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Apr
3
comment Voltage fluctuations and GFCI tripping drivng me crazy
@ThreePhaseEel: Good point; I was neglecting the fact that the neutral wire is a very low-resistance resistor.
Apr
3
comment Voltage fluctuations and GFCI tripping drivng me crazy
@SomeGuy: Then I am confused, because it seems that we agree that a volt meter will show no voltage on the neutral wire. Yet you claim there is such a voltage, because there is a current. Can you describe an experiment that would measure the AC voltage that you claim is on the neutral wire?
Apr
2
revised Voltage fluctuations and GFCI tripping drivng me crazy
added 446 characters in body
Apr
2
comment Voltage fluctuations and GFCI tripping drivng me crazy
@SomeGuy: My prediction is that current will be nonzero -- about half an amp, AC -- on on both the hot and neutral sides, and voltage will be 120VAC on the hot side and 0VAC on the neutral side. And therefore there is current on the neutral without any voltage. Do you agree or disagree with this prediction? If you disagree, what is your prediction? When you post your prediction, I will attempt the experiment and we will see who is right.
Apr
2
comment Voltage fluctuations and GFCI tripping drivng me crazy
@SomeGuy: Well, clearly we disagree, but we can settle it with science. Run a black wire from a 120VAC breaker to a current meter, then to a 60W light bulb. Then run a white wire from the bulb to a second current meter and then from the current meter to the neutral bus. (Current meters must be installed in series.) Measure the current on the hot and neutral sides. Now remove the current meters and run wires from the white and black wire connections on the bulb to two volt meters, and then attach both volt meters to the safety ground.
Mar
13
comment Attach net/hammock to interior walls
The true tension force you need to overcome is therefore somewhere between 400 pounds at a minimum, and infinity at a maximum, depending on the angle at which you want the hammock to make when loaded. What is that angle? a 400 pound load with an angle of five degrees supplies the equivalent of 5000 pounds of force to the wall, so it matters a lot. Do a web search for "sling angle factor" for charts showing the amount of extra force supplied as a factor of angle.
Mar
13
comment Attach net/hammock to interior walls
Something to keep in mind is that the angle at which the hammock lies when under load dramatically changes the tension force which is applied by the hammock to the walls. Imagine for example you wanted no deflection whatsoever from a horizontal line when the hammock is loaded. Obviously the hammock would have to be infinitely tensioned for that to happen. Now imagine you suspended the hammock from the ceiling straight down, so the angle was purely vertical; clearly the tension with a 400 pound weight is 400 pounds of tension.
Mar
13
comment Is Duck/Duct tape safe to use to insulate mains wires?
Can you more clearly describe the circumstances under which you have non insulated mains wires?
Mar
13
comment water backing up into both sinks, whether running the disposal or dishwasher
You've described a scenario, but you forgot to ask a question. What's your question? "I need help" isn't a question; what specifically do you want to know?
Dec
22
awarded  Peer Pressure
Oct
27
awarded  Yearling
Oct
22
comment Is there a way to change this circuit so that the receptacles are not controlled by switches?
@MarkTraina: That I don't know. I've never seen that behaviour in a multimeter.
Oct
22
comment How do I fix a broken brass drawer pull?
Then I'd go for brazing on new metal as the answer suggests.
Oct
22
comment How do I stop a dimmer switch from humming?
What brand is the dimmer you bought?
Oct
22
suggested rejected edit on Can I branch off of a 2 pole 30 amp 10-3 wire found abandoned in a junction box?
Oct
22
comment Is there a way to change this circuit so that the receptacles are not controlled by switches?
@MarkTraina: Also, as I always counsel people who are getting into homeowner wiring: if you do not have a solid grasp on what the relationships are between volts, amps and watts, if you can't off the top of your head immediately say that a 60W bulb will draw 0.5A on a 120V circuit, then learn that before you go on. You wouldn't want a contractor to work on your house who was not clear on the difference between pounds, inches and minutes, so don't be a guy working on electrics who confuses current, potential and power.
Oct
21
comment Is there a way to change this circuit so that the receptacles are not controlled by switches?
@MarkTraina: More generally, you want the neutrals to have the property that any neutral wire on a given circuit is an uninterrupted path back to the neutral bus on the panel. Similarly for safety grounds; you want there to be one grounding system in the house that all the safety grounds tie into. When I bought my house there were two, and therefore it would be rare but possible to have a voltage difference between them.
Oct
21
comment Is there a way to change this circuit so that the receptacles are not controlled by switches?
@MarkTraina: Imagine a light fixture hooked up directly to the breaker. The light is on all the time. Now you decide to introduce a switch to control the light. You can put the switch on the hot wire or the neutral wire; either will cause the light to go off when the circuit becomes open. But if you switch the neutral then the hot is unswitched and is always providing voltage to the light fixture. That is far more dangerous than the alternative, so code is to always interrupt the hot when you add a switch.
Oct
21
comment Is there a way to change this circuit so that the receptacles are not controlled by switches?
@MarkTraina: An "open" wire is a wire that is not at present connected to anything, so an open ground is what looks like a ground wire, but in fact is not connected to a copper rod driven into the earth anywhere. An open ground is dangerous because it looks like a safety system but in fact is no such thing. An open wire is called that because normally you make a wire open by opening a switch. Internally the switch has a mechanism that physically moves two wire ends together or apart; if there is a gap, no current flows. If the gap is closed, current flows.
Oct
21
comment Is there a way to change this circuit so that the receptacles are not controlled by switches?
@MarkTraina: Not realizing that the ground was open, I tried testing a white wire against the ground, got no voltage, and concluded the white was neutral. It was hot. It was on. I could have shocked myself or others. I should have tested against a known ground rather than assuming incorrectly that the ground was the only correctly wired thing in the box. I have a healthy respect for just how terrible homeowner wiring can be; again, proceed with caution as you learn how to do this.