Voltage testing

[The electron man]

I know to test my ungrounded conductors ,I can test
Line to Line
Line to ground
Or
Line to neutral

But how do I test for voltage on the ground ?

 

[HEYDOG]

I know to test my ungrounded conductors ,I can test
Line to Line
Line to ground
Or
Line to neutral

But how do I test for voltage on the ground ?

You could start off with a non contact tester!

 

[Sea Nile]

voltage on ground, usually reads 0. So testing it won't give very helpful results.
But you can test current.

 

[jim dungar]

voltage on ground, usually reads 0. So testing it won't give very helpful results.
But you can test current.

Ideally the neutral to ground may be 0V, but not always so this should be a normal voltage test.

If the neutral to ground bound is compromised it is possible to measure a N-G voltage.
If there is significant current flowing on the neutral the resultant voltage drop may be measured.

 

[The electron man]

You could start off with a non contact tester!

I ment with a multimeter

 

[The electron man]

voltage on ground, usually reads 0. So testing it won't give very helpful results.
But you can test current.

I just want to test for potential

 

[The electron man]

Ideally the neutral to ground may be 0V, but not always so this should be a normal voltage test.

If the neutral to ground bound is compromised it is possible to measure a N-G voltage.
If there is significant current flowing on the neutral the resultant voltage drop may be measured.

If the bonding is not compromised , I can't test n-g with a multimeter ???

 

[don_resqcapt19]

If the bonding is not compromised , I can't test n-g with a multimeter ???

On a properly installed system, when you test for voltage between the neutral and the ground, an you see voltage, you are seeing the voltage drop on the neutral between that point on the circuit and the location of the main bonding jumper or system bonding jumper in the case of a SDS

 

[jim dungar]

If the bonding is not compromised , I can't test n-g with a multimeter ???

Yes you can.
See Don's reply.

 

[The electron man]

On a properly installed system, when you test for voltage between the neutral and the ground, an you see voltage, you are seeing the voltage drop on the neutral between that point on the circuit and the location of the main bonding jumper or system bonding jumper in the case of a SDS

What's sds

 

[don_resqcapt19]

What's sds

Separately derived system, the most common of which is the secondary side of a transformer.

 

[Sea Nile]

If the bonding is not compromised , I can't test n-g with a multimeter ???

You can turn off the main and test continuity between neutral and ground

 

[LarryFine]

I know to test my ungrounded conductors ,I can test
Line to Line
Line to ground
Or
Line to neutral

But how do I test for voltage on the ground ?

In your first three examples, you acknowledge that voltage is measured between two points.

To what point would you want to measure voltage on ground against?

 

[ptonsparky]

Consider that EG conductor as an extension of your meter lead under normal conditions. Normally there is no current flowing on the EG.

 

[Strathead]

I know to test my ungrounded conductors ,I can test
Line to Line
Line to ground
Or
Line to neutral

But how do I test for voltage on the ground ?

Correct me if I am wrong and no offense meant as you are trying to educate yourself. Your question seems to indicate you don’t really understand what voltage, potential and ground actually mean electrically. Voltage is only relevant when referencing one point to another point. “Ground” is often one reference point and it is, regretfully, not THE ground. If we bond the neutral to the ground at the house, for example, and went to an outbuilding where we didn’t drive a ground rod and ad checked voltage from the equipment grounding conductor to the nearby earth you will likely get some voltage.

Remember this. Voltage is a potential. It requires two points. Voltage is from point a to point b, so one must ask, “What is the voltage from ground to earth or neutral?”

 

[jim dungar]

Consider that EG conductor as an extension of your meter lead under normal conditions. Normally there is no current flowing on the EG.

But there is current on the neutral conductor which causes a voltage drop when measured against the groundIng conductor.
We expect the N-G voltage to be zero at the bonding point and a nonzero value further away from that point, depending on loading. For example on long loaded circuit a N-G reading of 0V is could caused by a downstream neutral to ground bond at a receptacle.

While I agree the N-G voltage does not typically mean much on a residential 120/240V installations it can be very helpful in three-phase and SDS systems.

 

[ptonsparky]

But there is current on the neutral conductor which causes a voltage drop when measured against the groundIng conductor.
We expect the N-G voltage to be zero at the bonding point and a nonzero value further away from that point, depending on loading. For example on long loaded circuit a N-G reading of 0V is could caused by a downstream neutral to ground bond at a receptacle.

While I agree the N-G voltage does not typically mean much on a residential 120/240V installations it can be very helpful in three-phase and SDS systems.

I used a Beha tester years ago. IIRC 'continuity' test to about 80K ohms. A N-EG test at the SE with bonded neutral would show nice clean tone. Move the tester down stream with neutral current present and you would hear a 60 cycle hum imposed on that tone. More VD increased the hum to the point it would start indicating voltage on its LED lamps. No digital display. Illicit bonds were very apparent.

 

[The electron man]

In your first three examples, you acknowledge that voltage is measured between two points.

To what point would you want to measure voltage on ground against?

Just want to make sure the ground is not live b4 working on it , I know in most cases its not but you never know

 

[The electron man]

Correct me if I am wrong and no offense meant as you are trying to educate yourself. Your question seems to indicate you don’t really understand what voltage, potential and ground actually mean electrically. Voltage is only relevant when referencing one point to another point. “Ground” is often one reference point and it is, regretfully, not THE ground. If we bond the neutral to the ground at the house, for example, and went to an outbuilding where we didn’t drive a ground rod and ad checked voltage from the equipment grounding conductor to the nearby earth you will likely get some voltage.

Remember this. Voltage is a potential. It requires two points. Voltage is from point a to point b, so one must ask, “What is the voltage from ground to earth or neutral?”

I have lots to learn about theory , but what your saying is since the neutral and ground are bounded they are at the same point and need to points to reference voltage right ? Thanks again

 

[ptonsparky]

You will not normally have voltage difference between neutral and EG. Either one still may have current flowing on them.