# unsteady lights on outlet tester



## waco (Dec 10, 2007)

First and always, bypass the GFCI and see what happens.


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## 480sparky (Sep 20, 2007)

Why is there GFIs in a classroom?


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## manchestersparky (Mar 25, 2007)

Second sentence :
"Trouble ticket No power in outlets above sinks"


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## 480sparky (Sep 20, 2007)

manchestersparky said:


> Second sentence :
> "Trouble ticket No power in outlets above sinks"


So ?


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## patriot1 (Feb 16, 2009)

I would lose the GFCI behind the desk first of all. Could have a neutral/ground crossed somewhere along the line. 

I worked on a xfmr 120/208 to 120/240 for isolation on a computer panel. The neutral was ran from the main panel straight to the comp. panel and so was the ground. The only wires going to xfmr was power in and power out. Someone thought this would work but it did not. I bonded the xfmr removed the original neutral and caught the neutral from the xfmr, worked like a charm.


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## goose134 (Nov 12, 2007)

> Why is there GFIs in a classroom?


Maybe a science class with sinks.


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## manchestersparky (Mar 25, 2007)

480sparky said:


> So ?


I'm sure that the GFCI protection was not required when the school was built. Keep in mind that the NEC is a minimum requirement. You can above and beyond,yes I know you know this.

In my part of the globe,It is standard operating prodedure to install GFCI protection close to any sink required or not. 

Safety first type of thing. I'm sure thats why the GFCI in the classroom.

SO I ask YOU - why not?


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## 76nemo (Aug 13, 2008)

Be nice to know what exactly the led's indicated:blink:


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## waco (Dec 10, 2007)

I agree with manchestersparky. Why not?


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## jfwfmt (Jul 5, 2008)

School built 3 years ago.
Science classroom.
Sinks.
Even in schools built 107 years ago we install GFCIs at sinks.


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## MDShunk (Jan 7, 2007)

Here's a few things I'd do....

bypass the GFCI and take your volt measurements again
take those same measurements at the branch breaker terminal for that circuit
take those same measurements at the lugs feeding the panel that branch breaker is in.
divide and conquer, with a loose connection or voltage drop in mind (heavy load on panel OR your particular branch circuit), all depending on what the above measurements tell you.


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## 480sparky (Sep 20, 2007)

jfwfmt said:


> School built 3 years ago.
> Science classroom.
> Sinks.
> Even in schools built 107 years ago we install GFCIs at sinks.


Not a bad idea, but not required.


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## JohnJ0906 (Jan 22, 2007)

480sparky said:


> Not a bad idea, but not required.


Not when that school was built, but required under the '08 (within 6' of the sink)

210.8(B)(5)


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## JohnJ0906 (Jan 22, 2007)

I would begin the same way as Marc - remove the GFCI and test again.



jfwfmt said:


> BUT the two yellow lights on the outlet tester are now on, sort of blinking. Check voltage Hot to Neutral in outlet -- 123 117 121 119 ...


Did you also test hot-EGC?
How fast is the fluctuating?


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## jfwfmt (Jul 5, 2008)

*Tester characteristics*



76nemo said:


> Be nice to know what exactly the led's indicated:blink:


The tester is a GB GFI-501 rated 125V 0.3W

It consists of three neon lights each in series with a limiting resistor wired in the following arrangement:

L1 (yel): grounding to hot
L2 (yel): neutral to hot
L3 (red): grounding to neutral

Ignition voltage for a neon light is around 90VAC RMS

It also has a pushbutton wired in series with a resistor which passes approx 6mA at 125VAC. This is wired between grounding and hot. It is used to test the trip function of a personal protection GFCI

/s/ Jim WIlliams


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## MDShunk (Jan 7, 2007)

jfwfmt, don't read anything into this question... how long you been doing service?


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## jfwfmt (Jul 5, 2008)

*is playing Dumb ok?*



MDShunk said:


> jfwfmt, don't read anything into this question... how long you been doing service?


About 3 years. This is the first time I've seen an outlet tester blink instead of being on or off. I thought it was an interesting "reading" from the tester.

I also used a slow response DVM which gave the readings noted in first post.

