# safe to change light ballasts with switch off?



## shortcut

Changing a school worth of defective led light ballasts. So if I turn the switch off for the classroom is it completely safe to work on? Say I'm working a classroom on circuit 2, multiple classes are on circuit 2, and circuits 4 / 6 carrying loads as well. Even though the hot is off for that class, is there danger with the neutral from all the other energized stuff on the circuits?


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## Wirenuting

Yes there can be


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## FrunkSlammer

Neutral isn't usually even neutral, it's the return path of the circuit. So you can consider it the back side of the hot conductor. 

So yes.. the white can zap you.


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## drspec

shortcut said:


> Changing a school worth of defective led light ballasts. So if I turn the switch off for the classroom is it completely safe to work on? Say I'm working a classroom on circuit 2, multiple classes are on circuit 2, and circuits 4 / 6 carrying loads as well. Even though the hot is off for that class, is there danger with the neutral from all the other energized stuff on the circuits?


 
there should be a ballast disconnect installed


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## papaotis

put a wire nut on it while you work. that makes it safer. oh, and dont stick your tongue on it!


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## ponyboy

If each fixture has it's own whip and no neutrals feed through the fixture you'll be fine


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## Big John

If you're not opening current-carrying neutrals and your LOTO'd switch is the only source of power, you're fine.

Beware of electronic switching. I once got my ass lit up by depending on that to completely isolate me; there is often let-through current.


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## Michigan Master

While you're doing this job you should install disconnecting means for the ballasts.

http://www.tnb.com/pubint/docs/luminaire/TnB_Luminaire_WhtPaper.pdf


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## daveEM

I do them hot all the time. Be careful. 

I just clip the hot and install a luminaire disconnect first. I use the existing wire from the bad ballast to do this and just check the existing wire nuts for tightness. I don't undo the connection.


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## mk2munky

It's really not great practice to just do work by turning off the switch. I think our local had an apprentice die that way. If someone comes into the area and turns on the switch while you're working on the circuit, look out! As others said, most fixtures nowadays come with disconnects, but otherwise you could add one to make them code compliant. I don't believe neutrals are to be shared anymore either, however....

The best practice is probably to shut the whole circuit down and lock it out.


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## don_resqcapt19

I liked the old fixtures that used single pin lamps, and interrupting lamp holders. removing the lamps disconnected the power to the ballast. You did have to be careful as not all fixtures disconnected both the hot and the neutral, and the ones that only interrupted one side sometimes opened the neutral and not the hot. Was really nice to safely change ballasts without shutting down a bunch of lights.


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## RGH

Note: EC&M ran an article several years ago about the most common place for shock injuries in out trade.......it was changing ballast..yep I will try to dig it up in their web site.....shock and then of coarse the fall from the ladder as the final icing on the hurt cake.


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## RGH

Here is one:

If a lighting ballast fails, do you change it out hot? That's a fairly common practice, but you can get electrocuted by 277V just as surely as from a higher voltage. If you're on a ladder, the fall might kill you even if you survive the shock. When you lockout and tagout the breaker supplying that ballast, you inconvenience people who work in that area. Nevertheless, unwiring the ballast while hot puts you at risk.
If you really must change ballasts while others are working in the area (instead of between shifts), you can shrink the time window if you first wire the ballasts with listed quick disconnects. In fact, you can find quick disconnects made specifically for luminaires. These special connectors prevent reverse wiring and are finger-safe. Consequently, you can unplug the ballast just as safely as if you were unplugging a floor fan. You could convert to the quick disconnect configuration case by case as ballasts need replacement. However, consider scheduling a mass conversion during a normal plant (or office) shutdown, in a manner similar to mass re-lamping.
_Caution_: This quick disconnects don't eliminate ladder safety requirements. Rope off the area around the ladder. You don't want to drop a heavy tool onto someone's unprotected head. Nor do you don't want someone knocking your ladder over while you're on it.


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## chicken steve

The prob is, nobody wants to be in the dark long enough for us to do our work



~CS~


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## sparky970

Is there a compelling reason the circuit can't be turned off and locked out?


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## smartblonde

Work it hot. Who cares?


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## sparky970

smartblonde said:


> work it hot. Who cares?



osha


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## smartblonde

sparky970 said:


> osha


Im an sp. Screw osha


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## union347sparky

smartblonde said:


> Work it hot. Who cares?



Your family when you don't come home.


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## sparky970

smartblonde said:


> Im an sp. Screw osha


Sp? What does that mean? The sites I work at would issue a lifetime ban for doing that too. We can't even take the cover off a panel without shutting it down. All it takes is a little planning.


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## ponyboy

sparky970 said:


> Sp? What does that mean? The sites I work at would issue a lifetime ban for doing that too. We can't even take the cover off a panel without shutting it down. All it takes is a little planning.


We are worlds apart from what a lot of other people think of sop


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## drumnut08

smartblonde said:


> Im an sp. Screw osha


 welcome back Cletis ! I like what you've done with your hair , lol !


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## MTW

smartblonde said:


> Im an sp. Screw osha


Hi McClary.


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## NacBooster29

Led lamps don't have ballasts. They have led drivers. Typical 4' led lamps have the drivers contained in the lamp. The tombstones are wired directly to line voltage bypassing any ballast


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## Michigan Master

smartblonde said:


> Im an sp. Screw osha


Smart blonde, yeah right...


