Here is another thing bothering me. This has been unresolved in my mind for 40 years. I have done a lot of work inside of electrical panels (US 240 VAC 1p). I'm looking at the black wire, the so-called hot (L1) coming out of a single pole 20A breaker. It is daisy chained to 5 outlets (in parallel) which may have a lamp or a drill motor a toaster or whatever plugged into them at any given time. After the last outlet in this circuit the white wire, so-called neutral (using 12 AWG NM) comes back to a bus bar in the bonded main electrical panel. I have never intentionally touched that black wire coming from the breaker. I can touch that neutral/ground bus without issue. My question is, if this AC current is going from a max positive to a max negative, a direction reversal, shouldn't that neutral wire shock me depending on where it is in its AC cycle. Doesn't the neutral become so-called hot for half of that sine wave?

 

You can touch the neutral at the box because it is or at least should be bonded directly to the ground bar.

Personally, I wouldn't recommend touching anything in the box.

 

You have to have connections to two different potentials in order for current to flow. When you touch live, the other potential is ground (earth), through your feet, and you get a shock. Neutral is at the same potential as ground, so there can be no current flow from the neutral bus to ground through your feet.

 

You have to have connections to two different potentials in order for current to flow. When you touch live, the other potential is ground (earth), through your feet, and you get a shock. Neutral is at the same potential as ground, so there can be no current flow from the neutral bus to ground through your feet.

Bob, for argument's sake, I'm standing on my concrete floor and I'm touching the neutral bus which at times becomes "hot" but so does the floor?

 

You can touch the neutral at the box because it is or at least should be bonded directly to the ground bar.

Personally, I wouldn't recommend touching anything in the box.

Yes I said it was bonded.

 

The neutral never becomes "hot" unless something is wrong.

Don't confuse the positive phase with "hot".

 

The neutral never becomes "hot" unless something is wrong.

The hot is in quotes because it's not really hot hot but electrons are flowing to (toward) hot instead of from it during reversal.

 

You have to have connections to two different potentials in order for current to flow. When you touch live, the other potential is ground (earth), through your feet, and you get a shock. Neutral is at the same potential as ground, so there can be no current flow from the neutral bus to ground through your feet.

Bob , I think you helped me clear this up in my mind. Regardless of the current direction (as determined by the sine wave) I'm "always" at the same potential as the neutral?

 

View the supply without any earth conductor connection, The supply changes polarity twice each cycle. There is no difference between either conductor where voltage is concerned.
In your case one is bonded to earth.

 

View the supply without any earth conductor connection, The supply changes polarity twice each cycle. There is no difference between either conductor where voltage is concerned.
In your case one is bonded to earth.

Max, if there was no earth conductor, no bonding. I would get zapped touching the neutral?

 

Yes. The neutral is identical to the 'live' conductor, just that is is 'neutralized' against shock by being connected to earth, in every other respect, it is identical to the 'live' phase.
In any AC supply, any conductor can be connected to earth, in order to provide a neutral.
In other parts of the world thjat use one phase of a three phase supply domestic residences are supplied with a earthed star point of a 3ph transformer, same principle and effect.

 

Based on comments here, I suggest you stop poking around inside breaker panels.

Please take a minute to understand this. If you disconnect the neutral (white) wire from the neutral bar, and touch that disconnected white wire and neutral or ground, you WILL receive a potentially fatal shock. The entire load on that circuit will be attempting to take a shortcut through your body.

 

Yes. The neutral is identical to the 'live' conductor, just that is is 'neutralized' against shock by being connected to earth, in every other respect, it is identical to the 'live' phase.
In any AC supply, any conductor can be connected to earth, in order to provide a neutral.
In other parts of the world thjat use one phase of a three phase supply domestic residences are supplied with a earthed star point of a 3ph transformer, same principle and effect.

Wow, I did not know that. I thought neutral was earthed at the power plant. Thanks for that information.

 

Max, if there was no earth conductor, no bonding. I would get zapped touching the neutral?

If instead of you body you put a DMM between a conductor and something else (another phase, the grounded conductor, the earth, &c.) You are measuring the potential between those two points. If you touch the neutral and don't get a shock it means there is no (or very little) potential between you and that point.

Now imagine you have a perfectly operational radar speed gun and you point it at a mountain reading 60MPH. The radar gun is completely in order. How can the mountain be moving at 60MPH?

 

Wow, I did not know that. I thought neutral was earthed at the power plant. Thanks for that information.

In NA domestic supply It is grounded at the centre tap of a 120v-0-120v local tranformer secondary .
In other jurisdictions, the local 3ph transformer has a delta connected secondary and the neutral-star point is connected to earth.

 

Based on comments here, I suggest you stop poking around inside breaker panels.

Please take a minute to understand this. If you disconnect the neutral (white) wire from the neutral bar, and touch that disconnected white wire and neutral or ground, you WILL receive a potentially fatal shock. The entire load on that circuit will be attempting to take a shortcut through your body.

Yes that I am aware of. At first I thought you were talking about the bare copper that comes into the panel with l1 and l2.

 

You might want to read about the UK focus on making things equipotential.

 

The neutral never becomes "hot" unless something is wrong.

Don't confuse the positive phase with "hot".

ESpidey, I think this was a big part of my question and my thinking. Equating positive part of wave with "hot"

 

The Neutral bus should NOT be HOT. That tells me that even if no one circuit is tripping its breaker that the total load for all of the circuits together is overloading panel. Warm possibly, but not hot! What is the rating of the mains breaker? And what total load is the panel rated for? Something sounds off... If you can, thermal image the panel with the cover plate removed.

 

The Neutral bus should NOT be HOT. That tells me that even if no one circuit is tripping its breaker that the total load for all of the circuits together is overloading panel. Warm possibly, but not hot! What is the rating of the mains breaker? And what total load is the panel rated for? Something sounds off... If you can, thermal image the panel with the cover plate removed.

Sam I am not having any electrical problems here. I'm just trying to understand AC electricity, I used my panel box as an example, what I was trying to figure out is if the voltage and current go back-and-forth 60 times per second why doesn't my white neutral wire become like the black L1 wire for half of the cycle and electrify the main panel. ElecSpidey in post #6 may have clearified this for me.