I have a 90% confidence that it is loose connections in the panelboard. We have found two other panelboards in this NEW building with loose connections from the hot buses to the boltin breakers. 

We are planning to go to our boss and ask permission to work second shift this coming week in the school and go around and tighten all branch circuit panel boards.

I often post things here that I find interesting in the hopes that my experiences can help other fellow electricians.


Is it proper to post open questions when I have a pretty good idea of the answer??

Thanks,

/s/ Jim WIlliams


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## MDShunk (Jan 7, 2007)

jfwfmt said:


> Is it proper to post open questions when I have a pretty good idea of the answer??


You betcha, it's proper. What sometimes gets other forum members upset is when you post a question as if you have no idea, hoping for some good feedback, only to later reply that you already ruled in or out certain things and have a pretty good idea it's XYZ, or whatever. It's best to lay all your cards out on the table from the beginning, sorta like "...I think I'm dealing with a loose connection because of...., what do you guys think?", type of deal. 

Some guys like to post a question as if it's an unresolved problem too, get a number of responses, then reply with what the actual problem was (when they knew it all along). That's not nice... If a guy wants to post a pop quiz, he shouldn't word it like he's seeking help.


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## jfwfmt (Jul 5, 2008)

JohnJ0906 said:


> I would begin the same way as Marc - remove the GFCI and test again.
> 
> 
> 
> ...


Without the history of bad connections in the panelboards, I would check the GFCI first.

Both hot to EGC and hot to neutral are acting the same, both blinking, so I'm guessing the hot is the loose one. The blinking is so fast that the two yellow lights appear dim, but have no visible blinking.

Thanks,

/s/ Jim WIlliams


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## jfwfmt (Jul 5, 2008)

*Wiring above and beyond code at time of construction*

I work in a school system.
I can afford being fired at any time.
I feel my real job is to make sure no one gets hurt by electricity and electricity causes no fires.

As soon as the 2008 NEC came out we electricians decided to "adopt" it. There are no, none, nada electrical inspectors that check our work beyond the service entrance. We decided that the added safety features in 2008 were worth applying immediately.

If anyone has a problem with that, they can get themselves a new electrician.

/s/ Jim WIlliams


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## itsunclebill (Jan 16, 2007)




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## MDShunk (Jan 7, 2007)

jfwfmt said:


> I work in a school system.
> I can afford being fired at any time.
> I feel my real job is to make sure no one gets hurt by electricity and electricity causes no fires.
> 
> ...


Nothing wrong with that. The building owner's specs are often more strict than the NEC. Same with the insurance company's rules. Just ask anyone who's ever worked in a place insured by Factory Mutual. I'm doing some work in an older office building right now that has all kinds of wacky energy conservation rules. A B switching everywhere, etc.


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## jfwfmt (Jul 5, 2008)

MDShunk said:


> You betcha, it's proper. What sometimes gets other forum members upset is when you post a question as if you have no idea, hoping for some good feedback, only to later reply that you already ruled in or out certain things and have a pretty good idea it's XYZ, or whatever. It's best to lay all your cards out on the table from the beginning, sorta like "...I think I'm dealing with a loose connection because of...., what do you guys think?", type of deal.
> 
> Some guys like to post a question as if it's an unresolved problem too, get a number of responses, then reply with what the actual problem was (when they knew it all along). That's not nice... If a guy wants to post a pop quiz, he shouldn't word it like he's seeking help.


I was actually trying to see if anyone else has seen one of these neon testers act that way. Checking the GFCI is a good idea that I wouldn't have thought of, since my partner said I saw loose connections in other panelboards in this building. Checking the GFCI is something we can do tomorrow morning with students in the building and we'll probably do it. Also being reminded to test the GFCI may serve me well in other buildings.

Thanks,

/s/ Jim WIlliams


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## waco (Dec 10, 2007)

Another thing to think about; is it possible you have two GFCIs interacting? Is there any way the feed is a MWBC with two GFCIs sharing a neutral?


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## 480sparky (Sep 20, 2007)

jfwfmt said:


> I work in a school system.
> I can afford being fired at any time.
> I feel my real job is to make sure no one gets hurt by electricity and electricity causes no fires.
> 
> ...


So, who pays for all that extra stuff?


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