to the GFCI circuit, then leakage will be about 2 (or 3) milliamps. Not enough to trip a GFCI. But maybe enough to trip that GFCI when a defective appliance (or defective wire in the wall) is also powered by that circuit.


I did the experiment with (3) 100 Kohm resistors. No appliances tripped the GFCI. :thumbup:


----------



## westom (Aug 23, 2009)

ATJaguarX said:


> I did the experiment with (3) 100 Kohm resistors. No appliances tripped the GFCI.


 Ok. Now use the same tester plug on the GFCI with nothing else connected. Let's see if the capacitor bank switching causes GFCI tripping through that 3+ ma leakage.

 At this time of year, electric usage is particularly low at night. The grid has a problem. Too many generators and not enough load. So they disconnect those capacitors to make the grid less efficient. Because generators cannot be turned off overnight.

 Your capacitor may be switching only on weekday mornings as load increases significantly. But a more constant weekend load may mean those same capacitors remain unswitched. This test should continue even into the weekdays. Or unless test plug leakage causes a trip during the weekend.


----------



## ATJaguarX (Oct 16, 2011)

westom said:


> Your capacitor may be switching only on weekday mornings as load increases significantly. But a more constant weekend load may mean those same capacitors remain unswitched.


I experienced a trip last Sunday morning. We'll try tomorrow morning and see what happens.


----------



## ATJaguarX (Oct 16, 2011)

*Picture*

Here is a picture of my device


----------

