# Why 120V between ground and nuetral ?



## ddawg16 (Aug 15, 2011)

No...not normal....sounds like maybe the hot and neutral are swapped. Have you measured between hot and neut and hot and ground?


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## pfm (Mar 15, 2012)

yes I measured those too. hot and nuetral is 120v and hot and ground is 0. So those look ok, its just the gnd-nuetral thats troubling. No other issues as such everything's running fine around the house (or atleast seems to be!). I just happened to discover this by chance.


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## kbsparky (Sep 11, 2008)

You may have an open ground. Describe your panel boxes, how many you have, where they are located, and whether you have an outside disconnect, etc.

Can you test between one of those "ground" connections, and another grounded surface, such as a water faucet?


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## zappa (Nov 25, 2011)

Wow! With the voltages you are giving us it sounds like your ground is energized with 120 volts and open like kb said.

Be very careful with touching metal things until you can figure out what is going on.


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## Missouri Bound (Apr 9, 2011)

pfm said:


> yes I measured those too. hot and nuetral is 120v and hot and ground is 0. So those look ok, its just the gnd-nuetral thats troubling. No other issues as such everything's running fine around the house (or atleast seems to be!). I just happened to discover this by chance.


 .....AHEM....hot to ground should be 120v.....so it's NOT OK. You have an open ground somewhere.


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## SD515 (Aug 17, 2008)

pfm said:


> yes I measured those too. hot and nuetral is 120v and hot and ground is 0. So those look ok, its just the gnd-nuetral thats troubling.


Hot to ground should read ~120V, not zero.

Should be:
Hot to neutral ~120V
Hot to ground ~120V
Neutral to ground ~0V

Re-check the measurements, and check different circuits around the house. Also answer kbsparky's questions. You may have an open ground being energized.


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## dmxtothemax (Oct 26, 2010)

Missouri Bound said:


> .....AHEM. You have an open ground somewhere.


 Or the system is not bonded !


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## dmxtothemax (Oct 26, 2010)

pfm said:


> My house was built in 2002. I just happened to notice that most of the outlets in the home measure 120v between the ground and nuetral. Is this normal ? If not what could be causing this and what should I do to fix this ?
> Please advise.
> Thanks.


What did you check it with ?
some digital testers can give false readings !
Use a test lamp !
not just a digital multi meter !

If the system is bonded correctily there should be NO difference
in voltage between the neutral and earth.
Get your neutral and earths tested and fixed pronto !


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## pfm (Mar 15, 2012)

I used a DMM. I am so sorry but this is going to be embarassing...
Actually I was thinking "hot" but wrote "neutral". The longer of the two slots is nuetral and the shorter one is hot, right ? I mixed up between the two, so yes it is 120v between hot and neutral and 120v between hot and ground. It reads 0 between between neutral and ground.
And when a load is applied to hot and ground, the gfci does trip.
So then all is well ?


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## AllanJ (Nov 24, 2007)

pfm said:


> So then all is well ?


All is well -- for now. Hopefully you won't find other rude awakenings.

Yes, the "hot" is the smaller of the two slots on a receptacle, to the right if the ground hole is below.


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## hammerlane (Oct 6, 2011)

pfm said:


> The longer of the two slots is nuetral and the shorter one is hot, right ?


The hot conductor should be attached to the brass screw terminal of the receptacle. This would make the "shorter" slot on the receptacle hot.


Just remember "short girls are hot"-----> short blade of receptacle is hot


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## Jim Port (Sep 21, 2007)

The load should not be tripping the GFI. Does the GFI trip when you plug just that one thing in or with more than one?


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## mpoulton (Jul 23, 2009)

Jim Port said:


> The load should not be tripping the GFI. Does the GFI trip when you plug just that one thing in or with more than one?


He said a load from hot to GROUND trips it, which is normal.


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## AHJ (Mar 8, 2012)

swap the ungrounded conductor and grounded conductor at the panel, or identify the conductors at the junction point.


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## gregzoll (Dec 25, 2006)

Could this be a MWBC (Multi-Wire Branch Circuit), that something is a amiss in the wiring? OP, post a picture of your panel with the label showing model# and manufacturer, and if you wish a picture of the inside of the panel. I use this http://www.lowes.com/pd_292758-1270...br|0||p_product_qty_sales_dollar|1&facetInfo= for regular testing if needing voltage, or this http://www.lowes.com/pd_225727-1190...br|0||p_product_qty_sales_dollar|1&facetInfo= when needing to check for voltage after doing work on an outlet, or finding out if it is dead. The second is a lot easier for people that do not know how to read a meter, if you have a helper helping you out. There are some better ones of the second one, but it gives you an idea of what to have in your arsenal of testers. I have the meter, a non-contact tester, and a ac/dc probe tester, that I use.


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