LED burning at 277v circuit

James L

Senior Member
Location
Kansas Cty, Mo, USA
Occupation
Electrician
What is voltage at luminaire(s)?

if you have a bad neutral, maybe multiwire circuit or a feeder with a bad neutral you maybe not too unbalanced initially, but as more drivers fail unbalancing gets worse and impacts more drivers. The ones that see lower volts are probably fine, the ones that see higher volts is what is likely failing if this is what is going on, but that don't mean it won't change after enough fail the load balancing can be significantly different than it originally was.

285 is pretty common to see around here on what is supposed to be 277 nominal, that is only about 3% above 277 and should be acceptable.
A lot of Amazon lighting I've looked at with a range of 100 - ??? is actually only rated to go to 265v and could probably work up to 277

If that's the case they might just "say" it's rated at 277 and hope the voltage isn't any higher.

That's why I asked what brand and where he bought it. I've bought a considerable amount of Amazon lighting, and I know some Chinese shenanigans
 

hillbilly1

Senior Member
Location
Atlanta,Ga
Is the wiring method Reloc or some other manufactured system? Burnt Neutral pins are common on the multi circuit connectors. Causes an “Open” neutral condition that will fry some of the drivers that happen to be on the leg that goes high. Because they are multi volt, the low leg will operate at rated output.
 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
Is the wiring method Reloc or some other manufactured system? Burnt Neutral pins are common on the multi circuit connectors. Causes an “Open” neutral condition that will fry some of the drivers that happen to be on the leg that goes high. Because they are multi volt, the low leg will operate at rated output.
Very good point. Multi-volt operation that maintains a constant power level is effectively a negative resistance because the current increases when the voltage is reduced (and vice versa). That makes them tend to exacerbate and worsen any voltage imbalance on MWBCs when there's excess resistance in the neutral path.
 

Jchamos

Member
Location
Indianapolis
Occupation
Electrician
A lot of Amazon lighting I've looked at with a range of 100 - ??? is actually only rated to go to 265v and could probably work up to 277

If that's the case they might just "say" it's rated at 277 and hope the voltage isn't any higher.

That's why I asked what brand and where he bought it. I've bought a considerable amount of Amazon lighting, and I know some Chinese shenanigans
lighting distribuidor out of atlanta
I’ll look the exact brand !
but yes I will be at the site in the next couple of days and try to look all the facts
 

Jchamos

Member
Location
Indianapolis
Occupation
Electrician
Very good point. Multi-volt operation that maintains a constant power level is effectively a negative resistance because the current increases when the voltage is reduced (and vice versa). That makes them tend to exacerbate and worsen any voltage imbalance on MWBCs when there's excess resistance in the neutral path.
Is the wiring method Reloc or some other manufactured system? Burnt Neutral pins are common on the multi circuit connectors. Causes an “Open” neutral condition that will fry some of the drivers that happen to be on the leg that goes high. Because they are multi volt, the low leg will operate at rated output.
very good point sir
Yes a one of this PIN push manufactured connectors along the whole store
Former target
 

Flicker Index

Member
Location
Pac NW
Occupation
Lights
Putting a transient event logger where the failure occurred and monitor in between L-N; and/or (if you have additional channels available) N-G is a good way to track loose neutral issues and honestly this is a good idea before you fry any more LED ballasts. These days, a good majority of ballasts are 120-277v and when you're dealing with 120v circuit, they're exposed to over voltage but stay within this range. Depending on the ballast's regulation performance, you'll see very noticeable shimmering and flickering or nothing at all. However, on a 277v, a loose neutral can go well beyond the rated voltage. If you don't have the right test equipment, even putting a DMM with "peak hold" (not min/max) in between EGC and neutral and keeping an eye on it can provide useful information.

What was in place before the retrofit, magnetic ballasts or electronic? The reason I ask is that magnetic ballasts are basically immune to fractional second exposure to neutral lift. It'd have to be exposed to over voltage condition long enough to burn out the coil or exposed to high enough over voltage to arc over.
 

