# Ground to Neutral Resistance



## macmikeman (Jan 23, 2007)

Casper the friendly ghost voltage. Just use a buzzer continuity tester next time.


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## ~48~ (Jul 24, 2016)

I think what he's asking is why the resistance readings showed up at all.


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## dmxtothemax (Jun 15, 2010)

lynes.nathan said:


> when I test with my Ideal Sure Test 61-165 it all tests ok. Any ideas what would cause this?



Maybe the Ideal Sure Test uses a higher test current ?


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## Sparkysquared (Jul 28, 2016)

Could it be induction on other loomex/romex ran near by?

In theory, we should be reading 0 ohms. If you had an induced voltage on the lines from other wires, could you potentially measure the loss on the distance from the neutral bonded to the panel? 

That's my best guess. Staying tuned for someone else to chime in.

Sent from my SM-G900W8 using Tapatalk


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## Helmut (May 7, 2014)

~48~ said:


> I think what he's asking is why the resistance readings showed up at all.


Bad meter leads, low battery...


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## MechanicalDVR (Dec 29, 2007)

Using a good meter I don't think I've ever seen 0 ohms.


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## macmikeman (Jan 23, 2007)

MechanicalDVR said:


> Using a good meter I don't think I've ever seen 0 ohms.


Every meter will have internal resistance. Every meter measuring resistance will have some sort of power supply method which will affect the end result reading. Once you start reaching higher ohms it won't matter much to the overall reading.


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## just the cowboy (Sep 4, 2013)

*Switch to voltage*

Switch your meter to volts and see if you have voltage, sure sounds like some low voltage induced in the lines.


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## lynes.nathan (Oct 24, 2012)

just the cowboy said:


> Switch your meter to volts and see if you have voltage, sure sounds like some low voltage induced in the lines.



I measured the voltage and I am getting 300 mV from neutral to ground.
This measurement was taken with the fluke 87V and the stray voltage adaptor. I am thinking this voltage is screwing up the resistance readings.


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## JRaef (Mar 23, 2009)

Neutral is a "current carrying conductor" and therefore required to be insulated. it is REFERENCED to ground, but the only place it should be at the exact same potential is at the bonding point. After that, because the Neutral wire is insulated, there will always be a resistance that you can measure when comparing it to ground at the receptacle, you are measuring the resistance OF the Neutral wire itself back to the bonding point, because from there on, it is an insulated conductor. Bottom line, measuring the resistance from G-N at a receptacle is interesting, but otherwise pointless information, unless maybe by comparison if you are LOOKING for a loose or disconnected N somewhere in the circuit.

The "phantom" voltages you are reading are likely induced from wires that are in close proximity to other live wires. The live wires have magnetic fields that expand and collapse around them 120 times per second and if another conductor is in those fields, it will have a voltage induced upon it. That's how a transformer and an AC induction motor work! In the case of parallel conductors, there is no real "turns ratio" to amplify anything, so the voltage potential it induces is very weak. Some meters will filter that out and not bother showing it to you, some won't. If you used something with a high impedance, like a Wiggy, it wouldn't ever register.


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## emtnut (Mar 1, 2015)

lynes.nathan said:


> I was replacing some receptacles in a apartment building and after I was done I decided to check the ground to neutral resistance at the receptacle. With the power still off and all loads not connected to the receptacles, the resistance value fluctuated like crazy. It would go from 30 ohms to 0 ohms and all in between. I checked another receptacle on another circuit and it did the same thing. I experienced this fluctuating resistance value on a fluke 87V meter and on a Klein tools MM1000. However, when I test with my Ideal Sure Test 61-165 it all tests ok. Any ideas what would cause this?


The Ideal meter is not measuring resistance, it is basically a load test.
You can't measure resistance, unless the circuit is isolated. Any current/voltage will screw up the multimeter's reading.

Even though the breaker was off, you could still be picking up stray current from the neutral in the panel (as DMX said) , or picking up a ghost voltage (as Mac said). Either of which will mess up your resistance reading.


