# Why wouldn't breaker trip?



## 480sparky (Sep 20, 2007)

If it's not a 'dead' short, there may be enough resistance in the fault to prevent the breaker from tripping.

Or they have FPE breakers.


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## asparky (Nov 29, 2013)

Def a dead short wires in old fixture melted together. Even checked continuity with meter when I was finished...


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## 480sparky (Sep 20, 2007)

So you had to turn the breaker off?

If so, you should have replaced it since it's obviously not doing it's job.


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## Maple_Syrup25 (Nov 20, 2012)

Could it have been fed from 2 breakers perhaps?


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## BBQ (Nov 16, 2010)

asparky said:


> Def a dead short wires in old fixture melted together. Even checked continuity with meter when I was finished...


In that case what prevented a fire?


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## asparky (Nov 29, 2013)

Located and turned off breaker to bedroom circuit and rewired then turned off switch to hallway light fixtures and replaced them. I did replace the breaker to the hallway fixtures as a precaution. Assumed that the added neutral wire was the culprit.


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## 480sparky (Sep 20, 2007)

Maple_Syrup25 said:


> Could it have been fed from 2 breakers perhaps?


And that prevents them opening......... why?


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## asparky (Nov 29, 2013)

Located and turned off breaker to bedroom circuit and rewired then turned off switch to hallway light fixtures and replaced them. I did replace the breaker to the hallway fixtures as a precaution. Assumed that the added neutral wire was the culprit. There was still one lamp in one of the fixtures that was on. ( three lamps per fixture. Breaker never tripped...


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## Maple_Syrup25 (Nov 20, 2012)

Not sure man just tossing it out there, learn me something... I just remember working on some 347 volt lighting that was fed from 3 different breakers that we had a lot of trouble with, just reminded me of that job


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## asparky (Nov 29, 2013)

Ha not sure why the breaker didn't trip that's where I was confused?


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## BBQ (Nov 16, 2010)

480sparky said:


> Or they have FPE breakers.


Why do you insist in continuing that myth?


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## 480sparky (Sep 20, 2007)

BBQ said:


> Why do you insist in continuing that myth?


That Fire Producing Equipment breakers don't trip?

Because some don't.


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## asparky (Nov 29, 2013)

Was very close to a fire insulation in fixture was melted and burn marks on drywall...


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## 76nemo (Aug 13, 2008)

:laughing:


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## BBQ (Nov 16, 2010)

480sparky said:


> That Fire Producing Equipment breakers don't trip?
> 
> Because some don't.


You are right, and the same can be said of every brand.


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## 10492 (Jan 4, 2010)

asparky said:


> Ha not sure why the breaker didn't trip that's where I was confused?


You have a loose connection somewhere before the light circuit that opened during a large inrush...when the wires in the light fused together.



Just a guess...


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## 8V71 (Dec 23, 2011)

asparky said:


> Def a dead short wires in old fixture melted together. Even checked continuity with meter when I was *finished*...





asparky said:


> There was still one lamp in one of the fixtures that was on. ( three lamps per fixture. Breaker never tripped...


I don't think you had a short. My guess is that there was a loose connection that melted the insulation together but never actually created a short. If you had a short it would be impossible for a light to still be lit.


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## Big John (May 23, 2010)

It was a short, but it may have been relatively high resistance, or relatively fast. 

You need a certain amount of current flow that lasts for a certain amount of time to trip a breaker. If either one of those isn't satisfied, the breaker isn't going to operate, even if it's working properly.


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## macmikeman (Jan 23, 2007)

I came across an FPE plug in 20 amp breaker a couple of weeks back that went against the grain and tripped , resulting in customer contacting me to find short. FPE was a very popular panel here for a long time. If I was full of cool aid like most here are I could have made an empire out of peddling FPE replacements for big money and no real local evidence of proof that they never trip during overloads or shorts. 

I challenge 480 to make a suicide switch box up and do some purposeful trip tests on plug in (residential.. no need to kill the poor guy to prove a point..) FPE breakers in a You Tube video to show us all how evil they are.


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## pete87 (Oct 22, 2012)

Sure it wasn't a 100W bulb in a 60W max fixture and insulation not installed ?


Just Sayin .



Pete


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## owl (Oct 31, 2012)

480sparky said:


> If it's not a 'dead' short, there may be enough resistance in the fault to prevent the breaker from tripping.
> 
> Or they have FPE breakers.


What is a dead short?


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## bkmichael65 (Mar 25, 2013)

owl said:


> What is a dead short?


Line to line contact bypassing any load


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## RIVETER (Sep 26, 2009)

asparky said:


> Went to a house to change two hallway fixtures that the home owner has been having trouble with. Pulled first one down the wires were melted together and burn spots on the drywall. Saw an added wire with just the neutral wire connected in box. ( hot wire was not connected to anything.) Traced wire to an added ceiling fan in a bedroom they pulled a Romex to the switch in the room (which was originally controlling a receptacle) to get the hot. Got everything rewired and all is good but am not sure why the breaker didn't trip due to the short in the light fixture?


There was no short circuit.


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## dspiffy (Nov 25, 2013)

480sparky said:


> That Fire Producing Equipment breakers don't trip?
> 
> Because some don't.


I've seen this firsthand in multiple cases.


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## ScholzPDX (Jul 24, 2013)

480sparky said:


> If it's not a 'dead' short, there may be enough resistance in the fault to prevent the breaker from tripping.
> 
> Or they have FPE breakers.





BBQ said:


> Why do you insist in continuing that myth?


It's real. Why do you insist it's a myth?

Even a first term apprentice knows you're dead wrong.


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## guest (Feb 21, 2009)

> Originally Posted by *BBQ*
> _Why do you insist in continuing that myth?_





> It's real. Why do you insist it's a myth?
> 
> Even a first term apprentice knows you're dead wrong.


Oh, boy.....little advice for the new guy: don't challenge BBQ, you WILL lose. (Not saying you're wrong, but don't challenge "the other white meat", it is not worth it.) :laughing:


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## Big John (May 23, 2010)

ScholzPDX said:


> It's real. Why do you insist it's a myth?
> 
> Even a first term apprentice knows you're dead wrong.


 Good thing I don't get my info from first term apprentices. :laughing: 

I'm not sure whether it's a valid argument or not. I've tested some. I've heard from other guys who've tested some. The consensus so far is they don't react any differently than any other old breaker, which is to say they aren't good, but no breaker 40 year old molded case is going to be. And they all tripped.


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## BBQ (Nov 16, 2010)

ScholzPDX said:


> It's real. Why do you insist it's a myth?
> 
> Even a first term apprentice knows you're dead wrong.


Can you produce proof of this?


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## guest (Feb 21, 2009)

BBQ said:


> Can you produce proof of this?


If he can I'll bet it's gonna be anecdotal......:whistling2::laughing:


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## dspiffy (Nov 25, 2013)

All I can say, is I've personally seen FPE breakers not trip when faced with a dead short in multiple and varied instances. I cant say that about any other brand of breakers.


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## ScholzPDX (Jul 24, 2013)

BBQ said:


> Can you produce proof of this?


http://www.nbcbayarea.com/Federal-P...gation-Finds-Decades-of-Danger-171406921.html

Have anything credible to the contrary?

I'll bet it's gonna be anecdotal......


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## Big John (May 23, 2010)

ScholzPDX said:


> ...Have anything credible to the contrary...


 I tested some.

It's not definitive, but they all tripped like they should've. Seems a little contrary to what everyone says about them.


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