# Burnt out led



## TrArKi (Jul 4, 2016)

Oh and voltage tests fine at every light. And the lights have a led driver similar to a flourescent ballast.


----------



## TrArKi (Jul 4, 2016)

Oh and the led driver has a seperate 0-10v dimming option not used.


----------



## B-Nabs (Jun 4, 2014)

Teach that kid how to use a low voltage toner. Or fire his ass.


----------



## MechanicalDVR (Dec 29, 2007)

Hire a new apprentice, it will be cheaper in the long run. If he got shocked from the open neutral connections and hurt while testing guess whose insurance that would have been on?


----------



## Drew 64 (Dec 31, 2016)

Hard to tell from your post exactly what type of lighting you have.
I can tell you that opening a neutral , with power still applied, on many electronic circuits = smoked............


----------



## LGLS (Nov 10, 2007)

TrArKi said:


> Im working at a school thats using all led lighting. Most of the lighting is either 1x4 or 2x4 layin tbar troffers. All 347v.
> Now an apprentice was splicing a admin area and the neutrals were missing labels. So he decided to turn power on and unsplice already spliced and finished neutrals and then check which lights were off to match the set with the hots. Ok clever. However every light on that neutral started strobing ( like I've seen with flourescents) and a smell of burnt wiring came down the hall. So he quickly deenergized the lights re connected the splice and called me. We re-energized and he looked for burnt out lights. He found 3. A day or 2 later there was a dead short that caused the main to trip ( we dont know why). After that there was a entire classroom lights out. And the bathroom. The bathroom has 2 pots at the end of the chain still on. The pots have a transformer at each one to step down from 347 to 120v. We're not sure if the bathroom and classroom were working after neutral incident. But its 12 fixtures in a classroom only with other classrooms on same circuit that are fine. Im not sure if this is clear but any ideas?


Who the hell labels neutrals?


----------



## Cow (Jan 16, 2008)

I see this more as a training/management issue, somebody doesn't seem to be doing their job.

1. Why does the apprentice think it's okay to splice/unsplice wires hot?

2. Why hasn't anyone explained to him what happens when you break the neutral connection on a live circuit?


----------



## Spark Master (Jul 3, 2012)

Once that neutral opened up, the voltage spiked from 120v to probably close to 200v.


----------



## frenchelectrican (Mar 15, 2007)

Spark Master said:


> Once that neutral opened up, the voltage spiked from 120v to probably close to 200v.


That true but as long you look at OP's comment he did say 347 volts so if he open the netual it will kick up about 600 volts depending on what it is connected. 

That is fastest smoke making event on that voltage level. 

As far for newbie working on the multi branch circuit there is a golden rules .,,

Anytime ya see more just two colours that will give you a clue that is more than one circuit is on ( that do not count the ground due it always green ) and when ya lift the netural it will affect the circuits.
Even ya think turn off a single breaker will take care this ??? the answer is no because you have to look more closer to the junction box to see the number of circuits in there.


----------



## Southeast Power (Jan 18, 2009)

TrArKi said:


> Im working at a school thats using all led lighting. Most of the lighting is either 1x4 or 2x4 layin tbar troffers. All 347v.
> Now an apprentice was splicing a admin area and the neutrals were missing labels. So he decided to turn power on and unsplice already spliced and finished neutrals and then check which lights were off to match the set with the hots. Ok clever. However every light on that neutral started strobing ( like I've seen with flourescents) and a smell of burnt wiring came down the hall. So he quickly deenergized the lights re connected the splice and called me. We re-energized and he looked for burnt out lights. He found 3. A day or 2 later there was a dead short that caused the main to trip ( we dont know why). After that there was a entire classroom lights out. And the bathroom. The bathroom has 2 pots at the end of the chain still on. The pots have a transformer at each one to step down from 347 to 120v. We're not sure if the bathroom and classroom were working after neutral incident. But its 12 fixtures in a classroom only with other classrooms on same circuit that are fine. Im not sure if this is clear but any ideas?


Call the distributer, let them know you had an out of box failure and threaten to back charge them of they dont get some replacements onsite in two days.


----------



## MechanicalDVR (Dec 29, 2007)

Suncoast Power said:


> Call the distributer, let them know you had an out of box failure and threaten to back charge them of they dont get some replacements onsite in two days.


Should have been done as soon as it was discovered.


----------



## TrArKi (Jul 4, 2016)

Spark Master said:


> Once that neutral opened up, the voltage spiked from 120v to probably close to 200v.


Why, where does the extra voltage come from and how would you test?







Cow said:


> I see this more as a training/management issue, somebody doesn't seem to be doing their job.
> 
> 1. Why does the apprentice think it's okay to splice/unsplice wires hot?
> 
> 2. Why hasn't anyone explained to him what happens when you break the neutral connection on a live circuit?



someone gave him the idea. 
Oh i have now.






Suncoast Power said:


> Call the distributer, let them know you had an out of box failure and threaten to back charge them of they dont get some replacements onsite in two days.


I believe thats what my pm has done. We actually had to return one for them to test.


----------



## TrArKi (Jul 4, 2016)

frenchelectrican said:


> That true but as long you look at OP's comment he did say 347 volts so if he open the netual it will kick up about 600 volts depending on what it is connected.
> 
> That is fastest smoke making event on that voltage level.
> 
> ...


But there was 2 other circuits on that neutral and on the circuit that it happened, it was only in one classroom.
I believe it came down to lazyness. Turning circuits off and continuity to ground to find it, would of been my choice.
But why would i get 600v on one leg. 600v is across 2 phases.
I know theres a voltage spike because ive been told but why?


----------



## Camera_Man (Feb 19, 2017)

LawnGuyLandSparky said:


> Who the hell labels neutrals?


The only time I've had to label Neutrals and Grounds is with a company who built enclosures for power generators. The customer wanted EVERYTHING labeled at both ends. Lights, switches, outlets, heaters, you name it, it got labeled.


----------



## HackWork (Oct 2, 2009)

LawnGuyLandSparky said:


> Who the hell labels neutrals?


Any time I label a hot I also label the corresponding neutral. That's why brady markers break in half. You pull off the number sticker and start wrapping it around the hot, then pull it to break it in half and wrap the other half around the neutral. 

When sharing a neutral, such as using it for circuits 5, 7, and 9, I would put all 3 of those numbers on the neutral.

How else would you do it? If you have multiple 3-phase sets coming into a box, how would you know what neutral to use and be sure that you're not overloading it?


----------



## LGLS (Nov 10, 2007)

HackWork said:


> Any time I label a hot I also label the corresponding neutral. That's why brady markers break in half. You pull off the number sticker and start wrapping it around the hot, then pull it to break it in half and wrap the other half around the neutral.
> 
> When sharing a neutral, such as using it for circuits 5, 7, and 9, I would put all 3 of those numbers on the neutral.
> 
> How else would you do it? If you have multiple 3-phase sets coming into a box, how would you know what neutral to use and be sure that you're not overloading it?


I would label them same as you. But not to each individual fixture. The OP said something about determining which circuit a particular fixture was on. I should have said "why pull a neutral" instead of why label a neutral.


----------

