Neutral on a dead circuit

teamo

This one has me confused. I am running a timer switch for x-mas lights in the windows in the dining room. I cut in a new outlet under a window where there was no existing outlet. I ran a 12/3 to this outlet from the panel and I broke off the tab on the hot side so I could have one side switched and the other always live. This will not be a 240 volt circuit, I am going to pigtail off of the feed coming from the breaker. The black will feed the bottom of the outlet and the red will go through the timer cabinet to switch the top of the outlet. I pigtailed the switched hot, neutral, and ground and ran a 12/2 out to an existing outlet under another window. At this outlet is the existing circuit which I am going to leave powering the bottom of the outlet and have the new switched circuit power the top of the outlet. I broke off the hot and neutral tabs at this existing outlet so they are totally isolated. I would have just disconnected this original circuit and ran a new three wire over from the new work but the box fill wouldn't work out for the existing outlet and we are probably going to rip all of this out in the next few years when we do an addition. I have not hooked up the 12/3 at the panel yet. I turned on the power to the existing circuit and checked it with my neon tester. The bottom tested hot across the hot and neutral and I also tested across the hot and ground. So far so good. I tested the top of the outlet. No power between hot and neutral and hot and ground. I then tested the live side hot and the neutral for the top outlet which is not wired to the panel yet and I got power. I shut the power removed the outlet from the box, removed the neutral from the top of the outlet and turned the power back on. I tested the live hot side and the neutral terminal which had no wire attached and had no power. I tested between the hot and the now disconnected neutral and got power. Obviously I have to go and pull out the new work but I am not at home right now. I would guess a problem with the neutral and ground somehow not being separate at the new outlet. Maybe the ground is somehow bonded at the new outlet that I installed? Any ideas?

Rochsolid

Yu should of only cut the tab on the hot side of your receptacle

teamo

"Yu should of only cut the tab on the hot side of your receptacle"

Not true. These are two separate circuits. The only time you leave the neutral tab intact is if it is the same circuit for the top and bottom of the device.

Jim Port

It sounds like you are supplying power to both ends of the circuit, one new at the panel and the other end from an existing circuit.

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Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.

AllanJ

If a separate cable hot wire comes in to feed the other half of the duplex receptacle then you must break off the tabs on both sides and each half have its own neutral accompanying its hot wire in the respective cable back to the panel.

Meanwhile all ground wires from all cables are tied together inside the box with one end or pigtail reaching the receptacle green screw.

(My reading comprehension is of too low a grade level for the OP's description so I just threw out the above as a generalized reply.)

__________________
The disadvantages of crab apple trees. In summer, the apples are too sour to pick and eat. In winter the birds come and leave dropping all over the place.

Rochsolid

Th way unread it is that he is feeding the receptacle with 12/3. Perfectly acceptable to share a neutral

dmxtothemax

Think about it !
Do you understand now ?
Please let me know if you dont !

teamo

Then the neutral and earth for the the top recepticule
would still be pig tailed to the bottom of recepticule !
As you only broke the hot link.


I broke off both tabs so there is no pigtailed neutral at the existing outlet. The only pigtailed neutral is in the new outlet. All of the grounds at both receptacles are pigtailed and connected to the ground screw. The three wire is not hooked up in the panel yet it is stripped and capped off at the other end. This will not be a shared neutral 240 circuit. It is only going to be one leg swiched with an intermatic timer and the other leg always hot. One circuit not a mwbc.

If a separate cable hot wire comes in to feed the other half of the duplex receptacle then you must break off the tabs on both sides and each half have its own neutral accompanying its hot wire in the respective cable back to the panel.

Meanwhile all ground wires from all cables are tied together inside the box with one end or pigtail reaching the receptacle green screw.

That is exactly what I did. I am trying to figure out why I am getting a completed circuit on a cable that does not yet have the neutral wire hooked up to the neutral bus in the panel. The only thing I can figure is that the ground is somehow shorted to the neutral at one of the devices or in the cable itself. I will take it all apart tomorrow.

Stubbie

I agree. There is no reason to bring power from another circuit if a 12/3 G homerun is ran to the receptacle. Just break the hot tab run a 12/3 to the timer then you will have a switched wire back to the receptacle. connect the black of 12/3 from panel to the receptacle 1/2 you want constant power and you now essentially have 2 20 amp circuits serving each half of the receptatcle sharing a neutral.

AllanJ

Reviewing the bidding:

The new receptacle has one half controlled by the timer and fed with the red wire of the 12-3. The other half is always hot and fed with the black wire of the 12-3. The neutral side tab should not be broken. If you did break it then use two white pigtails from the 12-3 white wire to connect to the two silver screws (or buy a new receptacle).

Correct, given that half of the existing receptacle will be fed from the new receptacle location and the other half will be fed from the existing circuit. Double check to be sure that wire ends don't stick out too far and touch things they should not, notably where they are screwed onto the receptacle and the pad for the other neutral screw, the two formerly bridged (bonded) with the tab, is very close.

With the 12-3 not connected at the panel yet both of the new receptacle halves and also the half of the existing receptacle fed from the new location should all be dead.

You should get zero volts between any two of the three: hot, neutral, ground at the new receptacle and zero volts between hot of the existing circuit and neutral of the new circuit over at the existing receptacle. Do not use the ohms or continuity function of the meter with the power on.

__________________
The disadvantages of crab apple trees. In summer, the apples are too sour to pick and eat. In winter the birds come and leave dropping all over the place.

teamo

I pulled everything apart. All grounds untwisted, all neutrals, and all hots. Powered up the circuit. Hot to neutral on the old live circuit lights up the neon tester as it should. Hot on the live circuit and neutral on the disconnected circuit and the neon light lit up very faintly. I removed the 12/2 feeding the old receptacle and pulled a new 12/2 cable. I figured something must have pierced the wire, maybe a nail or something in the wall. Tried the same thing with the new cable with nothing twisted and all conductors spread far apart. Still got the faint light on the tester. Could this be some kind of phantom voltage? For now I am going to just cap off the existing circuit and use the new feed from the panel for both receptacles.