# 480v single phase ballast smoked



## Chrisibew440 (Sep 13, 2013)

Is there a schematic stuck to the ballast?


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## Chrisibew440 (Sep 13, 2013)

I just looked at the schematic and it seems you have it right.
Yet I think you need to take second phase to all commons because the bulb is in parallel with that connection.


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## HARRY304E (Sep 15, 2010)

MattJ said:


> I have a pole light, it's got 2 fixtures each is a single pole 480v. 480v phase to phase, 277 phase to ground(I checked them both). I replaced both ballasts, capacitors, and lamps with sylvania's m400 super kit. ReWired as follows: 480tap from ballast to hot leg 1. Com wire to hot leg 2. Other com wire to lamp, 1 capacitor wire is prewired to ballast, and other cap wire to lamp socket. Fired up, and smoked one ballast. Other fixture turned on. Replaced the smoked ballast thinking "ok, random bad ballast" turned on power, then, the previously working ballasts smoked, and original smoked ballast now worked... Gotta go back tomorrow and troubleshoot it, but any ideas? This is a parking lot light pole and first time I've encountered this.


When you change those ballasts they are pre-wired in the box.

When you remove the ballast and the capacitors starters, you should only have the wires for the feed and the lamp socket.

install the whole kit and splice them to whats left in the light.

There is no need to take apart splices on the new ballast kit.

Make sure the lamps match the ANSI rating on the ballast kit.

Welcome to the forum.:thumbsup:


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## Holop (Sep 8, 2008)

You said single phase but you measured both wires to the ground and got 277v on each and 480v between them? Sounds like its two phase. 

Make sure there is no shortage check if the coil have any contact with fixture or if you pinched any of the wires when tightened it. 

You mentioned its a super kit does that mean its a pulse start or probe what's so special about that super kit? 

You should try installing and testing them separately so both are not installed at the same time because there might be wiring issue.


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## MDShunk (Jan 7, 2007)

Holop said:


> You said single phase but you measured both wires to the ground and got 277v on each and 480v between them? Sounds like its two phase.


:laughing:


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## Holop (Sep 8, 2008)

MDShunk said:


> :laughing:


What am I missing?


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## MDShunk (Jan 7, 2007)

Holop said:


> What am I missing?


An electrical education?

You do know that a two-phase system only exists in 3 very small and distinct geographic locations in the whole of North America, don't you?


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## Holop (Sep 8, 2008)

Two phase are everywhere how do you get a 240v then? 120v from each phase isn't 240?


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## 1.21gigawatts (Jun 22, 2013)

Holop said:


> Two phase are everywhere how do you get a 240v then? 120v from each phase isn't 240?





On the most common wye connected system 120/208. Or 277/480

1-ph 120. 1-ph 277
1-ph 208. 1-ph 480
3-ph 208. 3-ph 480

2 phase utilizes 4 wires and is rare bird. When you speak of two hots, it is not a 2 phase connection. Same applies to single phase residential services.


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## TOOL_5150 (Aug 27, 2007)

rollin and trollin


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## Holop (Sep 8, 2008)

1.21gigawatts said:


> On the most common wye connected system 120/208. Or 277/480 1-ph 120. 1-ph 277 1-ph 208. 1-ph 480 3-ph 208. 3-ph 480 2 phase utilizes 4 wires and is rare bird. When you speak of two hots, it is not a 2 phase connection. Same applies to single phase residential services.


Thanks for explanation. Have to learn somewhere.


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## Southeast Power (Jan 18, 2009)

MDShunk said:


> :laughing:


Two outta three, still single phase. Three out of three, then you really got something.


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## Southeast Power (Jan 18, 2009)

MattJ said:


> I have a pole light, it's got 2 fixtures each is a single pole 480v. 480v phase to phase, 277 phase to ground(I checked them both). I replaced both ballasts, capacitors, and lamps with sylvania's m400 super kit. ReWired as follows: 480tap from ballast to hot leg 1. Com wire to hot leg 2. Other com wire to lamp, 1 capacitor wire is prewired to ballast, and other cap wire to lamp socket. Fired up, and smoked one ballast. Other fixture turned on. Replaced the smoked ballast thinking "ok, random bad ballast" turned on power, then, the previously working ballasts smoked, and original smoked ballast now worked... Gotta go back tomorrow and troubleshoot it, but any ideas? This is a parking lot light pole and first time I've encountered this.


So, when you said "480tap" I am just assuming that it has 5 taps. Did it come setup for straight 480 or did you have to "select" a tap? If so, and I really hate to ask this, what did you did to the remaining taps if anything?

I have been doing a bit of lighting maintenance lately and have found that finding a smoked ballast is a rare thing, 10 out of 10 get a new lamp, 1/2 of those get a new capacitor, maybe one in 20 have a bad ballast.

You should put a fuse in the circuit for one thing, next, I would suspect a short between the load side of the ballast and the socket.


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## MattJ (May 7, 2014)

Thanks for the input all, i tested for shorts between conductors as well as lamp socket all was good. Second go around I changed out one at a time and applied power after ballast hook up, then after lamp install, then turned on again after I closed up ballast housing. Only thing I could conclude was faulty ballasts, or maybe the retrofit ballast was shorting to the housing. Either way, second go around was successful. The only change was my install method. Thanks again.


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## bnuzzi27 (Jun 20, 2014)

Holop said:


> You said single phase but you measured both wires to the ground and got 277v on each and 480v between them? Sounds like its two phase.
> 
> Make sure there is no shortage check if the coil have any contact with fixture or if you pinched any of the wires when tightened it.
> 
> ...


There isn't any such thing as 2 phase. Its either single phase or three phase. Single phase is 2 separate phases. Single pole is one of the 2 phases in a single phase electrical system.


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