Questions about diagnosing when using two legs to feed ballast (208 or 240)

[LouisianaApprentice]

Today I got to operate the bucket truck for the first time and got to wire up my first pole lights. I had a question involving a non functional light. So this is all the information I gathered so far today and was just gonna get some opinions and kind of seeing how u veterans would go about diagnosing efficiently. The pole lights are on a photocell with 4 different contactors and a time clock. The time clock is broken it sends power regardless of whether being off or on (I'm guessing the photocell is keeping contactors pulled in regardless of time clock idk though. I seem to have lost a neutral somewhere as after hooking up the ballast and getting readings I'm getting 108v on the common tap going in and 115 on the 208v tap. 15 volts between them. My first step tomorrow will be to disconnect power at the bottom of pole and check voltages but what do these symptoms point to. It's 208v with no neutral in the light just 2 legs.

 

[augie47]

First thought isi you have lost one phase possibly through a contactor....again possible the contactor is only breaking one leg and it's not pulled in..... You are reading phase 115 on one and "feedback" on the other.
If the lights are connected to 208 (240) concentrate on that and don't pay much detail to voltage to ground (neutral)

above all.keep in mind this advice is worth what you paid for it

 

[LouisianaApprentice]

First thought isi you have lost one phase possibly through a contactor....again possible the contactor is only breaking one leg and it's not pulled in..... You are reading phase 115 on one and "feedback" on the other.
If the lights are connected to 208 (240) concentrate on that and don't pay much detail to voltage to ground (neutral)

above all.keep in mind this advice is worth what you paid for it

Ok thanks I'll check that after the joints in the bottom of the pole. It's just seems weird to be in a contactor as this is the last light not burning. Thanks for your help and Insight yet again Augie.

 

[augie47]

If its all one circuit, I agree it would not be the contactor. I did not pick up on the one light burning but keep in mind unless you know for sure that other light may be on a different circuit. Its not unusual to have selected lights on one circuit for security.

 

[LouisianaApprentice]

If its all one circuit, I agree it would not be the contactor. I did not pick up on the one light burning but keep in mind unless you know for sure that other light may be on a different circuit. Its not unusual to have selected lights on one circuit for security.

Ok thank you that should be an easy thing to check as the majority of pole lights so far have been on a contactor with 6awg all the others are smaller gauge if I see a different size coming in I'll know that's most likely the reason. My coworker I'm his helper checked voltage and said something about not getting voltage on one leg but after I cleared a fault in one light he said he had it back maybe he just checked and saw the breaker that was tripping held and didn't check the contactor. They are on 3 pole contactors do u think it would be an acceptable fix to just move the non working leg over to the empty one and see if it works? Or should we just replace it.

 

[WarrMann]

I seem to have lost a neutral somewhere as after hooking up the ballast and getting readings I'm getting 108v on the common tap going in and 115 on the 208v tap. 15 volts between them. My first step tomorrow will be to disconnect power at the bottom of pole and check voltages but what do these symptoms point to. It's 208v with no neutral in the light just 2 legs.

Im a little confused by your description. Its unlikely you would see symptoms of a lost neutral on only one pole light branch circuit. Especially a 208v one.

Which wires are you testing voltage on?

You should have two power wires and a ground coming to the top of the pole. Those power wires should read 208 across them on your meter. Are these the wires you're testing?

If so, and you are getting strange voltages, than i think its like auggie said about a bad contact on the contactor. You said you have 4 contactors so there's a decent chance each pole could be fed individually. When you turn the power on tomorrow morning, take a few minutes to check the line and load side of every contact on all the contactors.

If you're checking for voltage THROUGH the ballast, BE CAREFUL. You should expect to see strange voltages if you're checking wires coming from the ballast transformer. This scenario would make me think you have just miswired the ballast kit. What type of lamp is the ballast for?

Im not a stickler for safety, but i probably wouldn't let you test a live circuit with a meter in a bucket truck just yet. I Don't mean that as a personal attack, but you're just getting started. You shouldn't have to worry about not shocking yourself while you're 25ft up in a bucket truck for the first couple dozen times. You can always check voltage safely at the base of the pole, and then ring out the non-live wires to see if they're good up to the top of the pole.

Fortunately LEDs are replacing HID lighting. Every time i replace a magnetic ballast i feel good knowing that one day soon ill replace my last one!

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[LouisianaApprentice]

Im a little confused by your description. Its unlikely you would see symptoms of a lost neutral on only one pole light branch circuit. Especially a 208v one.

Which wires are you testing voltage on?

You should have two power wires and a ground coming to the top of the pole. Those power wires should read 208 across them on your meter. Are these the wires you're testing?

If so, and you are getting strange voltages, than i think its like auggie said about a bad contact on the contactor. You said you have 4 contactors so there's a decent chance each pole could be fed individually. When you turn the power on tomorrow morning, take a few minutes to check the line and load side of every contact on all the contactors.

