# Anybody ever seen this?



## lheblen (Aug 27, 2010)

I went


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## lheblen (Aug 27, 2010)

I went on service call that lights were flickering, get there thinking bad neutral likely.
Got 120 from poco outside. No prob there.
I go inside and get 190 on one leg and 50 or so on other.


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## lheblen (Aug 27, 2010)

Sorry, keep posting on accident before I'm done.
Anyway, when I turn off 1 circuit, voltages get closer to normal. When I turn off 3 specific ones, voltage in panel goes back to 120 to groung(neutral) on each leg.

If I turn them back on the lights in house get brighter but voltage spikes/ drops back to crazy numbers.
It only goes back to normal when those 3 specific breakers are turned off. All single pole 15s. A bedroom, a kitchen circuit and utility room.

It's s rental house. They've lived there a year and say it just started a couple weeks ago. I always get 240 leg to leg. Not sure what's up.


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## Bird dog (Oct 27, 2015)

Sounds like you do have a bad neutral. Did you check all your neutral connections from the main panel back to the service neutral back to the xfmr? Squirrels like to knaw through the overhead service neutral. If all that looks good call the POCO.


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## splatz (May 23, 2015)

That's exactly what happens when the service netural is floating. 

The L1-N circuits will all be the same voltage; 
the L2-N circuits will all be the same voltage, 
but not necessarily the same as the L1-N; 
the L1-N and L2-N voltages will add up to 240; 
the more heavily loaded leg will measure lower voltage; 
when the loads on the legs are balanced, L1-N and L2-N will both be normal, about 120V; 
things will start to blow as you screw around turning circuits on and off.


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## lheblen (Aug 27, 2010)

Should have said. I had poco come out. They said all good on their end.
I get 120,120,240 outside on line side of meter.
What I guess I didn't do is take a reading with those 3 circuits on.


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## Bird dog (Oct 27, 2015)

Do any of those ckts share a neutral? Are they all on one leg of the service? What is probably happening is when you lose the neutral connection the voltage divides by the resistance of the ckt which is why your voltages are off.


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## lheblen (Aug 27, 2010)

I suppose if the poco took a reading with no load that would happen huh??
Should I just turn eeerything on and put a load on it and call em back?
Thinking about it now, those probably were the only circuits (120v) in house that would have had a load on em (fridge, bedroom lights and the lights in the panel room)

I'll call em back out.
Makes more sense when a consider the load aspect.


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## splatz (May 23, 2015)

lheblen said:


> Should have said. I had poco come out. They said all good on their end.
> I get 120,120,240 outside on line side of meter.
> What I guess I didn't do is take a reading with those 3 circuits on.


It could be open or a bad connection anywhere from the terminal on their transformer to the panel. Around here, they lie all the time. They'll tighten a bad connection and say it was fine when they got there, or do all their checking from the cab of their truck, in their imagination.


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## lheblen (Aug 27, 2010)

They don't share a neutral I can tell. They each have their own in panel, but who knows, they could be tied together somewhere else. And yeah, all on same leg.


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## J F Go (Mar 1, 2014)

I had a problem like that once. I found that the bonding screw was laying at the bottom of the panel. Installed bonding screw and all was good.


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## 3DDesign (Oct 25, 2014)

Pull the meter = no load =120/120/240

With an Open Neutral, as the unbalanced load changes between L1 & L2, so does the voltage. By unbalanced I mean higher amperage on one of the legs.
Unbalanced load with open Neutral results in:
L1 + L2 = 240
L1 + Neutral = I've seen it as low as 67v
L2 + Neutral = I've seen it as high as 178v

L2 reads high voltage so you shut off all the breakers on L2 because appliances and equipment were destroyed. 
Now the high voltage flops to L1 and destroys everything else.


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## John M. (Oct 29, 2016)

Definitely a bad neutral. Get your voltages out of balance at the panel, then keep tracing it back. Panel, meter load, meter line, POCO at the weatherhead if overhead.


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## MechanicalDVR (Dec 29, 2007)

Pretty common here @lheblen!

There are many older threads on this same issue.


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## Bird dog (Oct 27, 2015)

MechanicalDVR said:


> Pretty common here @*lheblen*!
> 
> There are many older threads on this same issue.


