Voltage testing

[jim dungar]

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

Many electricians treat 'ground' as their primary reference point. Many also treat neutral and ground as being the same point even though that is true only at their common point. Many electricians have experienced the thrill of opening a neutral connection on a multi-wire or a mis-wired branch circuit even though the line-ground voltage was zero.
I always measure the N-G voltage as part of troubleshooting and when verifying de-energized.

Yes you need two points to measure a voltage. These points may vary for each measurement, so it is a good idea to mention which ones you used along with the results.

 

[Sea Nile]

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

This is one of many free videos, I got a lot out of this one.

 

[Strathead]

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

Also reference your question to my post. Current flows “you get shocked” when there is a difference in voltage potential between two conductive things you are touching. As such, if I test the ground to the neutral and read 0 I won’t get shocked there. Between the ground and a metal outlet box 0 no shock. Between the found and a reachable metal enclosure or wet concrete and no shock. If nothing is reachable, then also no shock. The last is true even if there is system voltage on the ground. This might help. Get really simple. An electron has to have a path from the source (one side of the utility transformer, or for our purposes a hot wire at the service) across wires metal enclosures etc. Through the load or your body, then back to the source on another path. Whether that path is another phase hot, the neutral, or an unintended path like through you to wet shoes to a puddle, to the earth, to the ground rod, to the neutral ground bond, then along the neutral back to the transformer.

 

[LarryFine]

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 best way to detect for 'hot' relative to the rest of the world is with a non-contact voltage tester.

I like the kind with dual voltage (i.e., sensitivity) ranges.

 

[ptonsparky]

I like the kind with dual voltage (i.e., sensitivity) ranges.

I haven't seen those. Link?

 

[LarryFine]

I haven't seen those. Link?

Klein Tools Dual Range Non Contact Voltage Tester, 12-1000V AC NCVT-2PR - The Home Depot

The NCVT-2P is a non-contact voltage tester that detects 12 to 1000V AC and indicates the presence of voltage in cables, cords, circuit breakers, light fixtures, switches, outlets and wires as well as

www.homedepot.com

Southwire Advanced AC Non Contact Voltage Tester Pen, 2-1000-Volt AC/100-Volt-1000-Volt AC 63020740 - The Home Depot

The Southwire Tools and Equipment 40150N is an advanced dual range non-contact AC voltage detector with a convenient work light. It features audible and visual indication of AC voltage on 2 ranges: 12-Volt

www.homedepot.com

 

[don_resqcapt19]

The best way to detect for 'hot' relative to the rest of the world is with a non-contact voltage tester.

I like the kind with dual voltage (i.e., sensitivity) ranges.

But never trust the results of that type of voltage indicator. The instructions form every manufacturer tell you that.

 

[jim dungar]

But never trust the results of that type of voltage indicator. The instructions form every manufacturer tell you that.

Agree.
These are good for indicating voltage, they are lousy at indicating no voltage.