If you're checking for voltage THROUGH the ballast, BE CAREFUL. You should expect to see strange voltages if you're checking wires coming from the ballast transformer. This scenario would make me think you have just miswired the ballast kit. What type of lamp is the ballast for?

Im not a stickler for safety, but i probably wouldn't let you test a live circuit with a meter in a bucket truck just yet. I Don't mean that as a personal attack, but you're just getting started. You shouldn't have to worry about not shocking yourself while you're 25ft up in a bucket truck for the first couple dozen times. You can always check voltage safely at the base of the pole, and then ring out the non-live wires to see if they're good up to the top of the pole.

Fortunately LEDs are replacing HID lighting. Every time i replace a magnetic ballast i feel good knowing that one day soon ill replace my last one!

Sent from my SM-G950U using Tapatalk

Yeah my question about the neutrals was because I just don't know I don't have much experience and usually funny voltage was always a neutral...that was my bad. I'm just now getting some hands on with doing stuff myself 240 and 208 single phase don't need a neutral usually. I'll never be able to learn something if I don't take some form of risk but I did it as safely as possible. I tested voltage through the wire nuts on the two legs as they came into the light before the ballast. I went from leg to leg and got 15 volts leg to ground and got 108 on one and leg to ground on the other and got 115.

 

[LouisianaApprentice]

Yeah my question about the neutrals was because I just don't know I don't have much experience and usually funny voltage was always a neutral...that was my bad. I'm just now getting some hands on with doing stuff myself 240 and 208 single phase don't need a neutral usually. I'll never be able to learn something if I don't take some form of risk but I did it as safely as possible. I tested voltage through the wire nuts on the two legs as they came into the light before the ballast. I went from leg to leg and got 15 volts leg to ground and got 108 on one and leg to ground on the other and got 115.

I said myself but the whole time I had a 25yr in the trade electrician as a ground man walking me through it as I asked questions for each step. He showed me how to wire them up on the ground after he had already did a few with me earlier that Dad on a scissor lift at another job site. Don't worry they aren't sending me out there to mess with this stuff on my own they know I'm new.

 

[WarrMann]

As long as you're comfortable, have at it up there man. Your asking good questions.

From what you're saying, your voltages are actually pretty reasonable for a pole light far from the source. That's we upsize wires for voltage drop. You have pretty close to acceptable voltages to ground.

I think your problem is that both the power wires in your light are being fed from the same phase. That's why you don't have any voltage when you measure across them. Think about how you measure 208 volts in a panel, you touch two breakers that are stacked, not side to side. If you touched the side by side breakers, you wouldn't get any reading because you haven't completed a circuit.

I'll bet the guy who rigged up that photo cell/ time clock situation you described moved a wire at a contactor or breaker. Find the breaker controlling that pole and follow its wires



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[LouisianaApprentice]

As long as you're comfortable, have at it up there man. Your asking good questions.

From what you're saying, your voltages are actually pretty reasonable for a pole light far from the source. That's we upsize wires for voltage drop. You have pretty close to acceptable voltages to ground.

I think your problem is that both the power wires in your light are being fed from the same phase. That's why you don't have any voltage when you measure across them. Think about how you measure 208 volts in a panel, you touch two breakers that are stacked, not side to side. If you touched the side by side breakers, you wouldn't get any reading because you haven't completed a circuit.

I'll bet the guy who rigged up that photo cell/ time clock situation you described moved a wire at a contactor or breaker. Find the breaker controlling that pole and follow its wires



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I'll check that as well but it is at a church and the deacon said they worked before but you know how that goes.thanks you guys for the input. I've had a bad feeling on the back of my mind that maybe I wired it up wrong but this is how I wired it. My coworker checked voltage and said it was 208 and that was how the previous ballast was tapped as well. The one common was hooked to one leg then the other common to the white wire from the socket. The black coming in went to the 208v tap then the wire off the capacitor to the black on socket. Now that I'm thinking of it the only thing I'm worried about is the common do these two common leads matter I didn't see any specific labeling as to ballast common or reg common. Could that be my issue....now I'm starting to second guess myself on everything.

 

[mopowr steve]

Yes, the two commons belong on the same leg.

 

[LouisianaApprentice]

Ok I wired it right then didn't know if one common was specific. I'll repost tomorrow when we clear up the issue.

 

[sameguy]

Didn't read your whole story, just try to keep it simple when trouble shooting, don't move wires around on things that did work until you know whats what; and make a drawing of the before move.
So, pole base power, fuses- y/n,
Step back and look at the big picture (forest for the trees), what is the most likely way the piping is run, where is the last fixture, open it (the handhole) same color wire, is the connection tight, do you have power there,.