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## PlugsAndLights (Jan 19, 2016)

JRaef said:


> Neutral is a "current carrying conductor" and therefore required to be insulated. it is REFERENCED to ground, but the only place it should be at the exact same potential is at the bonding point. After that, because the Neutral wire is insulated, there will always be a resistance that you can measure when comparing it to ground at the receptacle, you are measuring the resistance OF the Neutral wire itself back to the bonding point, because from there on, it is an insulated conductor. Bottom line, measuring the resistance from G-N at a receptacle is interesting, but otherwise pointless information, unless maybe by comparison if you are LOOKING for a loose or disconnected N somewhere in the circuit.
> 
> The "phantom" voltages you are reading are likely induced from wires that are in close proximity to other live wires. The live wires have magnetic fields that expand and collapse around them 120 times per second and if another conductor is in those fields, it will have a voltage induced upon it. That's how a transformer and an AC induction motor work! In the case of parallel conductors, there is no real "turns ratio" to amplify anything, so the voltage potential it induces is very weak. Some meters will filter that out and not bother showing it to you, some won't. If you used something with a high impedance, like a Wiggy, it wouldn't ever register.


Is this what you meant to say? 
P&L


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## emtnut (Mar 1, 2015)

JRaef said:


> After that, because the Neutral wire is insulated, there will always be a resistance that you can measure when comparing it to ground at the receptacle, you are measuring the resistance OF the Neutral wire itself back to the bonding point, because from there on, it is an insulated conductor. Bottom line, measuring the resistance from G-N at a receptacle is interesting, but otherwise pointless information, unless maybe by comparison if you are LOOKING for a loose or disconnected N somewhere in the circuit.


The Ideal meter has a 'bootleg' ground function.
It can detect a bootleg if there is extremely low resistance between neutral and ground.
I agree though, useless in a new installation .... probably useless in older installs too, cause you already know there is a bootleg ground somewhere !! :blink:


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## Brain John (Jul 15, 2016)

Sparkysquared said:


> Could it be induction on other loomex/romex ran near by?
> 
> I*n theory, we should be reading 0 ohms.* If you had an induced voltage on the lines from other wires, could you potentially measure the loss on the distance from the neutral bonded to the panel?
> 
> ...


In theory or not you will never see ZERO "0" ohms.

An accurate reading requires a DLRO/Ductor/Micro-ohm meter or a two point ground tester. Cost 2200.00-5400.00


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## Sparkysquared (Jul 28, 2016)

Brain John said:


> In theory or not you will never see ZERO "0" ohms.
> 
> An accurate reading requires a DLRO/Ductor/Micro-ohm meter or a two point ground tester. Cost 2200.00-5400.00


I've now learned that people here are very literal. I'll stand corrected on this one. [emoji106] 

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## Brain John (Jul 15, 2016)

Sparkysquared said:


> I've now learned that people here are very literal. I'll stand corrected on this one. [emoji106]
> 
> Sent from my SM-G900W8 using Tapatalk




It makes a serious difference.

The further you get from the neutral to ground bond and the higher the load and taking into account the conductor size the higher the neutral to ground voltage due to voltage drop in the circuit will be.


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## Majewski (Jan 8, 2016)

Nathan I don't know if you looked but there are a few decent threads over the last 5 years in this forum somewhat related to this topic.


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## ~48~ (Jul 24, 2016)

Here's an interesting conversation I've found

http://www.electriciantalk.com/f2/solenoid-tester-11738/


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## lynes.nathan (Oct 24, 2012)

I figured the voltage reading had to be induction from adjacent wires. This voltage is probably causing the strange resistance readings.


The wiring in this building is quite old (60 plus years). If you bend it to much the insulation cracks and it exposes copper. I wanted to measure the resistance between neutral and ground to verify that I didn't create another neutral to ground bond at the receptacle. However in the end my ideal 61-165 didn't show a boot leg ground so I take it everything is ok.


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## JRaef (Mar 23, 2009)

PlugsAndLights said:


> Is this what you meant to say?
> P&L


No... no it's not. 

We need an emoji for brain fart.


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