Question: Is this supposed to be hot?

[xyster101]

I did some work in my panel and I pulled a neutral off the bar and it sparked. After a few hours I traced it back to the remote boxes on 2 different brand ceiling fans.
When I hook the HOT wire to the remote control box in the fan, the neutral wiring coming out has 120 volts. It reads 108 on my meter and makes my AC sniffer beep.
When the neutrals are all hooked up I get 120 volts at neutrals on outlets. It has been this way for 4 years and things plugged in work fine.

Why am I getting 120 volts on the neutral of these fan remote boxes?

 

[Lonnies Performance]

Electrical circuits function by completing a loop...

The 120v-Hot sends power to the device & it returns to it's source, the neutral.

At any point, all wires have can 120V on them.
The remote boxes draw a small current to keep them active, even when the fan is off.

The neutral has powar going through it. The only reason you don't read power & essentially can touch the neutral bar (not recommended) is that it is a better ground than you are & all power is in reality seeking a ground path.

 

[Richard Cranium]

Great answer Lonnies

 

[checkthisout]

I did some work in my panel and I pulled a neutral off the bar and it sparked. After a few hours I traced it back to the remote boxes on 2 different brand ceiling fans.
When I hook the HOT wire to the remote control box in the fan, the neutral wiring coming out has 120 volts. It reads 108 on my meter and makes my AC sniffer beep.
When the neutrals are all hooked up I get 120 volts at neutrals on outlets. It has been this way for 4 years and things plugged in work fine.

Why am I getting 120 volts on the neutral of these fan remote boxes?

You get 120v between neutral and what other conductor?

 

[xyster101]

Lonnies,

Thanks. That was my thinking, but I was not sure. I tested a light and when it was turned on, the neutral did not make the AC sniffer beep.

 

[wyliesdiesels]

I did some work in my panel and I pulled a neutral off the bar and it sparked. After a few hours I traced it back to the remote boxes on 2 different brand ceiling fans.
When I hook the HOT wire to the remote control box in the fan, the neutral wiring coming out has 120 volts. It reads 108 on my meter and makes my AC sniffer beep.
When the neutrals are all hooked up I get 120 volts at neutrals on outlets. It has been this way for 4 years and things plugged in work fine.

Why am I getting 120 volts on the neutral of these fan remote boxes?

What kind of breaker are these circuits connected to? Single pole or double pole?

Sounds like you might be working on a MWBC- multi-wire branch circuit.

 

[sberry]

In 120v circuit it isn't a neutral but a grounded conductor. If you disconnect it and put it on series there will be 120v on it if the switch is on. When it's grounded its a current carrying conductor, carrying the same as the hot side. No real voltage as it is grounded. Open it voltage goes to 120 as current drops.

 

[Aceman]

Disconnecting the neutral on an energized circuit with a load(specifically electronics) is a good way to ruin equipment.

I'd recommend turning off circuits before working on them.

 

[Marctrees]

Long version of what sberry and lonnies said above..

When the ckt is closed and current flows the primary voltage drop is across the main load.. in this case a fan.

A bit of voltage is dropped also along the whole conductor path, negligible in a correctly sized wire ckt, but like close to ballpark 98% is dropped across the main load.

If you have a currently enegized ckt, meaning like a switch is on, When the neutral is lifted off the bus, you have opened the ckt, and now, w no current flow, the entire full 100% of the voltage will show at the open.

Even if that wire is a mile long, you will still have the full 100% potential equally EVERYWHERE on that wire, even though it is so darn long.

Only when the ckt is closed and you have current flow, only then will you read slightly varying voltage on that mile long wire, due now.. to line drop due to NO conductor is truly zero resistance.

And yes, you can get a shock by holding that open neutral, unless your body is isolated from Ground.

JUST as potentially lethal as grabbing a Hot.

Human body is MUCH higher resistance than a fan or light bulb, so by far the majority of total ckt voltage will be dropped across the body.

So, Gentlemen, be aware you can get killed by touching a Neutral..but only if the ckt is open at that spot.

Yet another example of why you really need to know what one is doing, especially working hot.

A neutral is called the "Grounded Conductor"... NOT to be confused or sloppily talk interchanged w "Grounding Conductor"..

Grounded conductor carries current when ckt is closed...

Grounding Conductor ONLY carries fault current.

Marc

 

[PassnThru]

This reminds me of my shower light story. Not long ago, I replaced the bulb in the light above the shower in our master bath with a dimmable LED. I went to bed that night and discovered that, in the dark, the light over the shower was glowing ever so lightly. The switch was off - why was the bulb getting current?
Worked on it the next day. I had a lighted switch on that fixture - it was the smallest bulb in the bath so it got middle of the night nature calls duty.
Apparently, the switch passed enough current to light itself that it also lit what was apparently an extremely competent LED bulb for dimming purposes. It carried the same current to the old filament bulb - but it wasn't enough to produce light.
Had to give up the lighted switch to solve the problem.

 

[xyster101]

Thanks all. I don't work on circuits "live" as I know I will touch something or cross something by accident. In this case, the neutral I was unhooking from the bus bar in the panel was supposed to be off. I traced the wire wrong and I ended up taking off a live circuit by accident.

 

[nsula_country]

I did some work in my panel and I pulled a neutral off the bar and it sparked. After a few hours I traced it back to the remote boxes on 2 different brand ceiling fans.
When I hook the HOT wire to the remote control box in the fan, the neutral wiring coming out has 120 volts. It reads 108 on my meter and makes my AC sniffer beep.
When the neutrals are all hooked up I get 120 volts at neutrals on outlets. It has been this way for 4 years and things plugged in work fine.

Why am I getting 120 volts on the neutral of these fan remote boxes?

You are using a high impedance meter. If you used a wiggy or a test light, I'd bet it would read 0 volts. Small solid state devices with triac outputs (not relays) have micro amp leakage by nature.

Or... You are dealing with a MWBC.

CT

 

[checkthisout]

If you have power to the fan control boxes and you disconnect the neutral at the panel then you will read 120V on the neutrals because the circuit is incomplete.

It's the same thing as having a continuous wire from the hot to wherever you are testing.

That is why I asked what two wires you are placing your volt meter in between to get the reading you are getting.

Not enough information here to answer your question and I am surprised that anyone was able to.

 

[thewatusi]

Thanks all. I don't work on circuits "live" as I know I will touch something or cross something by accident. In this case, the neutral I was unhooking from the bus bar in the panel was supposed to be off. I traced the wire wrong and I ended up taking off a live circuit by accident.

Excellent example of why you should shut off the entire panel before opening it up and doing anything.

 

[canbug]

I've been an electrician for 33 years and the worst shock I ever took was from an open neutral. Not something you want to play with.

Tim.

 

[AntonLargiader]

Excellent example of why you should shut off the entire panel before opening it up and doing anything.

In my old shop I ran into the same issue and the neutral was energized from a different panel. This was an old roller rink that had been split up into separate commercial spaces through a series of half-assed modifications. Getting my electrical service isolated to just my space was a challenge and it left a different tenant without power for two weeks.

When the building sold, the new owner pretty much gutted it and started over.

FWIW that building was 120/208 3-phase. No actual 240 to be had anywhere.