 

[rambojoe]

do not confuse a white in the fixture for what the voltage is. a 3 phase sytem could send a black and blue to one set of lights and a blue and red to another, giving weird readings on a particular hot leg. remember that the photo cell is probably on a separate circuit altogether. sooner or later the bucket truck will have a good stock of lamps, capacitors and ballasts to trouble shoot with- if not, use materials from a fixture you know that works. ask how to discharge a capacitors. these are just general tips to chew on, that's all. always ask and fully understand how to lock out all circuits before attempting to work on it.

p.s.- in addition to a photocell on the roof controlling a contactor, sometimes fixtures have their own photo cell which may or may not be disabled. you may find you need all 3 legs on that contactor...

 

[LouisianaApprentice]

It ended up being a federal Pacific double pole breaker not resetting all the way it would send power on one leg and funny voltage on the other. We reset it a few times and it worked again.

 

[LouisianaApprentice]

do not confuse a white in the fixture for what the voltage is. a 3 phase sytem could send a black and blue to one set of lights and a blue and red to another, giving weird readings on a particular hot leg. remember that the photo cell is probably on a separate circuit altogether. sooner or later the bucket truck will have a good stock of lamps, capacitors and ballasts to trouble shoot with- if not, use materials from a fixture you know that works. ask how to discharge a capacitors. these are just general tips to chew on, that's all. always ask and fully understand how to lock out all circuits before attempting to work on it.

p.s.- in addition to a photocell on the roof controlling a contactor, sometimes fixtures have their own photo cell which may or may not be disabled. you may find you need all 3 legs on that contactor...

Yeah I need to learn about capacitors lol I remember one time we were working on a large ac compressor for a school and I don't know if I hit a hot somewhere or shorted out the capacitor but I accidentally shorted against something and whatever that was it hurt like hell. 120 usually doesn't phase me when it happens even though I still respect it but geez lol do all capacitors generally have that much energy in them.

 

[rambojoe]

120 usually doesn't phase me when it happens even though I still respect it but geez lol do all capacitors generally have that much energy in them.

The day will come when you will never again suggest that "120v ect…." Then you will join the rest of the folks here that jump and yell every time you jump out of the truck and get a baby static shock when you touch the door... I was at a horrible realtor office with new carpet the other day- goodness, I yelled some swear words every single time I grabbed a door knob. Then they all look at you like you are some kind of pansy. And that is just fine....

 

[WarrMann]

The day will come when you will never again suggest that "120v ect…." .

So true. I've had so many 120 shocks that's its hard to differentiate betweem them, and just accidentally poking myself with the cut end of a zip tie. Anytime i feel something remotely close to a shock while i'm working now, my arms do some sort of crazy move like those tall dancing blow up things the car dealerships have out front.

Worst i ever got it was up in a ceiling grid. Some asshole left a hot wire just hanging. I popped my head through the open tile, and something made that lose wire shift and hit me in the back of the neck. The shock hurt like hell, but mostly i was traumatized. I told them i wouldn't work in the office till i could shut down the whole space, they agreed and paid for it to be done after hours.

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[LouisianaApprentice]

So true. I've had so many 120 shocks that's its hard to differentiate betweem them, and just accidentally poking myself with the cut end of a zip tie. Anytime i feel something remotely close to a shock while i'm working now, my arms do some sort of crazy move like those tall dancing blow up things the car dealerships have out front.

Worst i ever got it was up in a ceiling grid. Some asshole left a hot wire just hanging. I popped my head through the open tile, and something made that lose wire shift and hit me in the back of the neck. The shock hurt like hell, but mostly i was traumatized. I told them i wouldn't work in the office till i could shut down the whole space, they agreed and paid for it to be done after hours.

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Lmao yeah I jump Everytime too now my worst 120 volt shock was in a cieling grid as well it was when I was like 4 month in to electrical work and I was replacing 2x4 layins. I disconnected one and it was an emergency lighting circuit and I didn't realize and the tail fell on my arm and i started doing a fire ant dance lol. It kept bouncing on and off of me as I was trying to get free from that energized metal hole lmao it never tripped the breaker. There's some scary stuff contractors make u do as a helper I've had to do everything from drive an f550 bucket truck with the stopping distance of 2 parking lots to cut vines out of transformers on high line poles (power was out from a storm and I think the Jack's were pulled) that scared the piss out of me as well in the bucket truck I moved a Vine and something hissed I didn't know if I was gonna get blown up or if a raccoon or snake was about to hop out of that transformer and maul me lol. While I was cutting all those green vines off you could see where the vines were burnt up where they grew between two legs or where they were going to ground. It's pretty scary when u don't know nothing.

 

[Adamjamma]

I know this may have nothing to do with the OPs question in a way but... with many of us now pulling two neutrals because of the gfci breakers, does this mean we connect the two neutrals to the neutral slot on a 240v 4 wire outlet? Or do we leave one loose? Would it matter?
What if we did a 240 outlet then did the separate legs as 120 outlets? I have seen this done in a factory before... tied breaker to 2 240 outlets then to several 120 outlets... but is it legal? Is It safe?