DIY Home Improvement, Remodeling & Repair Forum > DIY Home Improvement > Electrical and Wiring > Purpose of neutral wire?




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Old 05-12-2014, 06:16 PM  
Wuzzat?
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As for the neutral, it does the same thing as a ground wire.
Nah, c'mon. . .


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Old 05-12-2014, 06:30 PM  
beachguy005
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I meant that they both run back to the same spot in the panel.



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Old 05-12-2014, 06:41 PM  
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I meant that they both run back to the same spot in the panel.
As it is a true statement, it may not be a good idea to say when someone without expireince is wiring a switch
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Old 05-13-2014, 02:48 PM  
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Thanks, Wuzzat?, you're the only guy to answer my question.

I thought all current flowed from the higher voltage to lower voltage lines (red and black) as the voltage oscillates. I thought the ground wire would draw any current that might not transfer to the lower voltage line. In that case, is the neutral wire unnecessary?

For anyone else, I have connected the neutral wire in my switch the neutral line.

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Old 05-13-2014, 04:32 PM  
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Thanks, Wuzzat?, you're the only guy to answer my question.
>That's because I am educated way beyond my intelligence. . .

I thought all current flowed from the higher voltage to lower voltage lines (red and black) as the voltage oscillates.
>If you have a 0.26 ohm resistance (about 100' of #14 copper) with 10A flowing eastward, the west end will be 2.6v higher, more positive, than the east end.


I thought the ground wire would draw any current that might not transfer to the lower voltage line. In that case, is the neutral wire unnecessary?
>With no fault present, the ground conductor may carry microamps, depending on what's plugged in at the distant end of the cable. The neutral carries the return current which is a much higher current.

>If the appliance fails and some of the current goes to the ground conductor which is probably connected to the appliance's metal case, this conductor will keep the voltage on the case of the appliance very low when measured with respect to earth ground.
If the current in the ground gets high enough the breaker will trip.

>You could run the appliance off the hot and ground wires but that's not the purpose of the ground lead.

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Old 05-13-2014, 05:02 PM  
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Thanks, Wuzzat?, you're the only guy to answer my question.

I thought all current flowed from the higher voltage to lower voltage lines (red and black) as the voltage oscillates. I thought the ground wire would draw any current that might not transfer to the lower voltage line. In that case, is the neutral wire unnecessary?

For anyone else, I have connected the neutral wire in my switch the neutral line.
You are looking at this wrong.
Power comes from the breaker on the black wire to the switch and the black to the fan and then back to the breaker box on the white.
The only reason you have a red wire is because you have a light and a fan and you need to switch them both.

So you have black from the breaker to the two switch black and red from the switch goes to the fan and light. The fan and the light each have a white wire that goes back to the breaker box.

This auto switch also needs a white to make it work but that isn't the normal for most switches.
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Old 05-13-2014, 09:30 PM  
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You are looking at this wrong.
Power comes from the breaker on the black wire to the switch and the black to the fan and then back to the breaker box on the white.
The only reason you have a red wire is because you have a light and a fan and you need to switch them both.

So you have black from the breaker to the two switch black and red from the switch goes to the fan and light. The fan and the light each have a white wire that goes back to the breaker box.

This auto switch also needs a white to make it work but that isn't the normal for most switches.
This Panasonic switch is for the Panasonic condensation fan that does not have a light. The button on the front is to manually activate the condensation fan.
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Old 05-13-2014, 09:32 PM  
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With no fault present, the ground conductor may carry microamps, depending on what's plugged in at the distant end of the cable. The neutral carries the return current which is a much higher current.
So is there fancy internals in the switch that choose where to run the current? Out on the ground line vs the neutral line?

Any reason other appliances don't require such a fancy switch?
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Old 05-13-2014, 10:55 PM  
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I think it's the names that are confusing you. "Neutral" is not neutral in the sense of being unused or unimportant. Back when I was a kid, it was called "Negative" - probably because electricity is explained to kids by using a simple DC circuit. The white (neutral) wire completes the circuit back to the service panel. The "ground wire" is a safety line in case the there is a short circuit in the normal path. It drains the power from the parts you may touch or that may get too hot in your wall. A 3-wire cable (black, white, red...plus ground) is usually just a convenience so you don't have to run extra single wires in cases where it is required.

The Panasonic switch has a lot going on inside that probably requires a second path to the fan (this is a whole house fan or attic fan that we're talking about, right??).

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Old 05-14-2014, 01:13 AM  
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The Panasonic switch has a lot going on inside that probably requires a second path to the fan (this is a whole house fan or attic fan that we're talking about, right??).
Nope, this is a bathroom fan. It's the matching sensor for their bathroom fan.


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