OK, let me explain some things. There are 2 problems: one related to measuring AC voltage between Hot and Neutral in a ceiling point, and another one the breaker tripping when I soldered the neutral.
1. The one I didn't understand was the DMM reading 20-60V AC between Hot and Neutral with the ceiling switch off. I am learning now that there can be stray voltage and that I should short both wires (load with a light bulb I mean, for example), even after switching off, to drain whatever remnant voltage. I am curious about that and will try it in my own home one of these days. My question here is... is stray voltage really an equivalent of saying that the 2 wires are somehow "charged" with so very little energy @20-60V, and that the DMM is reading that? So if I drain with a bulb the stray voltage, REMOVE the bulb, and check again, I should read almost 0V? Or does the stray voltage come back when there is no load?
2. The other problem is my iron, which tip is grounded, and when I touched the switched off neutral (which now I believe is not affected by the switch and is still connected to the rest of the house circuit), the main breaker tripped. I was not understanding this because if neutral is at 0V, and ground is 0V, there is no current and I don't understand how that could trip anything. Now I am learning that you guys say there can be some voltage in neutral and that can go to ground and trip the breaker.
Is is that the correct answer, or this is not voltage dependent, but simply whenever you short neutral and earth you are going to trip the main breaker, no matter if there is current flowing or not?
1. The one I didn't understand was the DMM reading 20-60V AC between Hot and Neutral with the ceiling switch off. I am learning now that there can be stray voltage and that I should short both wires (load with a light bulb I mean, for example), even after switching off, to drain whatever remnant voltage. I am curious about that and will try it in my own home one of these days. My question here is... is stray voltage really an equivalent of saying that the 2 wires are somehow "charged" with so very little energy @20-60V, and that the DMM is reading that? So if I drain with a bulb the stray voltage, REMOVE the bulb, and check again, I should read almost 0V? Or does the stray voltage come back when there is no load?
2. The other problem is my iron, which tip is grounded, and when I touched the switched off neutral (which now I believe is not affected by the switch and is still connected to the rest of the house circuit), the main breaker tripped. I was not understanding this because if neutral is at 0V, and ground is 0V, there is no current and I don't understand how that could trip anything. Now I am learning that you guys say there can be some voltage in neutral and that can go to ground and trip the breaker.
Is is that the correct answer, or this is not voltage dependent, but simply whenever you short neutral and earth you are going to trip the main breaker, no matter if there is current flowing or not?