 Google may be the easyist way to find them.
google "lost neutral" & "open neutral"


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## matt1124 (Aug 23, 2011)

splatz said:


> It could be open or a bad connection anywhere from the terminal on their transformer to the panel. Around here, they lie all the time. They'll tighten a bad connection and say it was fine when they got there, or do all their checking from the cab of their truck, in their imagination.


“That’s the cable company’s line”

That big heavy wire coming from that big gray trash can sized transformer, connected to one of the three lines on the very top of the pole, and attaching to the house here, connected to these melted down burndys, going into that weatherhead, through this pipe right here, and connecting to the electric meter, that’s the cable TV? 

“Yep, that’s not us. Call Cox cable, they’ll fix it for you”. 

Last time I was there, they still had the melted down burndy insulinks...


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## Bird dog (Oct 27, 2015)

matt1124 said:


> “That’s the cable company’s line”
> 
> That big heavy wire coming from that big gray trash can sized transformer, connected to one of the three lines on the very top of the pole, and attaching to the house here, connected to these melted down burndys, going into that weatherhead, through this pipe right here, and connecting to the electric meter, that’s the cable TV?
> 
> ...


Depending on the situation, I would call the POCO again & if that didn't resolve the issue, call the Public Service Commission (the god of their world). :surprise:


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## lheblen (Aug 27, 2010)

Called poco again. Met their guy out there. Bad splice at weatherhead. Guess seconds time is a charm.
Thanks for the help guys. I guess after the first time they came out I assumed they were right in saying their side was ok. Feel dumb for not catching on to the load (or lack of) messing with readings.


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## splatz (May 23, 2015)

lheblen said:


> Called poco again. Met their guy out there. Bad splice at weatherhead. Guess seconds time is a charm.
> Thanks for the help guys. I guess after the first time they came out I assumed they were right in saying their side was ok. Feel dumb for not catching on to the load (or lack of) messing with readings.


This kind of thing, it's only simple once you know the answer  

I think just about everyone is baffled the first time they see it if nobody told them about it. 

With the Edison three wire circuit, if you lose the neutral, your system turns into a big series-parallel circuit.


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## MDShunk (Jan 7, 2007)

There were a lot Square D panels that would develop this symptom, and the first one was a little tricky for me to find. The neutral lug is held on the bar with a torx screw inside the lug. You have to completely remove the set screw and neutral wire to access that screw. Fixed many a loose neutral that way. There are many brands attached that way, but I've only found it loose in that one brand myself.


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## readydave8 (Sep 20, 2009)

J F Go said:


> I had a problem like that once. I found that the bonding screw was laying at the bottom of the panel. Installed bonding screw and all was good.


got it working but I wonder if all was really good?


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## splatz (May 23, 2015)

J F Go said:


> I had a problem like that once. I found that the bonding screw was laying at the bottom of the panel. Installed bonding screw and all was good.





readydave8 said:


> got it working but I wonder if all was really good?


It depends was the bonding screw re-installed with a torque screwdriver set to the manufacturer's specified torque using a torque screwdriver with calibration traceable to NIST?


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## splatz (May 23, 2015)

I certainly agree that using a torque driver for terminal screws is over the top, and really makes it seem more precise an operation than it really is. Think about it, in a world where its fine to use the backstab push-in but we're worrying about the precise torque of the terminal screws, something's messed up. 

BUT, I have to say, I really kind of like just cranking it until the driver clicks rather than cranking and paying attention to whether I feel like it's tight enough. I think I am probably overtorquing things often. I think it might actually speed me up and avoid occasionally damaging things.


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## readydave8 (Sep 20, 2009)

splatz said:


> It depends was the bonding screw re-installed with a torque screwdriver set to the manufacturer's specified torque using a torque screwdriver with calibration traceable to NIST?


I meant that installing bonding screw should not have fixed defective neutral


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## splatz (May 23, 2015)

readydave8 said:


> I meant that installing bonding screw should not have fixed defective neutral


True, I didn't think of that, that might have just been giving the neutral the ground path back to the transformer!


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## eddy current (Feb 28, 2009)

readydave8 said:


> I meant that installing bonding screw should not have fixed defective neutral


I agree. If installing the bonding screw fixed it, then that tells you there is a problem with the neutral somewhere.


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