# V LG vs V NG



## poosri (Apr 15, 2015)

If either of these values are zero, what does that mean?


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## seandapaul24 (Apr 15, 2015)

Seriously?


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## dayrongarcia (Apr 15, 2015)

is that Voltage Line to Ground and Voltage Neutral to Ground?


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## louis077 (Apr 16, 2015)




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## cupojoe PE PMP (Apr 22, 2015)

poosri said:


> If either of these values are zero, what does that mean?




Not sure if this is a real question, but in the case you are troubleshooting an issue, I recommend you hire an qualified electrician and/or engineer to perform this work for you. If you are testing something, either your meter is not being used correctly or you potentially (pun intended) have a dangerous situation.

Voltage Line to Ground - Means you have no voltage (or possibly your ground is floating at line voltage). If you think you should have electricity, but your meter is reading zero: Best case you are probably not using your meter correctly, Worst Case, you have a very dangerous situation.

Voltage Line to Neutral - This isn't usually analyzed on paper, in a perfect world this should always be zero (though there are exceptions based on how perfect your imaginary world is). If you are getting this meter reading it means things are probably okay (though not guaranteed). If there is a potential here, this is means something probably isn't right (again not guaranteed). But again, you may not be using your meter correctly.


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## Ship Wreck PE (Apr 22, 2015)

Neutral to ground should be 0. The neutral and ground are connected together at the main bonding jumper.

Line to ground should be 120 or 277 if you are working in one of these most common systems.


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## knight1fox3 (Apr 22, 2015)

Ship Wreck PE said:


> The neutral and ground are connected together at the main bonding jumper.


This is not always the case, just FYI. Especially for some older 3-phase plant/facility distribution systems.


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## iwire (Apr 22, 2015)

knight1fox3 said:


> Ship Wreck PE said:
> 
> 
> > The neutral and ground are connected together at the main bonding jumper.
> ...


Depending where you measured it



> At service equipment, the voltage difference between the neutral conductor and the service equipment case will be 0 volts.
> 
> At panelboards, the voltage difference between the neutral conductor and the equipment grounding conductor (panelboard case) will be equal to the voltage drop of the feeder neutral conductor, which is 3 volts.
> 
> At branch circuits, the voltage difference between the neutral conductor and the equipment ground (ground contacts of the receptacle) will be equal to the voltage drop of the feeder and branch circuit neutral conductors, which is 4.5 volts (3 volts feeder and 1.5 volts branch circuit).






or you have fault


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## cupojoe PE PMP (Apr 23, 2015)

knight1fox3 said:


> Ship Wreck PE said:
> 
> 
> > The neutral and ground are connected together at the main bonding jumper.
> ...




Also it is connected at a lot of light switches in residential...it's not right, but some "weekend electricians" just connect all the grounds and neutrals together (there are plenty of regular electricians too).


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