Outlet tabs ok to remove?

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Linds

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If an outlet's two black wires are on the same circuit, is there a negative to pulling the tab between them?

On the contrary, if the two black wires are different circuits, then not pulling the tab would trip the breaker, right?
 

Reach4

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If an outlet's two black wires are on the same circuit, is there a negative to pulling the tab between them?
I have rethought this. What do you mean by two black wires? It used to be common to power the next outlet in a row that way, where a black came from the breaker panel, and a different black carried power to the next outlet. I think that is not allowed in current codes-- I think they want you to chain to the next with a wire nut. But if it was OK when it was put in, it does not have to be retrofit. Technically (rather than code-required) in my opinion it is fine to daisychain that way. I am not an electrician, and I don't have a problem with the jumpers used for daisy chaining.

But let me say that if the daisy chaining is done that way, just removing the jumper would de-power one or more downstream outlets.

Why do you ask? Been looking in an outlet box, and getting the urge to remove stuff?

On the contrary, if the two black wires are different circuits, then not pulling the tab would trip the breaker, right?
Maybe. If they are on opposite legs (out of phase with each other), yes. If they are on the same leg, then no. However opening one breaker would not kill the power to the circuit, because the other breaker would still supply the circuit.

To not remove the tab in the case you describe is a bad idea -- not just a code violation.
 
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Jadnashua

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IMHO, using the wires on the receptacle as a junction box is not the best practice. I much prefer (assuming they're not two independent circuits), to wire nut the two together, then run a jumper to the receptacle. And, I prefer a receptacle that lets you insert the wire from the back and then use the screw to clamp down on it to tighten things up versus running it underneath the screwhead itself.

Doing it that way means your path on the daisy chain is more robust, and you can remove that device without disrupting everything else downstream. It's also quicker when the time comes to replace it as there's fewer connections to make. Plus, it's easier to push it back into the box since you're then only trying to bend half of the amount of wires. That's especially true on a 20A circuit with its heavier gauge wires.
 

Linds

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Yes. You need the tab to power the other outlet, or you need another wire, to supply the power -- perhaps via a switch.


Maybe. If they are on opposite legs (out of phase with each other), yes. If they are on the same leg, then no. However opening one breaker would not kill the power to the circuit, because the other breaker would still supply the circuit.

Thanks for the reply!
I replaced a couple outlets but forgot to pay attention to which had tabs pulled... Now there are two breakers that once on at the same time causes the other to trip. The interesting thing is that all the outlets still work with leaving either one of tripped breakers off. Haven't found anything that isn't working. My guess is that the breaker is tripping because I forgot to take out a tab, but I have no idea to which one. Might need to go through each one and pull the tabs to check... Any better idea? Or is it fine to leave one of the breakers tripped since I haven't found anything that doesn't work with it off.
 

Reach4

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Don't leave it as is. I am confident you will be able to figure it out.

One idea is to find the other breaker that is shorted together by the extra tab. Let's call that breaker X, and the one that already tripped breaker Y. If you plug an ac-powered radio (if you can find one) into one of the outlets, flip breakers until the radio goes off. That breaker may be breaker X. Then turn breaker Y back on. Does breaker Y or candidate X trip again?
  • If not, the candidate breaker was not the real X. Move the radio to the other outlet you worked on, and try the same test.
  • If the breaker Y or the candidate X does trip again, then remove the jumper where the radio was plugged in.
I am not sure my procedure is good, but I think it is. Somebody may have a better one.

It is possible that both jumpers need to be removed.
 

LLigetfa

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If an outlet's two black wires are on the same circuit, is there a negative to pulling the tab between them?
I fail to comprehend a valid reason to have two feeds to an outlet where the feeds are both on the same leg. In such a situation, if they share the neutral, then you could current overload it. Also AFAIK when two circuits feed the outlet, they should be ganged so that if one trips, the other is taken out with it.
 

Reach4

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I fail to comprehend a valid reason to have two feeds to an outlet where the feeds are both on the same leg. In such a situation, if they share the neutral, then you could current overload it. Also AFAIK when two circuits feed the outlet, they should be ganged so that if one trips, the other is taken out with it.
Sometimes one is switched. The single pole breaker limits both top and bottom however. Sometimes you want the top outlet able to provide 15 amps and the bottom outlet to also provide 15 amps at the same time.

I used the word leg to indicate circuits which get their hots from the same side of the pole transformer. If you use the word phase to make that distinction on a split phase system, stand back and wait for a strong reaction. :D https://en.wikipedia.org/wiki/Split-phase_electric_power

Sometimes you do that and it is not a MWBC and there is not the switch thing happening. Clearly in that 2-breaker case, the neutrals should be separate also. If it is a MWBC, then top and bottom are fed with different legs via a 2-pole breaker or at least one where the breaker handles are linked in a prescribed way.
 
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Jadnashua

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Many 15A receptacles are 20A pass-through, so you should not be able to overload it without tripping the protection circuit, even when it's on a 20A circuit.

You may have more than one receptacle that is fed by two circuits.

First, you should be able to eliminate any that only have one cable attached.

On any that have two cables (or more), remove one hot lead from each receptacle. Turn power back on...see if the breaker trips. If it doesn't, turn things back off and one by one, attach the removed hot lead back. Turn power on, if it trips, break the tab. Continue through the rest of them in case there's a second one that needs the tab broken. Once you've reached the final one, power should stay on in both circuits.

It is possible that one wire run feeds multiple receptacles...if so, you'll have to break the tab on more than one of them.

Once you've fixed things so they all stay on and all ports work, you should either replace that breaker with a dual one, or buy the handle that connects them together so if one side trips, it shuts the other one off, too. Otherwise, someone turning one breaker off may end up thinking all power is off in that box, and find out they only got half of it...it could be quite a shock.

If you have GFCI protection, to ensure things work properly, when you have to break one tab, you should probably break the neutral tab too...but, make sure the hot and neutral from a single cable are not crossed with the other one feeding the box...eg., if the top receptacle is being fed, make sure it's companion neutral is attached to the neutral side of the same receptacle.
 

Linds

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Thank you all for your help! Through some of the answers here, trying to remove a tab in an outlet and seeing that it killed the rest of the series, and some deep thinking, I found that it wasn't an outlet at all, but a switch!

It turns out the ceiling lights in the basement (top right switch in my picture) are wired to a breaker that is connected to the some things on the 1st floor. The double switch had a tab that I needed to break to disconnect the basement breaker from the upstairs one.

Thanks for all the help, this venture in switching out black outlets and switches for white has helped me learn A LOT about my home's wiring. On to the next project!
 

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