Jchamos

Member
Location
Indianapolis
Occupation
Electrician
Putting a transient event logger where the failure occurred and monitor in between L-N; and/or (if you have additional channels available) N-G is a good way to track loose neutral issues and honestly this is a good idea before you fry any more LED ballasts. These days, a good majority of ballasts are 120-277v and when you're dealing with 120v circuit, they're exposed to over voltage but stay within this range. Depending on the ballast's regulation performance, you'll see very noticeable shimmering and flickering or nothing at all. However, on a 277v, a loose neutral can go well beyond the rated voltage.

What was in place before the retrofit, magnetic ballasts or electronic? The reason I ask is that magnetic ballasts are basically immune to fractional second exposure to neutral lift. It'd have to be exposed to over voltage condition long enough to burn out the coil or exposed to high enough over voltage to arc over.
thank you so much
What is exactly the name of the equipment I can use to record voltage issues ?

electronic t8ballast 4 bulbs were in place before
 

Flicker Index

Member
Location
Pac NW
Occupation
Lights
thank you so much
What is exactly the name of the equipment I can use to record voltage issues ?

electronic t8ballast 4 bulbs were in place before
Voltage event recorder is what it's called. You could use a tool like this too, but there's some learning curve:

Do you have a Fluke 87? Use alligator clips to tightly connect leads in between neutral and ground under load. Manually put the meter on 1000v range, then use not min/max, but "peak hold". Make sure they don't come off. If they do, the readings will shoot all over the place and you have to reset it from the start. Everything all set, it's normal to see 10-20v, but keep on the look out for hundreds of volts. If there's a neutral lift, then you'll read several hundred volts between N-G.

That needs to be setup near the fixture where the issue is.

Was the wiring disturbed during the retrofit other than at the fixture? If all of the existing ballasts were fine and wiring wasn't disturbed at the panel, the new ballasts design might be the issue, but if you do observe loose neutral related voltage disturbance, that's not really something that has to be covered under warranty.
 

kwired

Electron manager
Location
NE Nebraska
Putting a transient event logger where the failure occurred and monitor in between L-N; and/or (if you have additional channels available) N-G is a good way to track loose neutral issues and honestly this is a good idea before you fry any more LED ballasts. These days, a good majority of ballasts are 120-277v and when you're dealing with 120v circuit, they're exposed to over voltage but stay within this range. Depending on the ballast's regulation performance, you'll see very noticeable shimmering and flickering or nothing at all. However, on a 277v, a loose neutral can go well beyond the rated voltage. If you don't have the right test equipment, even putting a DMM with "peak hold" (not min/max) in between EGC and neutral and keeping an eye on it can provide useful information.

What was in place before the retrofit, magnetic ballasts or electronic? The reason I ask is that magnetic ballasts are basically immune to fractional second exposure to neutral lift. It'd have to be exposed to over voltage condition long enough to burn out the coil or exposed to high enough over voltage to arc over.
Unless you substitute something else as a load, those ballasts are what is loading the circuit and without load there will be no change in neutral voltage if neutral is bad.
 

Flicker Index

Member
Location
Pac NW
Occupation
Lights
Unless you substitute something else as a load, those ballasts are what is loading the circuit and without load there will be no change in neutral voltage if neutral is bad.
He hasn't lost all of them yet... though. I meant that he should check before installing the NEW replacement.
 

Jchamos

Member
Location
Indianapolis
Occupation
Electrician
Utility company set a voltage logger last week and give me an answer by this Friday about their voltage 285v they said is pretty common
I’m wondering if they can somehow lowered
Or I need to get a transformer to correct and apply constant 277 or less to this crazy lights
 

Flicker Index

Member
Location
Pac NW
Occupation
Lights
I wouldn't expect the utility's logging to give you anything abnormal. They're checking for things that's just at the utility responsibility side of the deal.