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## chicken steve

Over 1/4 century ago we were told to change out a lotta ancient F69T12 277V ballasts live over _working _production on 12' ladders 

I shorted a hot to ground, the arc took out the serving panel's main 

Being darker than the ace of spades resulted in the screaming of workers not seeing the machinery still running, etc etc 

We were summarily _shunned ,flogged , publicly degraded and dismissed...._

By the very  management who _told us _to do it live


~CS~


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## Techne

ponyboy said:


> We are worlds apart from what a lot of other people think of sop





chicken steve said:


> Over 1/4 century ago we were told to change out a lotta ancient F69T12 277V ballasts live over _working _production on 12' ladders
> 
> I shorted a hot to ground, the arc took out the serving panel's main
> 
> Being darker than the ace of spades resulted in the screaming of workers not seeing the machinery still running, etc etc
> 
> We were summarily _shunned ,flogged , publicly degraded and dismissed...._
> 
> By the very  management who _told us _to do it live


Seems to be the case all too often these days. Most common, "hypothetical" scenario.


*Proposed Task (customer): *Changing ballasts in linear strip 347V T8 fixtures (of course, no ballast disconnects) in a grocery store_ live_, _during business hours_, _off the top of a 12' aluminum ladder_, _without isolating the area from customer traffic_. 


*Recommendation (from J-Man and apprentice):* This is a potentially dangerous task to both the worker and the public, and would leave the supervisor, the contractor, and the store with their collective beans tightly in a noose - or worse - should something bad occur. Ideally we would like to do this after-hours for reasons of safety and efficiency (ballasts per hour, negotiating aisle and display space with customers) and from a lift or mobile scaffold (also for reasons of efficiency and also safety @ heights), where we would be able to safely LOTO the circuit without risk of re-energizing accidentally by a worker. 


*Common responses (from customer/store managers):*

- "We've always had it done this way."

- "We can't afford to pay you guys OT to come in after-hours."

- "We can't afford to have a lift sitting around all the time."

- "A lift rental costs _WHAT_??"

- "We'll just start looking for another electrical company to come in if you don't want to."​

Race to the bottom, boys, race to the bottom. Most times, the boss said do it, and the guys did.


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## sparky970

We had a to change lamps and disconnect occ sensors on 625 fixtures. They were all 277v plug in. 2 weeks before we started, there was a fatality at one of their other mills from somebody getting hung up on 277v lighting. They made us wear 500v gloves to unplug them.


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## Michigan Master

sparky970 said:


> We had a to change lamps and disconnect occ sensors on 625 fixtures. They were all 277v plug in. 2 weeks before we started, there was a fatality at one of their other mills from somebody getting hung up on 277v lighting. They made us wear 500v gloves to unplug them.


Any details on how the fatality occurred? Surely it wasn't by simply unplugging a fixture...?


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## retiredsparktech

papaotis said:


> put a wire nut on it while you work. that makes it safer. oh, and dont stick your tongue on it!


We had one area of the plant, where the lighting was 240 volts, derived from a three phase corner grounded delta system. The QO panel had both single and two pole breakers, for the lighting. I worked for twenty years as an electrician, there and don't know, who came up with that brilliant idea.
The being said, I always locked out the circuit, when replacing ballasts.
The rest of the plant and office, where the lighting circuits were 120 volts, I always changed the ballast, hot. I just capped off the hot wire, while working.


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## Mshea

smartblonde said:


> Work it hot. Who cares?


Your name is Smart blonde but this is adumbass answer?
Because hot work is dangerous. Because in many places it is illegal and often is the cause of death on death certificates for a starter.
I am not saying I have never worked hot but I have to ask why did I when I did. I know switching off the power might have saved me a few tar spots on my face  .


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## fistofbolts

who knows who wired up the syatem before and who has come in added to etc. while doing some demo work, we had a panel shot off and still were getting plenty of readings on some neutrals. I wouldnt trust it with your life.


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## five.five-six

I treat every gun as if it is loaded and every wire as if it was hot until I verify for myself that it is not. 

The worst zap I ever had, excluding 277, was from a lose neutral that served fluorescent ballasts.


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## chicken steve

Mshea said:


> Your name is Smart blonde but this is adumbass answer?
> Because hot work is dangerous. Because in many places it is illegal and often is the cause of death on death certificates for a starter.


Blondie opines on the system, vs. those of us_ subjucated_ to it Mshea

The safety cabal wittles a notch in their belt every time on of us 'effs up

And if we buy it, shills like Joe T post our fried corpses to grease that ride

therearenoroadshere _nailed_ it

~CS~


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## chicken steve

five.five-six said:


> I treat every gun as if it is loaded and every wire as if it was hot until I verify for myself that it is not.
> 
> The worst zap I ever had, excluding 277, was from a lose neutral that served fluorescent ballasts.


I was blinded once...................bad trip......



~CS~


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## sparky970

Michigan Master said:


> Any details on how the fatality occurred? Surely it wasn't by simply unplugging a fixture...?


I really don't remember the details. We did what the customer asked. Made money, customer was happy, and no incidents. What else do you need?


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## Michigan Master

sparky970 said:


> I really don't remember the details. We did what the customer asked. Made money, customer was happy, and no incidents. What else do you need?


Addressing the root cause is the best way to avoid reoccurrence and knee-jerk corrective actions.


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## Bipeflier

It is over 50 volts, wear your class 00 insulated gloves and leather protectors.

Your family will thank you.


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## five.five-six

Bipeflier said:


> It is over 50 volts, wear your class 00 insulated gloves and leather protectors.
> 
> Your family will thank you.


My family doesn't like me all that much and I have way too much life insurance.


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## ponyboy

five.five-six said:


> My family doesn't like me all that much and I have way too much life insurance.


Everyone's plotting against me as well. My dog likes me though


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