If you hook up the 15W bulb's tip to L1, 150W bulb's tip to L2, bundle the "shell" ends together and hook it up to neutral, they'll both operate as normal. Draw it out. You have 3 wires going to the light socket. If you break the neutral, the 150W bulb will pretty much go out and 15W will get extremely bright or blow. The neutral break is usually not complete, but an intermittent loose connection at one of the interconnecting lug nuts in a box or at the panel lug. With just a slightly loose neutral, both bulbs will probably just remain lit, but the 15W bulb will "flash" when the 150W is flipped on. Such disturbance is only imposed downstream of the loose connection. If you hook up two 40W filament light bulbs in series and hook them up L-L to 240v, they'll light up just fine regardless of what the neutral is doing.

Is this an industrial facility with motors and stuff on 480v? If it's not neutral issue, there's some possibility that your new LED ballasts are poorly engineered and could not handle the normal surge from industrial equipment. When T8s were new, a lot of ballasts failed because of this, because of line conditions in real world that was not anticipated on the engineer's test bench. Looking at the photo of your failed LED ballast, it's obvious it's not a gradual overheating, but a catastrophic failure.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Update

voltage logger shows
285 to 291 Volts per phase from utility
Utility company is lowering the voltage 5% of the 285v
They're going to lower it to 270??
Unless they are doing this with XF taps it puts their single phase customers at 117
 
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Flicker Index

Member
Location
Pac NW
Occupation
Lights
Update

voltage logger shows
285 to 291 Volts per phase from utility
Utility company is lowering the voltage 5% of the 285v
That's within the acceptable range (+/- 5%) and not the cause unless your LED ballasts suck. Neutral related issues in the panel or boxes is much more likely, and data logging needs to happen near where the ballasts are getting fried.

Have a look at a T8 fluorescent ballast specifications as a reference:

"2.4 Ballast shall operate from 50/60 Hz input source of 120V or 277V with sustained variations of +/- 10% (voltage and frequency). IntelliVolt models shall operate from 50/60 Hz input source of 120V through 277V with sustained variations of +/- 10% (voltage and frequency)"

LED ballasts are expected to be able to handle the same. If they're not, stop selecting substandard materials.
 

tortuga

Senior Member
Location
(44.057116, -123.103394)
Occupation
field supervisor
I am with kwired's bad neutral theory I have troubleshooted this exact thing in parking lot lights that lost a neutral.

That's within the acceptable range (+/- 5%) and not the cause unless your LED ballasts suck. Neutral related issues in the panel or boxes is much
Hmmm I am not so use our North American voltage specs are strange, per ANSI C84-1 there it not much head room above 277.
291 L-N would be 508 L-L on the customer side of fully loaded transformer. As measured that is right on the line, a possible liability for the utility.
 

Flicker Index

Member
Location
Pac NW
Occupation
Lights
I am with kwired's bad neutral theory I have troubleshooted this exact thing in parking lot lights that lost a neutral.


Hmmm I am not so use our North American voltage specs are strange, per ANSI C84-1 there it not much head room above 277.
291 L-N would be 508 L-L on the customer side of fully loaded transformer. As measured that is right on the line, a possible liability for the utility.
https://www.pge.com/includes/docs/p...ergystatus/powerquality/voltage_tolerance.pdf
All you could ever wanted to know about voltage range. But 291 is a hair above, or right at the very edge of the sustained utility voltage limit.
Still, LED ballasts that can not handle +/- 10% sustained are inadequate ballasts.

Other than exceeding voltage limit (such as those caused by loose neutral), electronic ballasts are rather sensitive to surge and even the integral ballast on some disposable LED lamps have an MOV to protect its ballast from small line transients that can harm semiconductor parts. MOVs look similar to a capacitor, but they're not marked "C" on the board. https://www.edn.com/teardown-a19-led-bulb/ see figure 5.

Now, if you find a cooked MOV, that is often caused by over-voltage. So that's something to check on the fried LED ballast. A normal "surge failure don't usually cause the MOV to visibly cook.

Thread starter, you didn't post the other side of the failed board. Did you take pictures of the component side?
 
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